[PATCH 0/6] bootstd: Add Android support

[PATCH 0/6] bootstd: Add Android support

[Mattijs Korpershoek]

Android boot flow is a bit different than a regular Linux distro.
Android relies on multiple partitions in order to boot.

A typical boot flow would be:
1. Parse the Bootloader Control Block (BCB, misc partition)
2. If BCB requested bootonce-bootloader, start fastboot and wait.
3. If BCB requested recovery or normal android, run the following:
   a. Get slot (A/B) from BCB
   b. Run AVB (Android Verified Boot) on boot partitions
   c. Load boot and vendor_boot partitions
   d. Load device-tree, ramdisk and boot

The AOSP documentation has more details at [1], [2], [3]

This has been implemented via complex boot scripts such as [4].
However, these boot script are neither very maintainable nor generic.
Moreover, DISTRO_DEFAULTS is being deprecated [5].

Add a generic Android bootflow implementation for bootstd.

For this initial version, only boot image v4 is supported.

This has been tested on sandbox using:
$ ./test/py/test.py --bd sandbox --build -k test_ut

This has also been tested on the AM62X SK EVM using TI's Android SDK[6]
To test on TI board, the following (WIP) patch is needed as well:
https://gitlab.baylibre.com/baylibre/ti/ti-u-boot/-/commit/84cceb912bccd7cdd7f9dd69bca0e5d987a1fd04

[1] https://source.android.com/docs/core/architecture/bootloader
[2] https://source.android.com/docs/core/architecture/partitions
[3] https://source.android.com/docs/core/architecture/partitions/generic-boot
[4] https://source.denx.de/u-boot/u-boot/-/blob/master/include/configs/meson64_android.h
[5] https://lore.kernel.org/r/all/20230914165615.1058529-17-sjg@chromium.org/
[6] https://software-dl.ti.com/processor-sdk-android/esd/AM62X/09_02_00/docs/android/Overview.html

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
Mattijs Korpershoek (6):
      boot: android: Provide vendor_bootimg_addr in boot_get_fdt()
      boot: android: Add image_android_get_version()
      bootstd: Add bootflow_iter_check_mmc() helper
      android: boot: Add set_abootimg_addr() and set_avendor_bootimg_addr()
      bootstd: Add a bootmeth for Android
      bootstd: Add test for bootmeth_android

 MAINTAINERS               |   7 +
 arch/sandbox/dts/test.dts |   8 +
 boot/Kconfig              |  14 ++
 boot/Makefile             |   2 +
 boot/bootflow.c           |  12 ++
 boot/bootmeth_android.c   | 522 ++++++++++++++++++++++++++++++++++++++++++++++
 boot/bootmeth_android.h   |  27 +++
 boot/image-android.c      |   7 +-
 boot/image-fdt.c          |   2 +-
 cmd/abootimg.c            |  10 +
 configs/sandbox_defconfig |   2 +-
 doc/develop/bootstd.rst   |   6 +
 include/bootflow.h        |   9 +
 include/image.h           |  21 ++
 test/boot/bootflow.c      |  65 +++++-
 test/py/tests/test_ut.py  |  76 +++++++
 16 files changed, 784 insertions(+), 6 deletions(-)
---
base-commit: 227be29df37545f74243a98c12a4a33c4160e3cd
change-id: 20240605-bootmeth-android-bfc8596e9367

Best regards,
-- 
Mattijs Korpershoek <mkorpershoek@baylibre.com>

[PATCH 1/6] boot: android: Provide vendor_bootimg_addr in boot_get_fdt()

[Mattijs Korpershoek]

When calling android_image_get_dtb_by_index() using boot image v3+,
we should also pass the vendor_boot ramdisk address.

Use get_avendor_bootimg_addr() to do so.

Note: on boot image v2, this is harmless since get_avendor_bootimg_addr()
returns -1.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 boot/image-fdt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/boot/image-fdt.c b/boot/image-fdt.c
index 56dd7687f51c..8332792b8e80 100644
--- a/boot/image-fdt.c
+++ b/boot/image-fdt.c
@@ -502,7 +502,7 @@ int boot_get_fdt(void *buf, const char *select, uint arch,
 		 * Firstly check if this android boot image has dtb field.
 		 */
 		dtb_idx = (u32)env_get_ulong("adtb_idx", 10, 0);
-		if (android_image_get_dtb_by_index((ulong)hdr, 0,
+		if (android_image_get_dtb_by_index((ulong)hdr, get_avendor_bootimg_addr(),
 						   dtb_idx, &fdt_addr, &fdt_size)) {
 			fdt_blob = (char *)map_sysmem(fdt_addr, 0);
 			if (fdt_check_header(fdt_blob))

-- 
2.45.0

[PATCH 2/6] boot: android: Add image_android_get_version()

[Mattijs Korpershoek]

When reading a boot image header, we may need to retrieve the header
version.

Add a helper function for it.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 boot/image-android.c | 7 ++++++-
 include/image.h      | 7 +++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/boot/image-android.c b/boot/image-android.c
index ddd8ffd5e540..4f8fb51585eb 100644
--- a/boot/image-android.c
+++ b/boot/image-android.c
@@ -185,7 +185,7 @@ bool android_image_get_data(const void *boot_hdr, const void *vendor_boot_hdr,
 		return false;
 	}
 
-	if (((struct andr_boot_img_hdr_v0 *)boot_hdr)->header_version > 2) {
+	if (android_image_get_version(boot_hdr) > 2) {
 		if (!vendor_boot_hdr) {
 			printf("For boot header v3+ vendor boot image has to be provided\n");
 			return false;
@@ -203,6 +203,11 @@ bool android_image_get_data(const void *boot_hdr, const void *vendor_boot_hdr,
 	return true;
 }
 
+u32 android_image_get_version(const void *hdr)
+{
+	return ((struct andr_boot_img_hdr_v0 *)hdr)->header_version;
+}
+
 static ulong android_image_get_kernel_addr(struct andr_image_data *img_data)
 {
 	/*
diff --git a/include/image.h b/include/image.h
index acffd17e0dfd..18e5ced5ab42 100644
--- a/include/image.h
+++ b/include/image.h
@@ -1963,6 +1963,13 @@ bool is_android_boot_image_header(const void *hdr);
  */
 bool is_android_vendor_boot_image_header(const void *vendor_boot_img);
 
+/**
+ * android_image_get_version() - Retrieve the boot.img version
+ *
+ * Return: Android boot image header version.
+ */
+u32 android_image_get_version(const void *hdr);
+
 /**
  * get_abootimg_addr() - Get Android boot image address
  *

-- 
2.45.0

[PATCH 3/6] bootstd: Add bootflow_iter_check_mmc() helper

[Mattijs Korpershoek]

Some bootflows might be able to only boot from MMC devices.

Add a helper function these bootflows can use.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 boot/bootflow.c    | 12 ++++++++++++
 include/bootflow.h |  9 +++++++++
 2 files changed, 21 insertions(+)

diff --git a/boot/bootflow.c b/boot/bootflow.c
index 9aa3179c3881..59d77d2385f4 100644
--- a/boot/bootflow.c
+++ b/boot/bootflow.c
@@ -575,6 +575,18 @@ int bootflow_iter_check_blk(const struct bootflow_iter *iter)
 	return -ENOTSUPP;
 }
 
+int bootflow_iter_check_mmc(const struct bootflow_iter *iter)
+{
+	const struct udevice *media = dev_get_parent(iter->dev);
+	enum uclass_id id = device_get_uclass_id(media);
+
+	log_debug("uclass %d: %s\n", id, uclass_get_name(id));
+	if (id == UCLASS_MMC)
+		return 0;
+
+	return -ENOTSUPP;
+}
+
 int bootflow_iter_check_sf(const struct bootflow_iter *iter)
 {
 	const struct udevice *media = dev_get_parent(iter->dev);
diff --git a/include/bootflow.h b/include/bootflow.h
index 080ee8501225..6058ddd89b16 100644
--- a/include/bootflow.h
+++ b/include/bootflow.h
@@ -407,6 +407,15 @@ void bootflow_remove(struct bootflow *bflow);
  */
 int bootflow_iter_check_blk(const struct bootflow_iter *iter);
 
+/**
+ * bootflow_iter_check_mmc() - Check that a bootflow uses a MMC device
+ *
+ * This checks the bootdev in the bootflow to make sure it uses a mmc device
+ *
+ * Return: 0 if OK, -ENOTSUPP if some other device is used (e.g. ethernet)
+ */
+int bootflow_iter_check_mmc(const struct bootflow_iter *iter);
+
 /**
  * bootflow_iter_check_sf() - Check that a bootflow uses SPI FLASH
  *

-- 
2.45.0

[PATCH 4/6] android: boot: Add set_abootimg_addr() and set_avendor_bootimg_addr()

[Mattijs Korpershoek]

The only way to configure the load addresses for both bootimg and
vendor_bootimg is by using the "abootimg" command.
If we want to use the C API, there is no equivalent.

Add set_abootimg_addr() and set_avendor_bootimg_addr() so that we can
specify the load address from C.

This can be useful for implementing an Android bootmethod.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 cmd/abootimg.c  | 10 ++++++++++
 include/image.h | 14 ++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/cmd/abootimg.c b/cmd/abootimg.c
index 88c77d999290..33381e22dec2 100644
--- a/cmd/abootimg.c
+++ b/cmd/abootimg.c
@@ -21,11 +21,21 @@ ulong get_abootimg_addr(void)
 	return (_abootimg_addr == -1 ? image_load_addr : _abootimg_addr);
 }
 
+void set_abootimg_addr(ulong addr)
+{
+	_abootimg_addr = addr;
+}
+
 ulong get_avendor_bootimg_addr(void)
 {
 	return _avendor_bootimg_addr;
 }
 
+void set_avendor_bootimg_addr(ulong addr)
+{
+	_avendor_bootimg_addr = addr;
+}
+
 static int abootimg_get_ver(int argc, char *const argv[])
 {
 	const struct andr_boot_img_hdr_v0 *hdr;
diff --git a/include/image.h b/include/image.h
index 18e5ced5ab42..6deaf406605e 100644
--- a/include/image.h
+++ b/include/image.h
@@ -1977,6 +1977,13 @@ u32 android_image_get_version(const void *hdr);
  */
 ulong get_abootimg_addr(void);
 
+/**
+ * set_abootimg_addr() - Set Android boot image address
+ *
+ * Return: no returned results
+ */
+void set_abootimg_addr(ulong addr);
+
 /**
  * get_avendor_bootimg_addr() - Get Android vendor boot image address
  *
@@ -1984,6 +1991,13 @@ ulong get_abootimg_addr(void);
  */
 ulong get_avendor_bootimg_addr(void);
 
+/**
+ * set_abootimg_addr() - Set Android vendor boot image address
+ *
+ * Return: no returned results
+ */
+void set_avendor_bootimg_addr(ulong addr);
+
 /**
  * board_fit_config_name_match() - Check for a matching board name
  *

-- 
2.45.0

[PATCH 5/6] bootstd: Add a bootmeth for Android

[Mattijs Korpershoek]

Android boot flow is a bit different than a regular Linux distro.
Android relies on multiple partitions in order to boot.

A typical boot flow would be:
1. Parse the Bootloader Control Block (BCB, misc partition)
2. If BCB requested bootonce-bootloader, start fastboot and wait.
3. If BCB requested recovery or normal android, run the following:
3.a. Get slot (A/B) from BCB
3.b. Run AVB (Android Verified Boot) on boot partitions
3.c. Load boot and vendor_boot partitions
3.d. Load device-tree, ramdisk and boot

The AOSP documentation has more details at [1], [2], [3]

This has been implemented via complex boot scripts such as [4].
However, these boot script are neither very maintainable nor generic.
Moreover, DISTRO_DEFAULTS is being deprecated [5].

Add a generic Android bootflow implementation for bootstd.
For this initial version, only boot image v4 is supported.

[1] https://source.android.com/docs/core/architecture/bootloader
[2] https://source.android.com/docs/core/architecture/partitions
[3] https://source.android.com/docs/core/architecture/partitions/generic-boot
[4] https://source.denx.de/u-boot/u-boot/-/blob/master/include/configs/meson64_android.h
[5] https://lore.kernel.org/r/all/20230914165615.1058529-17-sjg@chromium.org/

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 MAINTAINERS             |   7 +
 boot/Kconfig            |  14 ++
 boot/Makefile           |   2 +
 boot/bootmeth_android.c | 522 ++++++++++++++++++++++++++++++++++++++++++++++++
 boot/bootmeth_android.h |  27 +++
 doc/develop/bootstd.rst |   6 +
 6 files changed, 578 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 66783d636e3d..6d2b87720565 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -939,6 +939,13 @@ F:	include/bootstd.h
 F:	net/eth_bootdevice.c
 F:	test/boot/
 
+BOOTMETH_ANDROID
+M:	Mattijs Korpershoek <mkorpershoek@baylibre.com>
+S:	Maintained
+T:	git https://source.denx.de/u-boot/custodians/u-boot-dfu.git
+F:	boot/bootmeth_android.c
+F:	boot/bootmeth_android.h
+
 BTRFS
 M:	Marek Behún <kabel@kernel.org>
 R:	Qu Wenruo <wqu@suse.com>
diff --git a/boot/Kconfig b/boot/Kconfig
index 6f3096c15a6f..5fa6f3b8315d 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -494,6 +494,20 @@ config BOOTMETH_GLOBAL
 	  EFI bootmgr, since they take full control over which bootdevs are
 	  selected to boot.
 
+config BOOTMETH_ANDROID
+	bool "Bootdev support for Android"
+	depends on X86 || ARM || SANDBOX
+	select ANDROID_AB
+	select ANDROID_BOOT_IMAGE
+	select CMD_BCB
+	select PARTITION_TYPE_GUID
+	select PARTITION_UUIDS
+	help
+	  Enables support for booting Android using bootdevs. Android requires
+	  multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
+
+	  Note that only MMC bootdevs are supported at present.
+
 config BOOTMETH_CROS
 	bool "Bootdev support for Chromium OS"
 	depends on X86 || ARM || SANDBOX
diff --git a/boot/Makefile b/boot/Makefile
index 84ccfeaecec4..75d1cd46fabf 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -66,3 +66,5 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_REQUEST) += vbe_request.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o
+
+obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_ANDROID) += bootmeth_android.o
diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c
new file mode 100644
index 000000000000..26d548d2fd6e
--- /dev/null
+++ b/boot/bootmeth_android.c
@@ -0,0 +1,522 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Bootmethod for Android
+ *
+ * Copyright (C) 2024 BayLibre, SAS
+ * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
+ */
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include <android_ab.h>
+#include <android_image.h>
+#if CONFIG_IS_ENABLED(AVB_VERIFY)
+#include <avb_verify.h>
+#endif
+#include <bcb.h>
+#include <blk.h>
+#include <bootflow.h>
+#include <bootm.h>
+#include <bootmeth.h>
+#include <dm.h>
+#include <image.h>
+#include <malloc.h>
+#include <mapmem.h>
+#include <part.h>
+#include "bootmeth_android.h"
+
+#define BCB_FIELD_COMMAND_SZ 32
+#define BCB_PART_NAME "misc"
+#define BOOT_PART_NAME "boot"
+#define VENDOR_BOOT_PART_NAME "vendor_boot"
+
+/**
+ * struct android_priv - Private data
+ *
+ * This is read from the disk and recorded for use when the full Android
+ * kernel must be loaded and booted
+ */
+struct android_priv {
+	int boot_mode;
+	char slot[2];
+	u32 header_version;
+};
+
+static int android_check(struct udevice *dev, struct bootflow_iter *iter)
+{
+	/* This only works on mmc devices */
+	if (bootflow_iter_check_mmc(iter))
+		return log_msg_ret("mmc", -ENOTSUPP);
+
+	/* This only works on whole devices, as multiple
+	 * partitions are needed to boot Android
+	 */
+	if (iter->part != 0)
+		return log_msg_ret("mmc part", -ENOTSUPP);
+
+	return 0;
+}
+
+static int scan_boot_part(struct udevice *blk, struct android_priv *priv)
+{
+	struct blk_desc *desc = dev_get_uclass_plat(blk);
+	struct disk_partition partition;
+	char partname[PART_NAME_LEN];
+	ulong num_blks, bufsz;
+	char *buf;
+	int ret;
+
+	sprintf(partname, BOOT_PART_NAME "_%s", priv->slot);
+	ret = part_get_info_by_name(desc, partname, &partition);
+	if (ret < 0)
+		return log_msg_ret("part info", ret);
+
+	num_blks = DIV_ROUND_UP(sizeof(struct andr_boot_img_hdr_v0), desc->blksz);
+	bufsz = num_blks * desc->blksz;
+	buf = malloc(bufsz);
+	if (!buf)
+		return log_msg_ret("buf", -ENOMEM);
+
+	ret = blk_read(blk, partition.start, num_blks, buf);
+	if (ret != num_blks) {
+		free(buf);
+		return log_msg_ret("part read", -EIO);
+	}
+
+	if (!is_android_boot_image_header(buf)) {
+		free(buf);
+		return log_msg_ret("header", -ENOENT);
+	}
+
+	priv->header_version = android_image_get_version(buf);
+
+	return 0;
+}
+
+static int scan_vendor_boot_part(struct udevice *blk, const char slot[2])
+{
+	struct blk_desc *desc = dev_get_uclass_plat(blk);
+	struct disk_partition partition;
+	char partname[PART_NAME_LEN];
+	ulong num_blks, bufsz;
+	char *buf;
+	int ret;
+
+	sprintf(partname, VENDOR_BOOT_PART_NAME "_%s", slot);
+	ret = part_get_info_by_name(desc, partname, &partition);
+	if (ret < 0)
+		return log_msg_ret("part info", ret);
+
+	num_blks = DIV_ROUND_UP(sizeof(struct andr_vnd_boot_img_hdr), desc->blksz);
+	bufsz = num_blks * desc->blksz;
+	buf = malloc(bufsz);
+	if (!buf)
+		return log_msg_ret("buf", -ENOMEM);
+
+	ret = blk_read(blk, partition.start, num_blks, buf);
+	if (ret != num_blks) {
+		free(buf);
+		return log_msg_ret("part read", -EIO);
+	}
+
+	if (!is_android_vendor_boot_image_header(buf)) {
+		free(buf);
+		return log_msg_ret("header", -ENOENT);
+	}
+
+	return 0;
+}
+
+static int android_read_slot_from_bcb(struct bootflow *bflow, bool decrement)
+{
+	struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
+	struct android_priv *priv = bflow->bootmeth_priv;
+	struct disk_partition misc;
+	char slot_suffix[3];
+	int ret;
+
+	ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
+	if (ret < 0)
+		return log_msg_ret("part", ret);
+
+	ret = ab_select_slot(desc, &misc, decrement);
+	if (ret < 0)
+		return log_msg_ret("slot", ret);
+
+	priv->slot[0] = BOOT_SLOT_NAME(ret);
+	priv->slot[1] = '\0';
+
+	sprintf(slot_suffix, "_%s", priv->slot);
+	ret = bootflow_cmdline_set_arg(bflow, "androidboot.slot_suffix",
+				       slot_suffix, false);
+	if (ret < 0)
+		return log_msg_ret("slot", ret);
+
+	return 0;
+}
+
+static int configure_serialno(struct bootflow *bflow)
+{
+	char *serialno = env_get("serial#");
+
+	if (!serialno)
+		return log_msg_ret("serial", -ENOENT);
+
+	return bootflow_cmdline_set_arg(bflow, "androidboot.serialno", serialno, false);
+}
+
+static int android_read_bootflow(struct udevice *dev, struct bootflow *bflow)
+{
+	struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
+	struct disk_partition misc;
+	struct android_priv *priv;
+	char command[BCB_FIELD_COMMAND_SZ];
+	int ret;
+
+	bflow->state = BOOTFLOWST_MEDIA;
+
+	/* bcb_find_partition_and_load() will print errors to stdout
+	 * if BCB_PART_NAME is not found. To avoid that, check if the
+	 * partition exists first.
+	 */
+	ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
+	if (ret < 0)
+		return log_msg_ret("part", ret);
+
+	ret = bcb_find_partition_and_load("mmc", desc->devnum, BCB_PART_NAME);
+	if (ret < 0)
+		return log_msg_ret("bcb load", ret);
+
+	ret = bcb_get(BCB_FIELD_COMMAND, command, sizeof(command));
+	if (ret < 0)
+		return log_msg_ret("bcb read", ret);
+
+	priv = malloc(sizeof(struct android_priv));
+	if (!priv)
+		return log_msg_ret("buf", -ENOMEM);
+
+	bflow->bootmeth_priv = priv;
+	if (!strcmp("bootonce-bootloader", command)) {
+		priv->boot_mode = ANDROID_BOOT_MODE_BOOTLOADER;
+		bflow->os_name = strdup("Android (bootloader)");
+	} else if (!strcmp("boot-fastboot", command)) {
+		priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
+		bflow->os_name = strdup("Android (fastbootd)");
+	} else if (!strcmp("boot-recovery", command)) {
+		priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
+		bflow->os_name = strdup("Android (recovery)");
+	} else {
+		priv->boot_mode = ANDROID_BOOT_MODE_NORMAL;
+		bflow->os_name = strdup("Android");
+	}
+	if (!bflow->os_name)
+		return log_msg_ret("os", -ENOMEM);
+
+	if (priv->boot_mode == ANDROID_BOOT_MODE_BOOTLOADER) {
+		/* Clear BCB */
+		memset(command, 0, sizeof(command));
+		ret = bcb_set(BCB_FIELD_COMMAND, command);
+		if (ret < 0) {
+			free(priv);
+			return log_msg_ret("bcb set", ret);
+		}
+		ret = bcb_store();
+		if (ret < 0) {
+			free(priv);
+			return log_msg_ret("bcb store", ret);
+		}
+
+		bflow->state = BOOTFLOWST_READY;
+		return 0;
+	}
+
+	/* For recovery and normal boot, we need to scan the partitions */
+	ret = android_read_slot_from_bcb(bflow, false);
+	if (ret < 0) {
+		free(priv);
+		return log_msg_ret("read slot", ret);
+	}
+
+	ret = scan_boot_part(bflow->blk, priv);
+	if (ret < 0) {
+		printf("- scan boot failed: err=%d\n", ret);
+		free(priv);
+		return log_msg_ret("scan boot", ret);
+	}
+
+	if (priv->header_version != 4) {
+		printf("- Only boot.img v4 is supported\n");
+		free(priv);
+		return log_msg_ret("version", -EINVAL);
+	}
+
+	ret = scan_vendor_boot_part(bflow->blk, priv->slot);
+	if (ret < 0) {
+		printf("- scan vendor_boot failed: err=%d\n", ret);
+		free(priv);
+		return log_msg_ret("scan vendor_boot", ret);
+	}
+
+	/* Ignoring return code: setting serial number is not mandatory for booting */
+	configure_serialno(bflow);
+
+	if (priv->boot_mode == ANDROID_BOOT_MODE_NORMAL) {
+		ret = bootflow_cmdline_set_arg(bflow, "androidboot.force_normal_boot", "1", false);
+		if (ret < 0) {
+			free(priv);
+			return log_msg_ret("normal_boot", ret);
+		}
+	}
+
+	bflow->state = BOOTFLOWST_READY;
+
+	return 0;
+}
+
+static int android_read_file(struct udevice *dev, struct bootflow *bflow,
+			     const char *file_path, ulong addr, ulong *sizep)
+{
+	/* Reading individual files is not supported since we only
+	 * operate on whole mmc devices (because we require multiple partitions)
+	 */
+	return log_msg_ret("Unsupported", -ENOSYS);
+}
+
+static int read_slotted_partition(struct blk_desc *desc, const char *const name,
+				  const char slot[2], ulong addr)
+{
+	struct disk_partition partition;
+	char partname[PART_NAME_LEN];
+	int ret;
+	u32 n;
+
+	/* Ensure name fits in partname it should be: <name>_<slot>\0 */
+	if (strlen(name) > (PART_NAME_LEN - 2 - 1))
+		return log_msg_ret("name too long", -EINVAL);
+
+	sprintf(partname, "%s_%s", name, slot);
+	ret = part_get_info_by_name(desc, partname, &partition);
+	if (ret < 0)
+		return log_msg_ret("part", ret);
+
+	n = blk_dread(desc, partition.start, partition.size, map_sysmem(addr, 0));
+	if (n < partition.size)
+		return log_msg_ret("part read", -EIO);
+
+	return 0;
+}
+
+#if CONFIG_IS_ENABLED(AVB_VERIFY)
+static int avb_append_commandline_arg(struct bootflow *bflow, char *arg)
+{
+	char *key = strsep(&arg, "=");
+	char *value = arg;
+	int ret;
+
+	ret = bootflow_cmdline_set_arg(bflow, key, value, false);
+	if (ret < 0)
+		return log_msg_ret("avb cmdline", ret);
+
+	return 0;
+}
+
+static int avb_append_commandline(struct bootflow *bflow, char *cmdline)
+{
+	char *arg = strsep(&cmdline, " ");
+	int ret;
+
+	while (arg) {
+		ret = avb_append_commandline_arg(bflow, arg);
+		if (ret < 0)
+			return ret;
+
+		arg = strsep(&cmdline, " ");
+	}
+
+	return 0;
+}
+
+static int run_avb_verification(struct bootflow *bflow)
+{
+	struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
+	struct android_priv *priv = bflow->bootmeth_priv;
+	const char * const requested_partitions[] = {"boot", "vendor_boot"};
+	struct AvbOps *avb_ops;
+	AvbSlotVerifyResult result;
+	AvbSlotVerifyData *out_data;
+	enum avb_boot_state boot_state;
+	char *extra_args;
+	char slot_suffix[3];
+	bool unlocked = false;
+	int ret;
+
+	avb_ops = avb_ops_alloc(desc->devnum);
+	if (!avb_ops)
+		return log_msg_ret("avb ops", -ENOMEM);
+
+	sprintf(slot_suffix, "_%s", priv->slot);
+
+	ret = avb_ops->read_is_device_unlocked(avb_ops, &unlocked);
+	if (ret != AVB_IO_RESULT_OK)
+		return log_msg_ret("avb lock", -EIO);
+
+	result = avb_slot_verify(avb_ops,
+				 requested_partitions,
+				 slot_suffix,
+				 unlocked,
+				 AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
+				 &out_data);
+
+	if (result != AVB_SLOT_VERIFY_RESULT_OK) {
+		printf("Verification failed, reason: %s\n",
+		       str_avb_slot_error(result));
+		return log_msg_ret("avb verify", -EIO);
+	}
+
+	if (unlocked)
+		boot_state = AVB_ORANGE;
+	else
+		boot_state = AVB_GREEN;
+
+	extra_args = avb_set_state(avb_ops, boot_state);
+	if (extra_args) {
+		ret = avb_append_commandline_arg(bflow, extra_args);
+		if (ret < 0)
+			goto free_out_data;
+	}
+
+	ret = avb_append_commandline(bflow, out_data->cmdline);
+	if (ret < 0)
+		goto free_out_data;
+
+	return 0;
+
+ free_out_data:
+	if (out_data)
+		avb_slot_verify_data_free(out_data);
+
+	return log_msg_ret("avb cmdline", ret);
+}
+#else
+static int run_avb_verification(struct bootflow *bflow)
+{
+	int ret;
+
+	/* When AVB is unsupported, pass ORANGE state  */
+	ret = bootflow_cmdline_set_arg(bflow,
+				       "androidboot.verifiedbootstate",
+				       "orange", false);
+	if (ret < 0)
+		return log_msg_ret("avb cmdline", ret);
+
+	return 0;
+}
+#endif /* AVB_VERIFY */
+
+static int boot_android_normal(struct bootflow *bflow)
+{
+	struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
+	struct android_priv *priv = bflow->bootmeth_priv;
+	int ret;
+
+	ulong loadaddr = env_get_hex("loadaddr", 0);
+	ulong vloadaddr = env_get_hex("vendor_boot_comp_addr_r", 0);
+
+	ret = run_avb_verification(bflow);
+	if (ret < 0)
+		return log_msg_ret("avb", ret);
+
+	/* Read slot once more to decrement counter from BCB */
+	ret = android_read_slot_from_bcb(bflow, true);
+	if (ret < 0)
+		return log_msg_ret("read slot", ret);
+
+	ret = read_slotted_partition(desc, "boot", priv->slot, loadaddr);
+	if (ret < 0)
+		return log_msg_ret("read boot", ret);
+
+	ret = read_slotted_partition(desc, "vendor_boot", priv->slot, vloadaddr);
+	if (ret < 0)
+		return log_msg_ret("read vendor_boot", ret);
+
+	set_abootimg_addr(loadaddr);
+	set_avendor_bootimg_addr(vloadaddr);
+
+	ret = bootm_boot_start(loadaddr, bflow->cmdline);
+
+	return log_msg_ret("boot", ret);
+}
+
+static int boot_android_recovery(struct bootflow *bflow)
+{
+	int ret;
+
+	ret = boot_android_normal(bflow);
+
+	return log_msg_ret("boot", ret);
+}
+
+static int boot_android_bootloader(struct bootflow *bflow)
+{
+	int ret;
+
+	ret = run_command("fastboot usb 0", 0);
+	do_reset(NULL, 0, 0, NULL);
+
+	return log_msg_ret("boot", ret);
+}
+
+static int android_boot(struct udevice *dev, struct bootflow *bflow)
+{
+	struct android_priv *priv = bflow->bootmeth_priv;
+	int ret;
+
+	switch (priv->boot_mode) {
+	case ANDROID_BOOT_MODE_NORMAL:
+		ret = boot_android_normal(bflow);
+		break;
+	case ANDROID_BOOT_MODE_RECOVERY:
+		ret = boot_android_recovery(bflow);
+		break;
+	case ANDROID_BOOT_MODE_BOOTLOADER:
+		ret = boot_android_bootloader(bflow);
+		break;
+	default:
+		printf("ANDROID: Unknown boot mode %d. Running fastboot...\n",
+		       priv->boot_mode);
+		boot_android_bootloader(bflow);
+		/* Tell we failed to boot since boot mode is unknown */
+		ret = -EFAULT;
+	}
+
+	return ret;
+}
+
+static int android_bootmeth_bind(struct udevice *dev)
+{
+	struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
+
+	plat->desc = "Android boot";
+	plat->flags = BOOTMETHF_ANY_PART;
+
+	return 0;
+}
+
+static struct bootmeth_ops android_bootmeth_ops = {
+	.check		= android_check,
+	.read_bootflow	= android_read_bootflow,
+	.read_file	= android_read_file,
+	.boot		= android_boot,
+};
+
+static const struct udevice_id android_bootmeth_ids[] = {
+	{ .compatible = "u-boot,android" },
+	{ }
+};
+
+U_BOOT_DRIVER(bootmeth_android) = {
+	.name		= "bootmeth_android",
+	.id		= UCLASS_BOOTMETH,
+	.of_match	= android_bootmeth_ids,
+	.ops		= &android_bootmeth_ops,
+	.bind		= android_bootmeth_bind,
+};
diff --git a/boot/bootmeth_android.h b/boot/bootmeth_android.h
new file mode 100644
index 000000000000..411c2f2d15e7
--- /dev/null
+++ b/boot/bootmeth_android.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Bootmethod for Android
+ *
+ * Copyright (C) 2024 BayLibre, SAS
+ * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
+ */
+
+enum android_boot_mode {
+	ANDROID_BOOT_MODE_NORMAL = 0,
+
+	/* Android "recovery" is a special boot mode that uses another ramdisk.
+	 * It can be used to "factory reset" a board or to flash logical partitions
+	 * It operates in 2 modes: adb or fastbootd
+	 * To enter recovery from Android, we can do:
+	 * $ adb reboot recovery
+	 * $ adb reboot fastboot
+	 */
+	ANDROID_BOOT_MODE_RECOVERY,
+
+	/* Android "bootloader" is for accessing/reflashing physical partitions
+	 * Typically, this will launch a fastboot process in U-Boot.
+	 * To enter "bootloader" from Android, we can do:
+	 * $ adb reboot bootloader
+	 */
+	ANDROID_BOOT_MODE_BOOTLOADER,
+};
diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst
index a07a72581e7a..709fa9e64ff3 100644
--- a/doc/develop/bootstd.rst
+++ b/doc/develop/bootstd.rst
@@ -95,6 +95,7 @@ bootflows.
 
 Note: it is possible to have a bootmeth that uses a partition or a whole device
 directly, but it is more common to use a filesystem.
+For example, the Android bootmeth uses a whole device.
 
 Note that some bootmeths are 'global', meaning that they select the bootdev
 themselves. Examples include VBE and EFI boot manager. In this case, they
@@ -277,6 +278,9 @@ script_offset_f
 script_size_f
     Size of the script to load, e.g. 0x2000
 
+vendor_boot_comp_addr_r
+    Address to which to load the vendor_boot Android image, e.g. 0xe0000000
+
 Some variables are set by script bootmeth:
 
 devtype
@@ -418,6 +422,7 @@ Bootmeth drivers are provided for:
    - EFI boot using bootefi from disk
    - VBE
    - EFI boot using boot manager
+   - Android bootflow (boot image v4)
 
 
 Command interface
@@ -786,6 +791,7 @@ To do
 Some things that need to be done to completely replace the distro-boot scripts:
 
 - implement extensions (devicetree overlays with add-on boards)
+- implement legacy (boot image v2) android boot flow
 
 Other ideas:
 

-- 
2.45.0

[PATCH 6/6] bootstd: Add test for bootmeth_android

[Mattijs Korpershoek]

Add a unit test for testing the Android bootmethod.

This requires another mmc image (mmc7) to contain the following partitions:
- misc: contains the Bootloader Control Block (BCB)
- boot_a: contains a fake generic kernel image
- vendor_boot_a: contains a fake vendor_boot image

Also add BOOTMETH_ANDROID as a dependency on sandbox so that we can test
this with:

$ ./test/py/test.py --bd sandbox --build -k test_ut # to build the mmc7.img
$ ./test/py/test.py --bd sandbox --build -k bootflow_android

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 arch/sandbox/dts/test.dts |  8 +++++
 configs/sandbox_defconfig |  2 +-
 test/boot/bootflow.c      | 65 ++++++++++++++++++++++++++++++++++++++--
 test/py/tests/test_ut.py  | 76 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 147 insertions(+), 4 deletions(-)

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index a012f5c4c9ba..5fb5eac862ec 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -43,6 +43,7 @@
 		mmc4 = "/mmc4";
 		mmc5 = "/mmc5";
 		mmc6 = "/mmc6";
+		mmc7 = "/mmc7";
 		pci0 = &pci0;
 		pci1 = &pci1;
 		pci2 = &pci2;
@@ -1129,6 +1130,13 @@
 		filename = "mmc6.img";
 	};
 
+	/* This is used for Android tests */
+	mmc7 {
+		status = "disabled";
+		compatible = "sandbox,mmc";
+		filename = "mmc7.img";
+	};
+
 	pch {
 		compatible = "sandbox,pch";
 	};
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 93b52f2de5cf..bc4398f101a7 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -15,6 +15,7 @@ CONFIG_FIT=y
 CONFIG_FIT_RSASSA_PSS=y
 CONFIG_FIT_CIPHER=y
 CONFIG_FIT_VERBOSE=y
+CONFIG_BOOTMETH_ANDROID=y
 CONFIG_LEGACY_IMAGE_FORMAT=y
 CONFIG_MEASURED_BOOT=y
 CONFIG_BOOTSTAGE=y
@@ -40,7 +41,6 @@ CONFIG_LOG_MAX_LEVEL=9
 CONFIG_LOG_DEFAULT_LEVEL=6
 CONFIG_DISPLAY_BOARDINFO_LATE=y
 CONFIG_STACKPROTECTOR=y
-CONFIG_ANDROID_AB=y
 CONFIG_CMD_CPU=y
 CONFIG_CMD_LICENSE=y
 CONFIG_CMD_SMBIOS=y
diff --git a/test/boot/bootflow.c b/test/boot/bootflow.c
index 4511cfa7f9bf..934c4dcbad2b 100644
--- a/test/boot/bootflow.c
+++ b/test/boot/bootflow.c
@@ -27,6 +27,7 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+extern U_BOOT_DRIVER(bootmeth_android);
 extern U_BOOT_DRIVER(bootmeth_cros);
 extern U_BOOT_DRIVER(bootmeth_2script);
 
@@ -518,12 +519,12 @@ BOOTSTD_TEST(bootflow_cmd_boot, UT_TESTF_DM | UT_TESTF_SCAN_FDT);
  * @uts: Unit test state
  * @mmc_dev: MMC device to use, e.g. "mmc4". Note that this must remain valid
  *	in the caller until
- * @bind_cros: true to bind the ChromiumOS bootmeth
+ * @bind_cros: true to bind the ChromiumOS and Android bootmeths
  * @old_orderp: Returns the original bootdev order, which must be restored
  * Returns 0 on success, -ve on failure
  */
 static int prep_mmc_bootdev(struct unit_test_state *uts, const char *mmc_dev,
-			    bool bind_cros, const char ***old_orderp)
+			    bool bind_cros_android, const char ***old_orderp)
 {
 	static const char *order[] = {"mmc2", "mmc1", NULL, NULL};
 	struct udevice *dev, *bootstd;
@@ -545,12 +546,19 @@ static int prep_mmc_bootdev(struct unit_test_state *uts, const char *mmc_dev,
 				"bootmeth_script", 0, ofnode_null(), &dev));
 
 	/* Enable the cros bootmeth if needed */
-	if (IS_ENABLED(CONFIG_BOOTMETH_CROS) && bind_cros) {
+	if (IS_ENABLED(CONFIG_BOOTMETH_CROS) && bind_cros_android) {
 		ut_assertok(uclass_first_device_err(UCLASS_BOOTSTD, &bootstd));
 		ut_assertok(device_bind(bootstd, DM_DRIVER_REF(bootmeth_cros),
 					"cros", 0, ofnode_null(), &dev));
 	}
 
+	/* Enable the android bootmeths if needed */
+	if (IS_ENABLED(CONFIG_BOOTMETH_ANDROID) && bind_cros_android) {
+		ut_assertok(uclass_first_device_err(UCLASS_BOOTSTD, &bootstd));
+		ut_assertok(device_bind(bootstd, DM_DRIVER_REF(bootmeth_android),
+					"android", 0, ofnode_null(), &dev));
+	}
+
 	/* Change the order to include the device */
 	std = dev_get_priv(bootstd);
 	old_order = std->bootdev_order;
@@ -589,6 +597,37 @@ static int scan_mmc_bootdev(struct unit_test_state *uts, const char *mmc_dev,
 	return 0;
 }
 
+/**
+ * scan_mmc_android_bootdev() - Set up an mmc bootdev so we can access other
+ * distros. Android bootflow might print "ANDROID:*" while scanning
+ *
+ * @uts: Unit test state
+ * @mmc_dev: MMC device to use, e.g. "mmc4"
+ * Returns 0 on success, -ve on failure
+ */
+static int scan_mmc_android_bootdev(struct unit_test_state *uts, const char *mmc_dev)
+{
+	struct bootstd_priv *std;
+	struct udevice *bootstd;
+	const char **old_order;
+
+	ut_assertok(prep_mmc_bootdev(uts, mmc_dev, true, &old_order));
+
+	console_record_reset_enable();
+	ut_assertok(run_command("bootflow scan", 0));
+	/* Android bootflow might print one or two 'ANDROID:*' logs */
+	ut_check_skipline(uts);
+	ut_check_skipline(uts);
+	ut_assert_console_end();
+
+	/* Restore the order used by the device tree */
+	ut_assertok(uclass_first_device_err(UCLASS_BOOTSTD, &bootstd));
+	std = dev_get_priv(bootstd);
+	std->bootdev_order = old_order;
+
+	return 0;
+}
+
 /**
  * scan_mmc4_bootdev() - Set up the mmc4 bootdev so we can access a fake Armbian
  *
@@ -1160,3 +1199,23 @@ static int bootflow_cros(struct unit_test_state *uts)
 	return 0;
 }
 BOOTSTD_TEST(bootflow_cros, 0);
+
+/* Test Android bootmeth  */
+static int bootflow_android(struct unit_test_state *uts)
+{
+	ut_assertok(scan_mmc_android_bootdev(uts, "mmc7"));
+	ut_assertok(run_command("bootflow list", 0));
+
+	ut_assert_nextlinen("Showing all");
+	ut_assert_nextlinen("Seq");
+	ut_assert_nextlinen("---");
+	ut_assert_nextlinen("  0  extlinux");
+	ut_assert_nextlinen("  1  android      ready   mmc          0  mmc7.bootdev.whole        ");
+	ut_assert_nextlinen("---");
+	ut_assert_skip_to_line("(2 bootflows, 2 valid)");
+
+	ut_assert_console_end();
+
+	return 0;
+}
+BOOTSTD_TEST(bootflow_android, 0);
diff --git a/test/py/tests/test_ut.py b/test/py/tests/test_ut.py
index c169c835e38a..39e1abe02a68 100644
--- a/test/py/tests/test_ut.py
+++ b/test/py/tests/test_ut.py
@@ -423,6 +423,81 @@ def setup_cros_image(cons):
 
     return fname
 
+def setup_android_image(cons):
+    """Create a 20MB disk image with Android partitions"""
+    Partition = collections.namedtuple('part', 'start,size,name')
+    parts = {}
+    disk_data = None
+
+    def set_part_data(partnum, data):
+        """Set the contents of a disk partition
+
+        This updates disk_data by putting data in the right place
+
+        Args:
+            partnum (int): Partition number to set
+            data (bytes): Data for that partition
+        """
+        nonlocal disk_data
+
+        start = parts[partnum].start * sect_size
+        disk_data = disk_data[:start] + data + disk_data[start + len(data):]
+
+    mmc_dev = 7
+    fname = os.path.join(cons.config.source_dir, f'mmc{mmc_dev}.img')
+    u_boot_utils.run_and_log(cons, 'qemu-img create %s 20M' % fname)
+    u_boot_utils.run_and_log(cons, f'cgpt create {fname}')
+
+    ptr = 40
+
+    # Number of sectors in 1MB
+    sect_size = 512
+    sect_1mb = (1 << 20) // sect_size
+
+    required_parts = [
+        {'num': 1, 'label':'misc', 'size': '1M'},
+        {'num': 2, 'label':'boot_a', 'size': '4M'},
+        {'num': 3, 'label':'boot_b', 'size': '4M'},
+        {'num': 4, 'label':'vendor_boot_a', 'size': '4M'},
+        {'num': 5, 'label':'vendor_boot_b', 'size': '4M'},
+    ]
+
+    for part in required_parts:
+        size_str = part['size']
+        if 'M' in size_str:
+            size = int(size_str[:-1]) * sect_1mb
+        else:
+            size = int(size_str)
+        u_boot_utils.run_and_log(
+            cons,
+            f"cgpt add -i {part['num']} -b {ptr} -s {size} -l {part['label']} -t basicdata {fname}")
+        ptr += size
+
+    u_boot_utils.run_and_log(cons, f'cgpt boot -p {fname}')
+    out = u_boot_utils.run_and_log(cons, f'cgpt show -q {fname}')
+
+    # Create a dict (indexed by partition number) containing the above info
+    for line in out.splitlines():
+        start, size, num, name = line.split(maxsplit=3)
+        parts[int(num)] = Partition(int(start), int(size), name)
+
+    with open(fname, 'rb') as inf:
+        disk_data = inf.read()
+
+    boot_img = os.path.join(cons.config.result_dir, 'bootv4.img')
+    with open(boot_img, 'rb') as inf:
+        set_part_data(2, inf.read())
+
+    vendor_boot_img = os.path.join(cons.config.result_dir, 'vendor_boot.img')
+    with open(vendor_boot_img, 'rb') as inf:
+        set_part_data(4, inf.read())
+
+    with open(fname, 'wb') as outf:
+        outf.write(disk_data)
+
+    print('wrote to {}'.format(fname))
+
+    return fname
 
 def setup_cedit_file(cons):
     infname = os.path.join(cons.config.source_dir,
@@ -477,6 +552,7 @@ def test_ut_dm_init_bootstd(u_boot_console):
     setup_bootmenu_image(u_boot_console)
     setup_cedit_file(u_boot_console)
     setup_cros_image(u_boot_console)
+    setup_android_image(u_boot_console)
 
     # Restart so that the new mmc1.img is picked up
     u_boot_console.restart_uboot()

-- 
2.45.0

Re: [PATCH 1/6] boot: android: Provide vendor_bootimg_addr in boot_get_fdt()

[Igor Opaniuk]

On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
<mkorpershoek@baylibre.com> wrote:
>
> When calling android_image_get_dtb_by_index() using boot image v3+,
> we should also pass the vendor_boot ramdisk address.
>
> Use get_avendor_bootimg_addr() to do so.
>
> Note: on boot image v2, this is harmless since get_avendor_bootimg_addr()
> returns -1.
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> ---
>  boot/image-fdt.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/boot/image-fdt.c b/boot/image-fdt.c
> index 56dd7687f51c..8332792b8e80 100644
> --- a/boot/image-fdt.c
> +++ b/boot/image-fdt.c
> @@ -502,7 +502,7 @@ int boot_get_fdt(void *buf, const char *select, uint arch,
>                  * Firstly check if this android boot image has dtb field.
>                  */
>                 dtb_idx = (u32)env_get_ulong("adtb_idx", 10, 0);
> -               if (android_image_get_dtb_by_index((ulong)hdr, 0,
> +               if (android_image_get_dtb_by_index((ulong)hdr, get_avendor_bootimg_addr(),
>                                                    dtb_idx, &fdt_addr, &fdt_size)) {
>                         fdt_blob = (char *)map_sysmem(fdt_addr, 0);
>                         if (fdt_check_header(fdt_blob))
>
> --
> 2.45.0
>
Reviewed-by: Igor Opaniuk <igor.opaniuk@gmail.com>

-- 
Best regards - Atentamente - Meilleures salutations

Igor Opaniuk

mailto: igor.opaniuk@gmail.com
skype: igor.opanyuk
https://www.linkedin.com/in/iopaniuk

Re: [PATCH 2/6] boot: android: Add image_android_get_version()

[Igor Opaniuk]

Hi Mattijs,

On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
<mkorpershoek@baylibre.com> wrote:
>
> When reading a boot image header, we may need to retrieve the header
> version.
>
> Add a helper function for it.
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> ---
>  boot/image-android.c | 7 ++++++-
>  include/image.h      | 7 +++++++
>  2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/boot/image-android.c b/boot/image-android.c
> index ddd8ffd5e540..4f8fb51585eb 100644
> --- a/boot/image-android.c
> +++ b/boot/image-android.c
> @@ -185,7 +185,7 @@ bool android_image_get_data(const void *boot_hdr, const void *vendor_boot_hdr,
>                 return false;
>         }
>
> -       if (((struct andr_boot_img_hdr_v0 *)boot_hdr)->header_version > 2) {
> +       if (android_image_get_version(boot_hdr) > 2) {
>                 if (!vendor_boot_hdr) {
>                         printf("For boot header v3+ vendor boot image has to be provided\n");
>                         return false;
> @@ -203,6 +203,11 @@ bool android_image_get_data(const void *boot_hdr, const void *vendor_boot_hdr,
>         return true;
>  }
>
> +u32 android_image_get_version(const void *hdr)
> +{
> +       return ((struct andr_boot_img_hdr_v0 *)hdr)->header_version;
> +}
> +
>  static ulong android_image_get_kernel_addr(struct andr_image_data *img_data)
>  {
>         /*
> diff --git a/include/image.h b/include/image.h
> index acffd17e0dfd..18e5ced5ab42 100644
> --- a/include/image.h
> +++ b/include/image.h
> @@ -1963,6 +1963,13 @@ bool is_android_boot_image_header(const void *hdr);
>   */
>  bool is_android_vendor_boot_image_header(const void *vendor_boot_img);
>
> +/**
> + * android_image_get_version() - Retrieve the boot.img version
> + *
> + * Return: Android boot image header version.
> + */
> +u32 android_image_get_version(const void *hdr);
> +
>  /**
>   * get_abootimg_addr() - Get Android boot image address
>   *
>
> --
> 2.45.0
>
why introduce a helper function if there is only one user of it?

android_image_get_data() expects andr_boot_img_hdr_v0 anyway,
as it has an explicit check for it in the very beginning
(is_android_boot_image_header()).

Have you considered adjusting android_image_get_data() declaration, and just use
andr_boot_img_hdr_v0 *boot_hdr as first param instead (like it's done
for example in
android_boot_image_v0_v1_v2_parse_hdr()) and then rely on implicit
cast when this
function is used.

this is of course all a matter of preference, just thinking out loud

-- 
Best regards - Atentamente - Meilleures salutations

Igor Opaniuk

mailto: igor.opaniuk@gmail.com
skype: igor.opanyuk
https://www.linkedin.com/in/iopaniuk

Re: [PATCH 3/6] bootstd: Add bootflow_iter_check_mmc() helper

[Igor Opaniuk]

Hi Mattijs,

On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
<mkorpershoek@baylibre.com> wrote:
>
> Some bootflows might be able to only boot from MMC devices.
>
> Add a helper function these bootflows can use.
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> ---
>  boot/bootflow.c    | 12 ++++++++++++
>  include/bootflow.h |  9 +++++++++
>  2 files changed, 21 insertions(+)
>
> diff --git a/boot/bootflow.c b/boot/bootflow.c
> index 9aa3179c3881..59d77d2385f4 100644
> --- a/boot/bootflow.c
> +++ b/boot/bootflow.c
> @@ -575,6 +575,18 @@ int bootflow_iter_check_blk(const struct bootflow_iter *iter)
>         return -ENOTSUPP;
>  }
>
> +int bootflow_iter_check_mmc(const struct bootflow_iter *iter)
> +{
> +       const struct udevice *media = dev_get_parent(iter->dev);
> +       enum uclass_id id = device_get_uclass_id(media);
> +
> +       log_debug("uclass %d: %s\n", id, uclass_get_name(id));
> +       if (id == UCLASS_MMC)
> +               return 0;
> +
> +       return -ENOTSUPP;
> +}
> +
>  int bootflow_iter_check_sf(const struct bootflow_iter *iter)
>  {
>         const struct udevice *media = dev_get_parent(iter->dev);
> diff --git a/include/bootflow.h b/include/bootflow.h
> index 080ee8501225..6058ddd89b16 100644
> --- a/include/bootflow.h
> +++ b/include/bootflow.h
> @@ -407,6 +407,15 @@ void bootflow_remove(struct bootflow *bflow);
>   */
>  int bootflow_iter_check_blk(const struct bootflow_iter *iter);
>
> +/**
> + * bootflow_iter_check_mmc() - Check that a bootflow uses a MMC device
> + *
> + * This checks the bootdev in the bootflow to make sure it uses a mmc device
> + *
> + * Return: 0 if OK, -ENOTSUPP if some other device is used (e.g. ethernet)
> + */
> +int bootflow_iter_check_mmc(const struct bootflow_iter *iter);
> +
>  /**
>   * bootflow_iter_check_sf() - Check that a bootflow uses SPI FLASH
>   *
>
> --
> 2.45.0
>

Reviewed-by: Igor Opaniuk <igor.opaniuk@gmail.com>

A bit offtopic (just an idea for future refactoring), but I think all these
bootflow_iter_check_* helpers should be replaced by just one
int bootflow_iter_check_id(const struct bootflow_iter *iter, enum uclass_id id)
to avoid code duplication or at least keep all these
bootmedia-specific functions as
wrappers with one-line call to bootflow_iter_check_id(iter,
UCLASS_SPI_*) inside.

-- 
Best regards - Atentamente - Meilleures salutations

Igor Opaniuk

mailto: igor.opaniuk@gmail.com
skype: igor.opanyuk
https://www.linkedin.com/in/iopaniuk

Re: [PATCH 4/6] android: boot: Add set_abootimg_addr() and set_avendor_bootimg_addr()

[Igor Opaniuk]

On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
<mkorpershoek@baylibre.com> wrote:
>
> The only way to configure the load addresses for both bootimg and
> vendor_bootimg is by using the "abootimg" command.
> If we want to use the C API, there is no equivalent.
>
> Add set_abootimg_addr() and set_avendor_bootimg_addr() so that we can
> specify the load address from C.
>
> This can be useful for implementing an Android bootmethod.
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> ---
>  cmd/abootimg.c  | 10 ++++++++++
>  include/image.h | 14 ++++++++++++++
>  2 files changed, 24 insertions(+)
>
> diff --git a/cmd/abootimg.c b/cmd/abootimg.c
> index 88c77d999290..33381e22dec2 100644
> --- a/cmd/abootimg.c
> +++ b/cmd/abootimg.c
> @@ -21,11 +21,21 @@ ulong get_abootimg_addr(void)
>         return (_abootimg_addr == -1 ? image_load_addr : _abootimg_addr);
>  }
>
> +void set_abootimg_addr(ulong addr)
> +{
> +       _abootimg_addr = addr;
> +}
> +
>  ulong get_avendor_bootimg_addr(void)
>  {
>         return _avendor_bootimg_addr;
>  }
>
> +void set_avendor_bootimg_addr(ulong addr)
> +{
> +       _avendor_bootimg_addr = addr;
> +}
> +
>  static int abootimg_get_ver(int argc, char *const argv[])
>  {
>         const struct andr_boot_img_hdr_v0 *hdr;
> diff --git a/include/image.h b/include/image.h
> index 18e5ced5ab42..6deaf406605e 100644
> --- a/include/image.h
> +++ b/include/image.h
> @@ -1977,6 +1977,13 @@ u32 android_image_get_version(const void *hdr);
>   */
>  ulong get_abootimg_addr(void);
>
> +/**
> + * set_abootimg_addr() - Set Android boot image address
> + *
> + * Return: no returned results
> + */
> +void set_abootimg_addr(ulong addr);
> +
>  /**
>   * get_avendor_bootimg_addr() - Get Android vendor boot image address
>   *
> @@ -1984,6 +1991,13 @@ ulong get_abootimg_addr(void);
>   */
>  ulong get_avendor_bootimg_addr(void);
>
> +/**
> + * set_abootimg_addr() - Set Android vendor boot image address
> + *
> + * Return: no returned results
> + */
> +void set_avendor_bootimg_addr(ulong addr);
> +
>  /**
>   * board_fit_config_name_match() - Check for a matching board name
>   *
>
> --
> 2.45.0
>

Reviewed-by: Igor Opaniuk <igor.opaniuk@gmail.com>
-- 
Best regards - Atentamente - Meilleures salutations

Igor Opaniuk

mailto: igor.opaniuk@gmail.com
skype: igor.opanyuk
https://www.linkedin.com/in/iopaniuk

Re: [PATCH 5/6] bootstd: Add a bootmeth for Android

[Igor Opaniuk]

Hi Mattijs,

On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
<mkorpershoek@baylibre.com> wrote:
>
> Android boot flow is a bit different than a regular Linux distro.
> Android relies on multiple partitions in order to boot.
>
> A typical boot flow would be:
> 1. Parse the Bootloader Control Block (BCB, misc partition)
> 2. If BCB requested bootonce-bootloader, start fastboot and wait.
> 3. If BCB requested recovery or normal android, run the following:
> 3.a. Get slot (A/B) from BCB
> 3.b. Run AVB (Android Verified Boot) on boot partitions
> 3.c. Load boot and vendor_boot partitions
> 3.d. Load device-tree, ramdisk and boot
>
> The AOSP documentation has more details at [1], [2], [3]
>
> This has been implemented via complex boot scripts such as [4].
> However, these boot script are neither very maintainable nor generic.
> Moreover, DISTRO_DEFAULTS is being deprecated [5].
>
> Add a generic Android bootflow implementation for bootstd.
> For this initial version, only boot image v4 is supported.
>
> [1] https://source.android.com/docs/core/architecture/bootloader
> [2] https://source.android.com/docs/core/architecture/partitions
> [3] https://source.android.com/docs/core/architecture/partitions/generic-boot
> [4] https://source.denx.de/u-boot/u-boot/-/blob/master/include/configs/meson64_android.h
> [5] https://lore.kernel.org/r/all/20230914165615.1058529-17-sjg@chromium.org/
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> ---
>  MAINTAINERS             |   7 +
>  boot/Kconfig            |  14 ++
>  boot/Makefile           |   2 +
>  boot/bootmeth_android.c | 522 ++++++++++++++++++++++++++++++++++++++++++++++++
>  boot/bootmeth_android.h |  27 +++
>  doc/develop/bootstd.rst |   6 +
>  6 files changed, 578 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 66783d636e3d..6d2b87720565 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -939,6 +939,13 @@ F: include/bootstd.h
>  F:     net/eth_bootdevice.c
>  F:     test/boot/
>
> +BOOTMETH_ANDROID
> +M:     Mattijs Korpershoek <mkorpershoek@baylibre.com>
> +S:     Maintained
> +T:     git https://source.denx.de/u-boot/custodians/u-boot-dfu.git
> +F:     boot/bootmeth_android.c
> +F:     boot/bootmeth_android.h
> +
>  BTRFS
>  M:     Marek Behún <kabel@kernel.org>
>  R:     Qu Wenruo <wqu@suse.com>
> diff --git a/boot/Kconfig b/boot/Kconfig
> index 6f3096c15a6f..5fa6f3b8315d 100644
> --- a/boot/Kconfig
> +++ b/boot/Kconfig
> @@ -494,6 +494,20 @@ config BOOTMETH_GLOBAL
>           EFI bootmgr, since they take full control over which bootdevs are
>           selected to boot.
>
> +config BOOTMETH_ANDROID
> +       bool "Bootdev support for Android"
> +       depends on X86 || ARM || SANDBOX
> +       select ANDROID_AB
> +       select ANDROID_BOOT_IMAGE
> +       select CMD_BCB
> +       select PARTITION_TYPE_GUID
> +       select PARTITION_UUIDS
> +       help
> +         Enables support for booting Android using bootdevs. Android requires
> +         multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
> +
> +         Note that only MMC bootdevs are supported at present.
> +
>  config BOOTMETH_CROS
>         bool "Bootdev support for Chromium OS"
>         depends on X86 || ARM || SANDBOX
> diff --git a/boot/Makefile b/boot/Makefile
> index 84ccfeaecec4..75d1cd46fabf 100644
> --- a/boot/Makefile
> +++ b/boot/Makefile
> @@ -66,3 +66,5 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_REQUEST) += vbe_request.o
>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o
>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o
>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o
> +
> +obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_ANDROID) += bootmeth_android.o
> diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c
> new file mode 100644
> index 000000000000..26d548d2fd6e
> --- /dev/null
> +++ b/boot/bootmeth_android.c
> @@ -0,0 +1,522 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Bootmethod for Android
> + *
> + * Copyright (C) 2024 BayLibre, SAS
> + * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
> + */
> +#define LOG_CATEGORY UCLASS_BOOTSTD
> +
> +#include <android_ab.h>
> +#include <android_image.h>
> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
> +#include <avb_verify.h>
> +#endif
> +#include <bcb.h>
> +#include <blk.h>
> +#include <bootflow.h>
> +#include <bootm.h>
> +#include <bootmeth.h>
> +#include <dm.h>
> +#include <image.h>
> +#include <malloc.h>
> +#include <mapmem.h>
> +#include <part.h>
> +#include "bootmeth_android.h"
> +
> +#define BCB_FIELD_COMMAND_SZ 32
> +#define BCB_PART_NAME "misc"
> +#define BOOT_PART_NAME "boot"
> +#define VENDOR_BOOT_PART_NAME "vendor_boot"
> +
> +/**
> + * struct android_priv - Private data
> + *
> + * This is read from the disk and recorded for use when the full Android
> + * kernel must be loaded and booted
> + */
> +struct android_priv {
> +       int boot_mode;
> +       char slot[2];
> +       u32 header_version;
> +};
> +
> +static int android_check(struct udevice *dev, struct bootflow_iter *iter)
> +{
> +       /* This only works on mmc devices */
> +       if (bootflow_iter_check_mmc(iter))
> +               return log_msg_ret("mmc", -ENOTSUPP);
> +
> +       /* This only works on whole devices, as multiple
> +        * partitions are needed to boot Android
> +        */
Please use Linux kernel coding style for long comments [1].
Same in all occurrences below

[1] https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting
> +       if (iter->part != 0)
> +               return log_msg_ret("mmc part", -ENOTSUPP);
> +
> +       return 0;
> +}
> +
> +static int scan_boot_part(struct udevice *blk, struct android_priv *priv)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(blk);
> +       struct disk_partition partition;
> +       char partname[PART_NAME_LEN];
> +       ulong num_blks, bufsz;
> +       char *buf;
> +       int ret;
> +
> +       sprintf(partname, BOOT_PART_NAME "_%s", priv->slot);
> +       ret = part_get_info_by_name(desc, partname, &partition);
> +       if (ret < 0)
> +               return log_msg_ret("part info", ret);
> +
> +       num_blks = DIV_ROUND_UP(sizeof(struct andr_boot_img_hdr_v0), desc->blksz);
> +       bufsz = num_blks * desc->blksz;
> +       buf = malloc(bufsz);
> +       if (!buf)
> +               return log_msg_ret("buf", -ENOMEM);
> +
> +       ret = blk_read(blk, partition.start, num_blks, buf);
> +       if (ret != num_blks) {
> +               free(buf);
> +               return log_msg_ret("part read", -EIO);
> +       }
> +
> +       if (!is_android_boot_image_header(buf)) {
> +               free(buf);
> +               return log_msg_ret("header", -ENOENT);
> +       }
> +
> +       priv->header_version = android_image_get_version(buf);
> +
> +       return 0;
Shouldn't we free(buf) also here?

> +}
> +
> +static int scan_vendor_boot_part(struct udevice *blk, const char slot[2])
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(blk);
> +       struct disk_partition partition;
> +       char partname[PART_NAME_LEN];
> +       ulong num_blks, bufsz;
> +       char *buf;
> +       int ret;
> +
> +       sprintf(partname, VENDOR_BOOT_PART_NAME "_%s", slot);
> +       ret = part_get_info_by_name(desc, partname, &partition);
> +       if (ret < 0)
> +               return log_msg_ret("part info", ret);
> +
> +       num_blks = DIV_ROUND_UP(sizeof(struct andr_vnd_boot_img_hdr), desc->blksz);
> +       bufsz = num_blks * desc->blksz;
> +       buf = malloc(bufsz);
> +       if (!buf)
> +               return log_msg_ret("buf", -ENOMEM);
> +
> +       ret = blk_read(blk, partition.start, num_blks, buf);
> +       if (ret != num_blks) {
> +               free(buf);
> +               return log_msg_ret("part read", -EIO);
> +       }
> +
> +       if (!is_android_vendor_boot_image_header(buf)) {
> +               free(buf);
> +               return log_msg_ret("header", -ENOENT);
> +       }
> +
> +       return 0;
free(buf)?

> +}
> +
> +static int android_read_slot_from_bcb(struct bootflow *bflow, bool decrement)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
> +       struct android_priv *priv = bflow->bootmeth_priv;
> +       struct disk_partition misc;
> +       char slot_suffix[3];
> +       int ret;
> +
> +       ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
> +       if (ret < 0)
> +               return log_msg_ret("part", ret);
> +
> +       ret = ab_select_slot(desc, &misc, decrement);
> +       if (ret < 0)
> +               return log_msg_ret("slot", ret);
> +
> +       priv->slot[0] = BOOT_SLOT_NAME(ret);
> +       priv->slot[1] = '\0';
> +
> +       sprintf(slot_suffix, "_%s", priv->slot);
> +       ret = bootflow_cmdline_set_arg(bflow, "androidboot.slot_suffix",
> +                                      slot_suffix, false);
> +       if (ret < 0)
> +               return log_msg_ret("slot", ret);
> +
> +       return 0;
> +}
> +
> +static int configure_serialno(struct bootflow *bflow)
> +{
> +       char *serialno = env_get("serial#");
> +
> +       if (!serialno)
> +               return log_msg_ret("serial", -ENOENT);
> +
> +       return bootflow_cmdline_set_arg(bflow, "androidboot.serialno", serialno, false);
> +}
> +
> +static int android_read_bootflow(struct udevice *dev, struct bootflow *bflow)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
> +       struct disk_partition misc;
> +       struct android_priv *priv;
> +       char command[BCB_FIELD_COMMAND_SZ];
> +       int ret;
> +
> +       bflow->state = BOOTFLOWST_MEDIA;
> +
> +       /* bcb_find_partition_and_load() will print errors to stdout
> +        * if BCB_PART_NAME is not found. To avoid that, check if the
> +        * partition exists first.
> +        */
> +       ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
> +       if (ret < 0)
> +               return log_msg_ret("part", ret);
> +
> +       ret = bcb_find_partition_and_load("mmc", desc->devnum, BCB_PART_NAME);
> +       if (ret < 0)
> +               return log_msg_ret("bcb load", ret);
> +
> +       ret = bcb_get(BCB_FIELD_COMMAND, command, sizeof(command));
> +       if (ret < 0)
> +               return log_msg_ret("bcb read", ret);
> +
> +       priv = malloc(sizeof(struct android_priv));
> +       if (!priv)
> +               return log_msg_ret("buf", -ENOMEM);
> +
> +       bflow->bootmeth_priv = priv;
Probably we should do that just before successfully returning from the function,
otherwise we will end up with a dangling pointer.

> +       if (!strcmp("bootonce-bootloader", command)) {
> +               priv->boot_mode = ANDROID_BOOT_MODE_BOOTLOADER;
> +               bflow->os_name = strdup("Android (bootloader)");
> +       } else if (!strcmp("boot-fastboot", command)) {
> +               priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
> +               bflow->os_name = strdup("Android (fastbootd)");
> +       } else if (!strcmp("boot-recovery", command)) {
> +               priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
> +               bflow->os_name = strdup("Android (recovery)");
> +       } else {
> +               priv->boot_mode = ANDROID_BOOT_MODE_NORMAL;
> +               bflow->os_name = strdup("Android");
> +       }
> +       if (!bflow->os_name)
> +               return log_msg_ret("os", -ENOMEM);
> +
> +       if (priv->boot_mode == ANDROID_BOOT_MODE_BOOTLOADER) {
> +               /* Clear BCB */
> +               memset(command, 0, sizeof(command));
> +               ret = bcb_set(BCB_FIELD_COMMAND, command);
> +               if (ret < 0) {
> +                       free(priv);
> +                       return log_msg_ret("bcb set", ret);
> +               }
> +               ret = bcb_store();
> +               if (ret < 0) {
> +                       free(priv);

> +                       return log_msg_ret("bcb store", ret);
> +               }
> +
is free(bflow->bootmeth_priv) handled in functions that call
android_read_bootflow() ?

> +               bflow->state = BOOTFLOWST_READY;
> +               return 0;
> +       }
> +
> +       /* For recovery and normal boot, we need to scan the partitions */
> +       ret = android_read_slot_from_bcb(bflow, false);
> +       if (ret < 0) {
> +               free(priv);
> +               return log_msg_ret("read slot", ret);
> +       }
> +
> +       ret = scan_boot_part(bflow->blk, priv);
> +       if (ret < 0) {
> +               printf("- scan boot failed: err=%d\n", ret);
> +               free(priv);
> +               return log_msg_ret("scan boot", ret);
> +       }
> +
> +       if (priv->header_version != 4) {
> +               printf("- Only boot.img v4 is supported\n");
> +               free(priv);
> +               return log_msg_ret("version", -EINVAL);
> +       }
> +
> +       ret = scan_vendor_boot_part(bflow->blk, priv->slot);
> +       if (ret < 0) {
> +               printf("- scan vendor_boot failed: err=%d\n", ret);
> +               free(priv);
> +               return log_msg_ret("scan vendor_boot", ret);
> +       }
> +
> +       /* Ignoring return code: setting serial number is not mandatory for booting */
> +       configure_serialno(bflow);
> +
> +       if (priv->boot_mode == ANDROID_BOOT_MODE_NORMAL) {
> +               ret = bootflow_cmdline_set_arg(bflow, "androidboot.force_normal_boot", "1", false);
> +               if (ret < 0) {
> +                       free(priv);
> +                       return log_msg_ret("normal_boot", ret);
> +               }
> +       }
> +
> +       bflow->state = BOOTFLOWST_READY;
> +
> +       return 0;
> +}
> +
> +static int android_read_file(struct udevice *dev, struct bootflow *bflow,
> +                            const char *file_path, ulong addr, ulong *sizep)
> +{
> +       /* Reading individual files is not supported since we only
> +        * operate on whole mmc devices (because we require multiple partitions)
> +        */
> +       return log_msg_ret("Unsupported", -ENOSYS);
> +}
> +
> +static int read_slotted_partition(struct blk_desc *desc, const char *const name,
> +                                 const char slot[2], ulong addr)
> +{
> +       struct disk_partition partition;
> +       char partname[PART_NAME_LEN];
> +       int ret;
> +       u32 n;
> +
> +       /* Ensure name fits in partname it should be: <name>_<slot>\0 */
> +       if (strlen(name) > (PART_NAME_LEN - 2 - 1))
> +               return log_msg_ret("name too long", -EINVAL);
> +
> +       sprintf(partname, "%s_%s", name, slot);
> +       ret = part_get_info_by_name(desc, partname, &partition);
> +       if (ret < 0)
> +               return log_msg_ret("part", ret);
> +
> +       n = blk_dread(desc, partition.start, partition.size, map_sysmem(addr, 0));
> +       if (n < partition.size)
> +               return log_msg_ret("part read", -EIO);
> +
> +       return 0;
> +}
> +
> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
> +static int avb_append_commandline_arg(struct bootflow *bflow, char *arg)
> +{
> +       char *key = strsep(&arg, "=");
> +       char *value = arg;
> +       int ret;
> +
> +       ret = bootflow_cmdline_set_arg(bflow, key, value, false);
> +       if (ret < 0)
> +               return log_msg_ret("avb cmdline", ret);
> +
> +       return 0;
> +}
> +
> +static int avb_append_commandline(struct bootflow *bflow, char *cmdline)
> +{
> +       char *arg = strsep(&cmdline, " ");
> +       int ret;
> +
> +       while (arg) {
> +               ret = avb_append_commandline_arg(bflow, arg);
> +               if (ret < 0)
> +                       return ret;
> +
> +               arg = strsep(&cmdline, " ");
> +       }
> +
> +       return 0;
> +}
> +
> +static int run_avb_verification(struct bootflow *bflow)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
> +       struct android_priv *priv = bflow->bootmeth_priv;
> +       const char * const requested_partitions[] = {"boot", "vendor_boot"};
> +       struct AvbOps *avb_ops;
> +       AvbSlotVerifyResult result;
> +       AvbSlotVerifyData *out_data;
> +       enum avb_boot_state boot_state;
> +       char *extra_args;
> +       char slot_suffix[3];
> +       bool unlocked = false;
> +       int ret;
> +
> +       avb_ops = avb_ops_alloc(desc->devnum);
> +       if (!avb_ops)
> +               return log_msg_ret("avb ops", -ENOMEM);.
> +
> +       sprintf(slot_suffix, "_%s", priv->slot);
> +
> +       ret = avb_ops->read_is_device_unlocked(avb_ops, &unlocked);
> +       if (ret != AVB_IO_RESULT_OK)
> +               return log_msg_ret("avb lock", -EIO);
> +
> +       result = avb_slot_verify(avb_ops,
> +                                requested_partitions,
> +                                slot_suffix,
> +                                unlocked,
> +                                AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
> +                                &out_data);
> +
> +       if (result != AVB_SLOT_VERIFY_RESULT_OK) {
> +               printf("Verification failed, reason: %s\n",
> +                      str_avb_slot_error(result));
avb_ops_free(avb_ops) ?
> +               return log_msg_ret("avb verify", -EIO);
> +       }
> +
> +       if (unlocked)
> +               boot_state = AVB_ORANGE;
> +       else
> +               boot_state = AVB_GREEN;
> +
> +       extra_args = avb_set_state(avb_ops, boot_state);
> +       if (extra_args) {
> +               ret = avb_append_commandline_arg(bflow, extra_args);
> +               if (ret < 0)
> +                       goto free_out_data;
> +       }
> +
> +       ret = avb_append_commandline(bflow, out_data->cmdline);
> +       if (ret < 0)
> +               goto free_out_data;
> +
> +       return 0;
> +
> + free_out_data:
> +       if (out_data)
> +               avb_slot_verify_data_free(out_data);
> +
> +       return log_msg_ret("avb cmdline", ret);
> +}
> +#else
> +static int run_avb_verification(struct bootflow *bflow)
> +{
> +       int ret;
> +
> +       /* When AVB is unsupported, pass ORANGE state  */
> +       ret = bootflow_cmdline_set_arg(bflow,
> +                                      "androidboot.verifiedbootstate",
> +                                      "orange", false);
> +       if (ret < 0)
> +               return log_msg_ret("avb cmdline", ret);
> +
> +       return 0;
> +}
> +#endif /* AVB_VERIFY */
> +
> +static int boot_android_normal(struct bootflow *bflow)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
> +       struct android_priv *priv = bflow->bootmeth_priv;
> +       int ret;
> +
> +       ulong loadaddr = env_get_hex("loadaddr", 0);
> +       ulong vloadaddr = env_get_hex("vendor_boot_comp_addr_r", 0);
> +
> +       ret = run_avb_verification(bflow);
> +       if (ret < 0)
> +               return log_msg_ret("avb", ret);
> +
> +       /* Read slot once more to decrement counter from BCB */
> +       ret = android_read_slot_from_bcb(bflow, true);
> +       if (ret < 0)
> +               return log_msg_ret("read slot", ret);
> +
> +       ret = read_slotted_partition(desc, "boot", priv->slot, loadaddr);
> +       if (ret < 0)
> +               return log_msg_ret("read boot", ret);
> +
> +       ret = read_slotted_partition(desc, "vendor_boot", priv->slot, vloadaddr);
> +       if (ret < 0)
> +               return log_msg_ret("read vendor_boot", ret);
> +
> +       set_abootimg_addr(loadaddr);
> +       set_avendor_bootimg_addr(vloadaddr);
> +
> +       ret = bootm_boot_start(loadaddr, bflow->cmdline);
> +
> +       return log_msg_ret("boot", ret);
> +}
> +
> +static int boot_android_recovery(struct bootflow *bflow)
> +{
> +       int ret;
> +
> +       ret = boot_android_normal(bflow);
> +
> +       return log_msg_ret("boot", ret);
> +}
> +
> +static int boot_android_bootloader(struct bootflow *bflow)
> +{
> +       int ret;
> +
> +       ret = run_command("fastboot usb 0", 0);
select CMD_FASTBOOT in Kconfig (config BOOTMETH_ANDROID)?
> +       do_reset(NULL, 0, 0, NULL);
> +
> +       return log_msg_ret("boot", ret);
> +}
> +
> +static int android_boot(struct udevice *dev, struct bootflow *bflow)
> +{
> +       struct android_priv *priv = bflow->bootmeth_priv;
> +       int ret;
> +
> +       switch (priv->boot_mode) {
> +       case ANDROID_BOOT_MODE_NORMAL:
> +               ret = boot_android_normal(bflow);
> +               break;
> +       case ANDROID_BOOT_MODE_RECOVERY:
> +               ret = boot_android_recovery(bflow);
> +               break;
> +       case ANDROID_BOOT_MODE_BOOTLOADER:
> +               ret = boot_android_bootloader(bflow);
> +               break;
> +       default:
> +               printf("ANDROID: Unknown boot mode %d. Running fastboot...\n",
> +                      priv->boot_mode);
> +               boot_android_bootloader(bflow);
> +               /* Tell we failed to boot since boot mode is unknown */
> +               ret = -EFAULT;
> +       }
> +
> +       return ret;
> +}
> +
> +static int android_bootmeth_bind(struct udevice *dev)
> +{
> +       struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
> +
> +       plat->desc = "Android boot";
> +       plat->flags = BOOTMETHF_ANY_PART;
> +
> +       return 0;
> +}
> +
> +static struct bootmeth_ops android_bootmeth_ops = {
> +       .check          = android_check,
> +       .read_bootflow  = android_read_bootflow,
> +       .read_file      = android_read_file,
> +       .boot           = android_boot,
> +};
> +
> +static const struct udevice_id android_bootmeth_ids[] = {
> +       { .compatible = "u-boot,android" },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(bootmeth_android) = {
> +       .name           = "bootmeth_android",
> +       .id             = UCLASS_BOOTMETH,
> +       .of_match       = android_bootmeth_ids,
> +       .ops            = &android_bootmeth_ops,
> +       .bind           = android_bootmeth_bind,
> +};
> diff --git a/boot/bootmeth_android.h b/boot/bootmeth_android.h
> new file mode 100644
> index 000000000000..411c2f2d15e7
> --- /dev/null
> +++ b/boot/bootmeth_android.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Bootmethod for Android
> + *
> + * Copyright (C) 2024 BayLibre, SAS
> + * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
> + */
> +
> +enum android_boot_mode {
> +       ANDROID_BOOT_MODE_NORMAL = 0,
> +
> +       /* Android "recovery" is a special boot mode that uses another ramdisk.
> +        * It can be used to "factory reset" a board or to flash logical partitions
> +        * It operates in 2 modes: adb or fastbootd
> +        * To enter recovery from Android, we can do:
> +        * $ adb reboot recovery
> +        * $ adb reboot fastboot
> +        */
> +       ANDROID_BOOT_MODE_RECOVERY,
> +
> +       /* Android "bootloader" is for accessing/reflashing physical partitions
> +        * Typically, this will launch a fastboot process in U-Boot.
> +        * To enter "bootloader" from Android, we can do:
> +        * $ adb reboot bootloader
> +        */
> +       ANDROID_BOOT_MODE_BOOTLOADER,
> +};
> diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst
> index a07a72581e7a..709fa9e64ff3 100644
> --- a/doc/develop/bootstd.rst
> +++ b/doc/develop/bootstd.rst
> @@ -95,6 +95,7 @@ bootflows.
>
>  Note: it is possible to have a bootmeth that uses a partition or a whole device
>  directly, but it is more common to use a filesystem.
> +For example, the Android bootmeth uses a whole device.
>
>  Note that some bootmeths are 'global', meaning that they select the bootdev
>  themselves. Examples include VBE and EFI boot manager. In this case, they
> @@ -277,6 +278,9 @@ script_offset_f
>  script_size_f
>      Size of the script to load, e.g. 0x2000
>
> +vendor_boot_comp_addr_r
> +    Address to which to load the vendor_boot Android image, e.g. 0xe0000000
> +
>  Some variables are set by script bootmeth:
>
>  devtype
> @@ -418,6 +422,7 @@ Bootmeth drivers are provided for:
>     - EFI boot using bootefi from disk
>     - VBE
>     - EFI boot using boot manager
> +   - Android bootflow (boot image v4)
>
>
>  Command interface
> @@ -786,6 +791,7 @@ To do
>  Some things that need to be done to completely replace the distro-boot scripts:
>
>  - implement extensions (devicetree overlays with add-on boards)
> +- implement legacy (boot image v2) android boot flow
>
>  Other ideas:
>
>
> --
> 2.45.0
>

Some comments after a quick "scan". Will take a more detailed look a
bit later today/tomorrow.
-- 
Best regards - Atentamente - Meilleures salutations

Igor Opaniuk

mailto: igor.opaniuk@gmail.com
skype: igor.opanyuk
https://www.linkedin.com/in/iopaniuk

Re: [PATCH 2/6] boot: android: Add image_android_get_version()

[Mattijs Korpershoek]

Hi Igor,

Thank you for the review.

On lun., juin 10, 2024 at 11:20, Igor Opaniuk <igor.opaniuk@gmail.com> wrote:

> Hi Mattijs,
>
> On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
> <mkorpershoek@baylibre.com> wrote:
>>
>> When reading a boot image header, we may need to retrieve the header
>> version.
>>
>> Add a helper function for it.
>>
>> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> ---
>>  boot/image-android.c | 7 ++++++-
>>  include/image.h      | 7 +++++++
>>  2 files changed, 13 insertions(+), 1 deletion(-)
>>
>> diff --git a/boot/image-android.c b/boot/image-android.c
>> index ddd8ffd5e540..4f8fb51585eb 100644
>> --- a/boot/image-android.c
>> +++ b/boot/image-android.c
>> @@ -185,7 +185,7 @@ bool android_image_get_data(const void *boot_hdr, const void *vendor_boot_hdr,
>>                 return false;
>>         }
>>
>> -       if (((struct andr_boot_img_hdr_v0 *)boot_hdr)->header_version > 2) {
>> +       if (android_image_get_version(boot_hdr) > 2) {
>>                 if (!vendor_boot_hdr) {
>>                         printf("For boot header v3+ vendor boot image has to be provided\n");
>>                         return false;
>> @@ -203,6 +203,11 @@ bool android_image_get_data(const void *boot_hdr, const void *vendor_boot_hdr,
>>         return true;
>>  }
>>
>> +u32 android_image_get_version(const void *hdr)
>> +{
>> +       return ((struct andr_boot_img_hdr_v0 *)hdr)->header_version;
>> +}
>> +
>>  static ulong android_image_get_kernel_addr(struct andr_image_data *img_data)
>>  {
>>         /*
>> diff --git a/include/image.h b/include/image.h
>> index acffd17e0dfd..18e5ced5ab42 100644
>> --- a/include/image.h
>> +++ b/include/image.h
>> @@ -1963,6 +1963,13 @@ bool is_android_boot_image_header(const void *hdr);
>>   */
>>  bool is_android_vendor_boot_image_header(const void *vendor_boot_img);
>>
>> +/**
>> + * android_image_get_version() - Retrieve the boot.img version
>> + *
>> + * Return: Android boot image header version.
>> + */
>> +u32 android_image_get_version(const void *hdr);
>> +
>>  /**
>>   * get_abootimg_addr() - Get Android boot image address
>>   *
>>
>> --
>> 2.45.0
>>
> why introduce a helper function if there is only one user of it?

I added a second user of the helper function in patch 5/6.

>
> android_image_get_data() expects andr_boot_img_hdr_v0 anyway,
> as it has an explicit check for it in the very beginning
> (is_android_boot_image_header()).

Right.

>
> Have you considered adjusting android_image_get_data() declaration, and just use
> andr_boot_img_hdr_v0 *boot_hdr as first param instead (like it's done
> for example in
> android_boot_image_v0_v1_v2_parse_hdr()) and then rely on implicit
> cast when this
> function is used.
>
> this is of course all a matter of preference, just thinking out loud

I've given this some more thought, and since I'm already using
struct andr_boot_img_hdr_v0 in bootmeth_android/scan_boot_part(), I will
drop this patch for v2.

The helper seems indeed a bit useless given that we can use the struct's
member for this.

Thanks!

>
> -- 
> Best regards - Atentamente - Meilleures salutations
>
> Igor Opaniuk
>
> mailto: igor.opaniuk@gmail.com
> skype: igor.opanyuk
> https://www.linkedin.com/in/iopaniuk

Re: [PATCH 3/6] bootstd: Add bootflow_iter_check_mmc() helper

[Mattijs Korpershoek]

Hi Igor,

Thank you for the review.

On lun., juin 10, 2024 at 11:31, Igor Opaniuk <igor.opaniuk@gmail.com> wrote:

> Hi Mattijs,
>
> On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
> <mkorpershoek@baylibre.com> wrote:
>>
>> Some bootflows might be able to only boot from MMC devices.
>>
>> Add a helper function these bootflows can use.
>>
>> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> ---
>>  boot/bootflow.c    | 12 ++++++++++++
>>  include/bootflow.h |  9 +++++++++
>>  2 files changed, 21 insertions(+)
>>
>> diff --git a/boot/bootflow.c b/boot/bootflow.c
>> index 9aa3179c3881..59d77d2385f4 100644
>> --- a/boot/bootflow.c
>> +++ b/boot/bootflow.c
>> @@ -575,6 +575,18 @@ int bootflow_iter_check_blk(const struct bootflow_iter *iter)
>>         return -ENOTSUPP;
>>  }
>>
>> +int bootflow_iter_check_mmc(const struct bootflow_iter *iter)
>> +{
>> +       const struct udevice *media = dev_get_parent(iter->dev);
>> +       enum uclass_id id = device_get_uclass_id(media);
>> +
>> +       log_debug("uclass %d: %s\n", id, uclass_get_name(id));
>> +       if (id == UCLASS_MMC)
>> +               return 0;
>> +
>> +       return -ENOTSUPP;
>> +}
>> +
>>  int bootflow_iter_check_sf(const struct bootflow_iter *iter)
>>  {
>>         const struct udevice *media = dev_get_parent(iter->dev);
>> diff --git a/include/bootflow.h b/include/bootflow.h
>> index 080ee8501225..6058ddd89b16 100644
>> --- a/include/bootflow.h
>> +++ b/include/bootflow.h
>> @@ -407,6 +407,15 @@ void bootflow_remove(struct bootflow *bflow);
>>   */
>>  int bootflow_iter_check_blk(const struct bootflow_iter *iter);
>>
>> +/**
>> + * bootflow_iter_check_mmc() - Check that a bootflow uses a MMC device
>> + *
>> + * This checks the bootdev in the bootflow to make sure it uses a mmc device
>> + *
>> + * Return: 0 if OK, -ENOTSUPP if some other device is used (e.g. ethernet)
>> + */
>> +int bootflow_iter_check_mmc(const struct bootflow_iter *iter);
>> +
>>  /**
>>   * bootflow_iter_check_sf() - Check that a bootflow uses SPI FLASH
>>   *
>>
>> --
>> 2.45.0
>>
>
> Reviewed-by: Igor Opaniuk <igor.opaniuk@gmail.com>
>
> A bit offtopic (just an idea for future refactoring), but I think all these
> bootflow_iter_check_* helpers should be replaced by just one
> int bootflow_iter_check_id(const struct bootflow_iter *iter, enum uclass_id id)
> to avoid code duplication or at least keep all these
> bootmedia-specific functions as
> wrappers with one-line call to bootflow_iter_check_id(iter,
> UCLASS_SPI_*) inside.

I like this idea as well, I'll consider to implement this as a future refactoring.

>
> -- 
> Best regards - Atentamente - Meilleures salutations
>
> Igor Opaniuk
>
> mailto: igor.opaniuk@gmail.com
> skype: igor.opanyuk
> https://www.linkedin.com/in/iopaniuk

Re: [PATCH 5/6] bootstd: Add a bootmeth for Android

[Mattijs Korpershoek]

Hi Igor,

Thank you for your quick review.

On lun., juin 10, 2024 at 17:15, Igor Opaniuk <igor.opaniuk@gmail.com> wrote:

> Hi Mattijs,
>
> On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
> <mkorpershoek@baylibre.com> wrote:
>>
>> Android boot flow is a bit different than a regular Linux distro.
>> Android relies on multiple partitions in order to boot.
>>
>> A typical boot flow would be:
>> 1. Parse the Bootloader Control Block (BCB, misc partition)
>> 2. If BCB requested bootonce-bootloader, start fastboot and wait.
>> 3. If BCB requested recovery or normal android, run the following:
>> 3.a. Get slot (A/B) from BCB
>> 3.b. Run AVB (Android Verified Boot) on boot partitions
>> 3.c. Load boot and vendor_boot partitions
>> 3.d. Load device-tree, ramdisk and boot
>>
>> The AOSP documentation has more details at [1], [2], [3]
>>
>> This has been implemented via complex boot scripts such as [4].
>> However, these boot script are neither very maintainable nor generic.
>> Moreover, DISTRO_DEFAULTS is being deprecated [5].
>>
>> Add a generic Android bootflow implementation for bootstd.
>> For this initial version, only boot image v4 is supported.
>>
>> [1] https://source.android.com/docs/core/architecture/bootloader
>> [2] https://source.android.com/docs/core/architecture/partitions
>> [3] https://source.android.com/docs/core/architecture/partitions/generic-boot
>> [4] https://source.denx.de/u-boot/u-boot/-/blob/master/include/configs/meson64_android.h
>> [5] https://lore.kernel.org/r/all/20230914165615.1058529-17-sjg@chromium.org/
>>
>> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> ---
>>  MAINTAINERS             |   7 +
>>  boot/Kconfig            |  14 ++
>>  boot/Makefile           |   2 +
>>  boot/bootmeth_android.c | 522 ++++++++++++++++++++++++++++++++++++++++++++++++
>>  boot/bootmeth_android.h |  27 +++
>>  doc/develop/bootstd.rst |   6 +
>>  6 files changed, 578 insertions(+)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 66783d636e3d..6d2b87720565 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -939,6 +939,13 @@ F: include/bootstd.h
>>  F:     net/eth_bootdevice.c
>>  F:     test/boot/
>>
>> +BOOTMETH_ANDROID
>> +M:     Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> +S:     Maintained
>> +T:     git https://source.denx.de/u-boot/custodians/u-boot-dfu.git
>> +F:     boot/bootmeth_android.c
>> +F:     boot/bootmeth_android.h
>> +
>>  BTRFS
>>  M:     Marek Behún <kabel@kernel.org>
>>  R:     Qu Wenruo <wqu@suse.com>
>> diff --git a/boot/Kconfig b/boot/Kconfig
>> index 6f3096c15a6f..5fa6f3b8315d 100644
>> --- a/boot/Kconfig
>> +++ b/boot/Kconfig
>> @@ -494,6 +494,20 @@ config BOOTMETH_GLOBAL
>>           EFI bootmgr, since they take full control over which bootdevs are
>>           selected to boot.
>>
>> +config BOOTMETH_ANDROID
>> +       bool "Bootdev support for Android"
>> +       depends on X86 || ARM || SANDBOX
>> +       select ANDROID_AB
>> +       select ANDROID_BOOT_IMAGE
>> +       select CMD_BCB
>> +       select PARTITION_TYPE_GUID
>> +       select PARTITION_UUIDS
>> +       help
>> +         Enables support for booting Android using bootdevs. Android requires
>> +         multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
>> +
>> +         Note that only MMC bootdevs are supported at present.
>> +
>>  config BOOTMETH_CROS
>>         bool "Bootdev support for Chromium OS"
>>         depends on X86 || ARM || SANDBOX
>> diff --git a/boot/Makefile b/boot/Makefile
>> index 84ccfeaecec4..75d1cd46fabf 100644
>> --- a/boot/Makefile
>> +++ b/boot/Makefile
>> @@ -66,3 +66,5 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_REQUEST) += vbe_request.o
>>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o
>>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o
>>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o
>> +
>> +obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_ANDROID) += bootmeth_android.o
>> diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c
>> new file mode 100644
>> index 000000000000..26d548d2fd6e
>> --- /dev/null
>> +++ b/boot/bootmeth_android.c
>> @@ -0,0 +1,522 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Bootmethod for Android
>> + *
>> + * Copyright (C) 2024 BayLibre, SAS
>> + * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> + */
>> +#define LOG_CATEGORY UCLASS_BOOTSTD
>> +
>> +#include <android_ab.h>
>> +#include <android_image.h>
>> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
>> +#include <avb_verify.h>
>> +#endif
>> +#include <bcb.h>
>> +#include <blk.h>
>> +#include <bootflow.h>
>> +#include <bootm.h>
>> +#include <bootmeth.h>
>> +#include <dm.h>
>> +#include <image.h>
>> +#include <malloc.h>
>> +#include <mapmem.h>
>> +#include <part.h>
>> +#include "bootmeth_android.h"
>> +
>> +#define BCB_FIELD_COMMAND_SZ 32
>> +#define BCB_PART_NAME "misc"
>> +#define BOOT_PART_NAME "boot"
>> +#define VENDOR_BOOT_PART_NAME "vendor_boot"
>> +
>> +/**
>> + * struct android_priv - Private data
>> + *
>> + * This is read from the disk and recorded for use when the full Android
>> + * kernel must be loaded and booted
>> + */
>> +struct android_priv {
>> +       int boot_mode;
>> +       char slot[2];
>> +       u32 header_version;
>> +};
>> +
>> +static int android_check(struct udevice *dev, struct bootflow_iter *iter)
>> +{
>> +       /* This only works on mmc devices */
>> +       if (bootflow_iter_check_mmc(iter))
>> +               return log_msg_ret("mmc", -ENOTSUPP);
>> +
>> +       /* This only works on whole devices, as multiple
>> +        * partitions are needed to boot Android
>> +        */
> Please use Linux kernel coding style for long comments [1].
> Same in all occurrences below
>
> [1] https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting

Sorry about that that. Will do.
Odd that running checkpatch with --u-boot did not caught this.

$ ./scripts/checkpatch.pl --strict --u-boot --git HEAD^^..HEAD


>> +       if (iter->part != 0)
>> +               return log_msg_ret("mmc part", -ENOTSUPP);
>> +
>> +       return 0;
>> +}
>> +
>> +static int scan_boot_part(struct udevice *blk, struct android_priv *priv)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(blk);
>> +       struct disk_partition partition;
>> +       char partname[PART_NAME_LEN];
>> +       ulong num_blks, bufsz;
>> +       char *buf;
>> +       int ret;
>> +
>> +       sprintf(partname, BOOT_PART_NAME "_%s", priv->slot);
>> +       ret = part_get_info_by_name(desc, partname, &partition);
>> +       if (ret < 0)
>> +               return log_msg_ret("part info", ret);
>> +
>> +       num_blks = DIV_ROUND_UP(sizeof(struct andr_boot_img_hdr_v0), desc->blksz);
>> +       bufsz = num_blks * desc->blksz;
>> +       buf = malloc(bufsz);
>> +       if (!buf)
>> +               return log_msg_ret("buf", -ENOMEM);
>> +
>> +       ret = blk_read(blk, partition.start, num_blks, buf);
>> +       if (ret != num_blks) {
>> +               free(buf);
>> +               return log_msg_ret("part read", -EIO);
>> +       }
>> +
>> +       if (!is_android_boot_image_header(buf)) {
>> +               free(buf);
>> +               return log_msg_ret("header", -ENOENT);
>> +       }
>> +
>> +       priv->header_version = android_image_get_version(buf);
>> +
>> +       return 0;
> Shouldn't we free(buf) also here?

Yes we should. Will do for v2. Thanks for catching this!

>
>> +}
>> +
>> +static int scan_vendor_boot_part(struct udevice *blk, const char slot[2])
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(blk);
>> +       struct disk_partition partition;
>> +       char partname[PART_NAME_LEN];
>> +       ulong num_blks, bufsz;
>> +       char *buf;
>> +       int ret;
>> +
>> +       sprintf(partname, VENDOR_BOOT_PART_NAME "_%s", slot);
>> +       ret = part_get_info_by_name(desc, partname, &partition);
>> +       if (ret < 0)
>> +               return log_msg_ret("part info", ret);
>> +
>> +       num_blks = DIV_ROUND_UP(sizeof(struct andr_vnd_boot_img_hdr), desc->blksz);
>> +       bufsz = num_blks * desc->blksz;
>> +       buf = malloc(bufsz);
>> +       if (!buf)
>> +               return log_msg_ret("buf", -ENOMEM);
>> +
>> +       ret = blk_read(blk, partition.start, num_blks, buf);
>> +       if (ret != num_blks) {
>> +               free(buf);
>> +               return log_msg_ret("part read", -EIO);
>> +       }
>> +
>> +       if (!is_android_vendor_boot_image_header(buf)) {
>> +               free(buf);
>> +               return log_msg_ret("header", -ENOENT);
>> +       }
>> +
>> +       return 0;
> free(buf)?

Yes we should. Will do for v2. Thanks for catching this!

>
>> +}
>> +
>> +static int android_read_slot_from_bcb(struct bootflow *bflow, bool decrement)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> +       struct android_priv *priv = bflow->bootmeth_priv;
>> +       struct disk_partition misc;
>> +       char slot_suffix[3];
>> +       int ret;
>> +
>> +       ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
>> +       if (ret < 0)
>> +               return log_msg_ret("part", ret);
>> +
>> +       ret = ab_select_slot(desc, &misc, decrement);
>> +       if (ret < 0)
>> +               return log_msg_ret("slot", ret);
>> +
>> +       priv->slot[0] = BOOT_SLOT_NAME(ret);
>> +       priv->slot[1] = '\0';
>> +
>> +       sprintf(slot_suffix, "_%s", priv->slot);
>> +       ret = bootflow_cmdline_set_arg(bflow, "androidboot.slot_suffix",
>> +                                      slot_suffix, false);
>> +       if (ret < 0)
>> +               return log_msg_ret("slot", ret);
>> +
>> +       return 0;
>> +}
>> +
>> +static int configure_serialno(struct bootflow *bflow)
>> +{
>> +       char *serialno = env_get("serial#");
>> +
>> +       if (!serialno)
>> +               return log_msg_ret("serial", -ENOENT);
>> +
>> +       return bootflow_cmdline_set_arg(bflow, "androidboot.serialno", serialno, false);
>> +}
>> +
>> +static int android_read_bootflow(struct udevice *dev, struct bootflow *bflow)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> +       struct disk_partition misc;
>> +       struct android_priv *priv;
>> +       char command[BCB_FIELD_COMMAND_SZ];
>> +       int ret;
>> +
>> +       bflow->state = BOOTFLOWST_MEDIA;
>> +
>> +       /* bcb_find_partition_and_load() will print errors to stdout
>> +        * if BCB_PART_NAME is not found. To avoid that, check if the
>> +        * partition exists first.
>> +        */
>> +       ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
>> +       if (ret < 0)
>> +               return log_msg_ret("part", ret);
>> +
>> +       ret = bcb_find_partition_and_load("mmc", desc->devnum, BCB_PART_NAME);
>> +       if (ret < 0)
>> +               return log_msg_ret("bcb load", ret);
>> +
>> +       ret = bcb_get(BCB_FIELD_COMMAND, command, sizeof(command));
>> +       if (ret < 0)
>> +               return log_msg_ret("bcb read", ret);
>> +
>> +       priv = malloc(sizeof(struct android_priv));
>> +       if (!priv)
>> +               return log_msg_ret("buf", -ENOMEM);
>> +
>> +       bflow->bootmeth_priv = priv;
> Probably we should do that just before successfully returning from the function,
> otherwise we will end up with a dangling pointer.

Right, thanks for the suggestion. Will do for v2.

>
>> +       if (!strcmp("bootonce-bootloader", command)) {
>> +               priv->boot_mode = ANDROID_BOOT_MODE_BOOTLOADER;
>> +               bflow->os_name = strdup("Android (bootloader)");
>> +       } else if (!strcmp("boot-fastboot", command)) {
>> +               priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
>> +               bflow->os_name = strdup("Android (fastbootd)");
>> +       } else if (!strcmp("boot-recovery", command)) {
>> +               priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
>> +               bflow->os_name = strdup("Android (recovery)");
>> +       } else {
>> +               priv->boot_mode = ANDROID_BOOT_MODE_NORMAL;
>> +               bflow->os_name = strdup("Android");
>> +       }
>> +       if (!bflow->os_name)
>> +               return log_msg_ret("os", -ENOMEM);
>> +
>> +       if (priv->boot_mode == ANDROID_BOOT_MODE_BOOTLOADER) {
>> +               /* Clear BCB */
>> +               memset(command, 0, sizeof(command));
>> +               ret = bcb_set(BCB_FIELD_COMMAND, command);
>> +               if (ret < 0) {
>> +                       free(priv);
>> +                       return log_msg_ret("bcb set", ret);
>> +               }
>> +               ret = bcb_store();
>> +               if (ret < 0) {
>> +                       free(priv);
>
>> +                       return log_msg_ret("bcb store", ret);
>> +               }
>> +
> is free(bflow->bootmeth_priv) handled in functions that call
> android_read_bootflow() ?

It's not. Future functions (called later) like boot_android() need to
access this structure.

I've modeled this after bootmeth_cros/cros_boot() but I don't
see a reason for not freeing this just before calling bootm().
On the other hand, we will be booting an OS (and this quitting U-Boot)
so it's not entirely needed.

I don't have a strong opinion on this so I can add the free() in
boot_android_normal() and boot_android_bootloader().

>
>> +               bflow->state = BOOTFLOWST_READY;
>> +               return 0;
>> +       }
>> +
>> +       /* For recovery and normal boot, we need to scan the partitions */
>> +       ret = android_read_slot_from_bcb(bflow, false);
>> +       if (ret < 0) {
>> +               free(priv);
>> +               return log_msg_ret("read slot", ret);
>> +       }
>> +
>> +       ret = scan_boot_part(bflow->blk, priv);
>> +       if (ret < 0) {
>> +               printf("- scan boot failed: err=%d\n", ret);
>> +               free(priv);
>> +               return log_msg_ret("scan boot", ret);
>> +       }
>> +
>> +       if (priv->header_version != 4) {
>> +               printf("- Only boot.img v4 is supported\n");
>> +               free(priv);
>> +               return log_msg_ret("version", -EINVAL);
>> +       }
>> +
>> +       ret = scan_vendor_boot_part(bflow->blk, priv->slot);
>> +       if (ret < 0) {
>> +               printf("- scan vendor_boot failed: err=%d\n", ret);
>> +               free(priv);
>> +               return log_msg_ret("scan vendor_boot", ret);
>> +       }
>> +
>> +       /* Ignoring return code: setting serial number is not mandatory for booting */
>> +       configure_serialno(bflow);
>> +
>> +       if (priv->boot_mode == ANDROID_BOOT_MODE_NORMAL) {
>> +               ret = bootflow_cmdline_set_arg(bflow, "androidboot.force_normal_boot", "1", false);
>> +               if (ret < 0) {
>> +                       free(priv);
>> +                       return log_msg_ret("normal_boot", ret);
>> +               }
>> +       }
>> +
>> +       bflow->state = BOOTFLOWST_READY;
>> +
>> +       return 0;
>> +}
>> +
>> +static int android_read_file(struct udevice *dev, struct bootflow *bflow,
>> +                            const char *file_path, ulong addr, ulong *sizep)
>> +{
>> +       /* Reading individual files is not supported since we only
>> +        * operate on whole mmc devices (because we require multiple partitions)
>> +        */
>> +       return log_msg_ret("Unsupported", -ENOSYS);
>> +}
>> +
>> +static int read_slotted_partition(struct blk_desc *desc, const char *const name,
>> +                                 const char slot[2], ulong addr)
>> +{
>> +       struct disk_partition partition;
>> +       char partname[PART_NAME_LEN];
>> +       int ret;
>> +       u32 n;
>> +
>> +       /* Ensure name fits in partname it should be: <name>_<slot>\0 */
>> +       if (strlen(name) > (PART_NAME_LEN - 2 - 1))
>> +               return log_msg_ret("name too long", -EINVAL);
>> +
>> +       sprintf(partname, "%s_%s", name, slot);
>> +       ret = part_get_info_by_name(desc, partname, &partition);
>> +       if (ret < 0)
>> +               return log_msg_ret("part", ret);
>> +
>> +       n = blk_dread(desc, partition.start, partition.size, map_sysmem(addr, 0));
>> +       if (n < partition.size)
>> +               return log_msg_ret("part read", -EIO);
>> +
>> +       return 0;
>> +}
>> +
>> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
>> +static int avb_append_commandline_arg(struct bootflow *bflow, char *arg)
>> +{
>> +       char *key = strsep(&arg, "=");
>> +       char *value = arg;
>> +       int ret;
>> +
>> +       ret = bootflow_cmdline_set_arg(bflow, key, value, false);
>> +       if (ret < 0)
>> +               return log_msg_ret("avb cmdline", ret);
>> +
>> +       return 0;
>> +}
>> +
>> +static int avb_append_commandline(struct bootflow *bflow, char *cmdline)
>> +{
>> +       char *arg = strsep(&cmdline, " ");
>> +       int ret;
>> +
>> +       while (arg) {
>> +               ret = avb_append_commandline_arg(bflow, arg);
>> +               if (ret < 0)
>> +                       return ret;
>> +
>> +               arg = strsep(&cmdline, " ");
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int run_avb_verification(struct bootflow *bflow)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> +       struct android_priv *priv = bflow->bootmeth_priv;
>> +       const char * const requested_partitions[] = {"boot", "vendor_boot"};
>> +       struct AvbOps *avb_ops;
>> +       AvbSlotVerifyResult result;
>> +       AvbSlotVerifyData *out_data;
>> +       enum avb_boot_state boot_state;
>> +       char *extra_args;
>> +       char slot_suffix[3];
>> +       bool unlocked = false;
>> +       int ret;
>> +
>> +       avb_ops = avb_ops_alloc(desc->devnum);
>> +       if (!avb_ops)
>> +               return log_msg_ret("avb ops", -ENOMEM);.
>> +
>> +       sprintf(slot_suffix, "_%s", priv->slot);
>> +
>> +       ret = avb_ops->read_is_device_unlocked(avb_ops, &unlocked);
>> +       if (ret != AVB_IO_RESULT_OK)
>> +               return log_msg_ret("avb lock", -EIO);
>> +
>> +       result = avb_slot_verify(avb_ops,
>> +                                requested_partitions,
>> +                                slot_suffix,
>> +                                unlocked,
>> +                                AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
>> +                                &out_data);
>> +
>> +       if (result != AVB_SLOT_VERIFY_RESULT_OK) {
>> +               printf("Verification failed, reason: %s\n",
>> +                      str_avb_slot_error(result));
> avb_ops_free(avb_ops) ?

Yes we should. Will do for v2. Thanks for catching this!

>> +               return log_msg_ret("avb verify", -EIO);
>> +       }
>> +
>> +       if (unlocked)
>> +               boot_state = AVB_ORANGE;
>> +       else
>> +               boot_state = AVB_GREEN;
>> +
>> +       extra_args = avb_set_state(avb_ops, boot_state);
>> +       if (extra_args) {
>> +               ret = avb_append_commandline_arg(bflow, extra_args);
>> +               if (ret < 0)
>> +                       goto free_out_data;
>> +       }
>> +
>> +       ret = avb_append_commandline(bflow, out_data->cmdline);
>> +       if (ret < 0)
>> +               goto free_out_data;
>> +
>> +       return 0;
>> +
>> + free_out_data:
>> +       if (out_data)
>> +               avb_slot_verify_data_free(out_data);
>> +
>> +       return log_msg_ret("avb cmdline", ret);
>> +}
>> +#else
>> +static int run_avb_verification(struct bootflow *bflow)
>> +{
>> +       int ret;
>> +
>> +       /* When AVB is unsupported, pass ORANGE state  */
>> +       ret = bootflow_cmdline_set_arg(bflow,
>> +                                      "androidboot.verifiedbootstate",
>> +                                      "orange", false);
>> +       if (ret < 0)
>> +               return log_msg_ret("avb cmdline", ret);
>> +
>> +       return 0;
>> +}
>> +#endif /* AVB_VERIFY */
>> +
>> +static int boot_android_normal(struct bootflow *bflow)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> +       struct android_priv *priv = bflow->bootmeth_priv;
>> +       int ret;
>> +
>> +       ulong loadaddr = env_get_hex("loadaddr", 0);
>> +       ulong vloadaddr = env_get_hex("vendor_boot_comp_addr_r", 0);
>> +
>> +       ret = run_avb_verification(bflow);
>> +       if (ret < 0)
>> +               return log_msg_ret("avb", ret);
>> +
>> +       /* Read slot once more to decrement counter from BCB */
>> +       ret = android_read_slot_from_bcb(bflow, true);
>> +       if (ret < 0)
>> +               return log_msg_ret("read slot", ret);
>> +
>> +       ret = read_slotted_partition(desc, "boot", priv->slot, loadaddr);
>> +       if (ret < 0)
>> +               return log_msg_ret("read boot", ret);
>> +
>> +       ret = read_slotted_partition(desc, "vendor_boot", priv->slot, vloadaddr);
>> +       if (ret < 0)
>> +               return log_msg_ret("read vendor_boot", ret);
>> +
>> +       set_abootimg_addr(loadaddr);
>> +       set_avendor_bootimg_addr(vloadaddr);
>> +
>> +       ret = bootm_boot_start(loadaddr, bflow->cmdline);
>> +
>> +       return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int boot_android_recovery(struct bootflow *bflow)
>> +{
>> +       int ret;
>> +
>> +       ret = boot_android_normal(bflow);
>> +
>> +       return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int boot_android_bootloader(struct bootflow *bflow)
>> +{
>> +       int ret;
>> +
>> +       ret = run_command("fastboot usb 0", 0);
> select CMD_FASTBOOT in Kconfig (config BOOTMETH_ANDROID)?

Yes, I will add this for v2. Thank you for the suggestion.

>> +       do_reset(NULL, 0, 0, NULL);
>> +
>> +       return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int android_boot(struct udevice *dev, struct bootflow *bflow)
>> +{
>> +       struct android_priv *priv = bflow->bootmeth_priv;
>> +       int ret;
>> +
>> +       switch (priv->boot_mode) {
>> +       case ANDROID_BOOT_MODE_NORMAL:
>> +               ret = boot_android_normal(bflow);
>> +               break;
>> +       case ANDROID_BOOT_MODE_RECOVERY:
>> +               ret = boot_android_recovery(bflow);
>> +               break;
>> +       case ANDROID_BOOT_MODE_BOOTLOADER:
>> +               ret = boot_android_bootloader(bflow);
>> +               break;
>> +       default:
>> +               printf("ANDROID: Unknown boot mode %d. Running fastboot...\n",
>> +                      priv->boot_mode);
>> +               boot_android_bootloader(bflow);
>> +               /* Tell we failed to boot since boot mode is unknown */
>> +               ret = -EFAULT;
>> +       }
>> +
>> +       return ret;
>> +}
>> +
>> +static int android_bootmeth_bind(struct udevice *dev)
>> +{
>> +       struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
>> +
>> +       plat->desc = "Android boot";
>> +       plat->flags = BOOTMETHF_ANY_PART;
>> +
>> +       return 0;
>> +}
>> +
>> +static struct bootmeth_ops android_bootmeth_ops = {
>> +       .check          = android_check,
>> +       .read_bootflow  = android_read_bootflow,
>> +       .read_file      = android_read_file,
>> +       .boot           = android_boot,
>> +};
>> +
>> +static const struct udevice_id android_bootmeth_ids[] = {
>> +       { .compatible = "u-boot,android" },
>> +       { }
>> +};
>> +
>> +U_BOOT_DRIVER(bootmeth_android) = {
>> +       .name           = "bootmeth_android",
>> +       .id             = UCLASS_BOOTMETH,
>> +       .of_match       = android_bootmeth_ids,
>> +       .ops            = &android_bootmeth_ops,
>> +       .bind           = android_bootmeth_bind,
>> +};
>> diff --git a/boot/bootmeth_android.h b/boot/bootmeth_android.h
>> new file mode 100644
>> index 000000000000..411c2f2d15e7
>> --- /dev/null
>> +++ b/boot/bootmeth_android.h
>> @@ -0,0 +1,27 @@
>> +/* SPDX-License-Identifier: GPL-2.0+ */
>> +/*
>> + * Bootmethod for Android
>> + *
>> + * Copyright (C) 2024 BayLibre, SAS
>> + * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> + */
>> +
>> +enum android_boot_mode {
>> +       ANDROID_BOOT_MODE_NORMAL = 0,
>> +
>> +       /* Android "recovery" is a special boot mode that uses another ramdisk.
>> +        * It can be used to "factory reset" a board or to flash logical partitions
>> +        * It operates in 2 modes: adb or fastbootd
>> +        * To enter recovery from Android, we can do:
>> +        * $ adb reboot recovery
>> +        * $ adb reboot fastboot
>> +        */
>> +       ANDROID_BOOT_MODE_RECOVERY,
>> +
>> +       /* Android "bootloader" is for accessing/reflashing physical partitions
>> +        * Typically, this will launch a fastboot process in U-Boot.
>> +        * To enter "bootloader" from Android, we can do:
>> +        * $ adb reboot bootloader
>> +        */
>> +       ANDROID_BOOT_MODE_BOOTLOADER,
>> +};
>> diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst
>> index a07a72581e7a..709fa9e64ff3 100644
>> --- a/doc/develop/bootstd.rst
>> +++ b/doc/develop/bootstd.rst
>> @@ -95,6 +95,7 @@ bootflows.
>>
>>  Note: it is possible to have a bootmeth that uses a partition or a whole device
>>  directly, but it is more common to use a filesystem.
>> +For example, the Android bootmeth uses a whole device.
>>
>>  Note that some bootmeths are 'global', meaning that they select the bootdev
>>  themselves. Examples include VBE and EFI boot manager. In this case, they
>> @@ -277,6 +278,9 @@ script_offset_f
>>  script_size_f
>>      Size of the script to load, e.g. 0x2000
>>
>> +vendor_boot_comp_addr_r
>> +    Address to which to load the vendor_boot Android image, e.g. 0xe0000000
>> +
>>  Some variables are set by script bootmeth:
>>
>>  devtype
>> @@ -418,6 +422,7 @@ Bootmeth drivers are provided for:
>>     - EFI boot using bootefi from disk
>>     - VBE
>>     - EFI boot using boot manager
>> +   - Android bootflow (boot image v4)
>>
>>
>>  Command interface
>> @@ -786,6 +791,7 @@ To do
>>  Some things that need to be done to completely replace the distro-boot scripts:
>>
>>  - implement extensions (devicetree overlays with add-on boards)
>> +- implement legacy (boot image v2) android boot flow
>>
>>  Other ideas:
>>
>>
>> --
>> 2.45.0
>>
>
> Some comments after a quick "scan". Will take a more detailed look a
> bit later today/tomorrow.

Thanks a bunch for your quick scan. You caught quite some issues
already.
I will implement these suggestions and will be awaiting the detailed
look before sending a v2.

> -- 
> Best regards - Atentamente - Meilleures salutations
>
> Igor Opaniuk
>
> mailto: igor.opaniuk@gmail.com
> skype: igor.opanyuk
> https://www.linkedin.com/in/iopaniuk

Re: [PATCH 5/6] bootstd: Add a bootmeth for Android

[Simon Glass]

Hi Mattijs,

On Thu, 6 Jun 2024 at 06:24, Mattijs Korpershoek
<mkorpershoek@baylibre.com> wrote:
>
> Android boot flow is a bit different than a regular Linux distro.
> Android relies on multiple partitions in order to boot.
>
> A typical boot flow would be:
> 1. Parse the Bootloader Control Block (BCB, misc partition)
> 2. If BCB requested bootonce-bootloader, start fastboot and wait.
> 3. If BCB requested recovery or normal android, run the following:
> 3.a. Get slot (A/B) from BCB
> 3.b. Run AVB (Android Verified Boot) on boot partitions
> 3.c. Load boot and vendor_boot partitions
> 3.d. Load device-tree, ramdisk and boot
>
> The AOSP documentation has more details at [1], [2], [3]
>
> This has been implemented via complex boot scripts such as [4].
> However, these boot script are neither very maintainable nor generic.
> Moreover, DISTRO_DEFAULTS is being deprecated [5].
>
> Add a generic Android bootflow implementation for bootstd.
> For this initial version, only boot image v4 is supported.
>
> [1] https://source.android.com/docs/core/architecture/bootloader
> [2] https://source.android.com/docs/core/architecture/partitions
> [3] https://source.android.com/docs/core/architecture/partitions/generic-boot
> [4] https://source.denx.de/u-boot/u-boot/-/blob/master/include/configs/meson64_android.h
> [5] https://lore.kernel.org/r/all/20230914165615.1058529-17-sjg@chromium.org/
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> ---
>  MAINTAINERS             |   7 +
>  boot/Kconfig            |  14 ++
>  boot/Makefile           |   2 +
>  boot/bootmeth_android.c | 522 ++++++++++++++++++++++++++++++++++++++++++++++++
>  boot/bootmeth_android.h |  27 +++
>  doc/develop/bootstd.rst |   6 +
>  6 files changed, 578 insertions(+)

Reviewed-by: Simon Glass <sjg@chromium.org>

nits below

>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 66783d636e3d..6d2b87720565 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -939,6 +939,13 @@ F: include/bootstd.h
>  F:     net/eth_bootdevice.c
>  F:     test/boot/
>
> +BOOTMETH_ANDROID
> +M:     Mattijs Korpershoek <mkorpershoek@baylibre.com>
> +S:     Maintained
> +T:     git https://source.denx.de/u-boot/custodians/u-boot-dfu.git
> +F:     boot/bootmeth_android.c
> +F:     boot/bootmeth_android.h
> +
>  BTRFS
>  M:     Marek Behún <kabel@kernel.org>
>  R:     Qu Wenruo <wqu@suse.com>
> diff --git a/boot/Kconfig b/boot/Kconfig
> index 6f3096c15a6f..5fa6f3b8315d 100644
> --- a/boot/Kconfig
> +++ b/boot/Kconfig
> @@ -494,6 +494,20 @@ config BOOTMETH_GLOBAL
>           EFI bootmgr, since they take full control over which bootdevs are
>           selected to boot.
>
> +config BOOTMETH_ANDROID
> +       bool "Bootdev support for Android"
> +       depends on X86 || ARM || SANDBOX
> +       select ANDROID_AB
> +       select ANDROID_BOOT_IMAGE
> +       select CMD_BCB
> +       select PARTITION_TYPE_GUID
> +       select PARTITION_UUIDS
> +       help
> +         Enables support for booting Android using bootdevs. Android requires

using standard boot (or using bootstd).

> +         multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
> +
> +         Note that only MMC bootdevs are supported at present.

Why is that limitation present? Can you please mention what is needed
to remove it?

> +
>  config BOOTMETH_CROS
>         bool "Bootdev support for Chromium OS"
>         depends on X86 || ARM || SANDBOX
> diff --git a/boot/Makefile b/boot/Makefile
> index 84ccfeaecec4..75d1cd46fabf 100644
> --- a/boot/Makefile
> +++ b/boot/Makefile
> @@ -66,3 +66,5 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_REQUEST) += vbe_request.o
>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o
>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o
>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o
> +
> +obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_ANDROID) += bootmeth_android.o
> diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c
> new file mode 100644
> index 000000000000..26d548d2fd6e
> --- /dev/null
> +++ b/boot/bootmeth_android.c
> @@ -0,0 +1,522 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Bootmethod for Android

This is my fault, but I think we should settle on Bootmeth throughout.

> + *
> + * Copyright (C) 2024 BayLibre, SAS
> + * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
> + */
> +#define LOG_CATEGORY UCLASS_BOOTSTD
> +
> +#include <android_ab.h>
> +#include <android_image.h>
> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
> +#include <avb_verify.h>

Can you include that header always?

> +#endif
> +#include <bcb.h>
> +#include <blk.h>
> +#include <bootflow.h>
> +#include <bootm.h>
> +#include <bootmeth.h>
> +#include <dm.h>
> +#include <image.h>
> +#include <malloc.h>
> +#include <mapmem.h>
> +#include <part.h>
> +#include "bootmeth_android.h"
> +
> +#define BCB_FIELD_COMMAND_SZ 32
> +#define BCB_PART_NAME "misc"
> +#define BOOT_PART_NAME "boot"
> +#define VENDOR_BOOT_PART_NAME "vendor_boot"
> +
> +/**
> + * struct android_priv - Private data
> + *
> + * This is read from the disk and recorded for use when the full Android
> + * kernel must be loaded and booted

please add member comments as I don't know what these fields are

> + */
> +struct android_priv {
> +       int boot_mode;
> +       char slot[2];
> +       u32 header_version;
> +};
> +
> +static int android_check(struct udevice *dev, struct bootflow_iter *iter)
> +{
> +       /* This only works on mmc devices */
> +       if (bootflow_iter_check_mmc(iter))
> +               return log_msg_ret("mmc", -ENOTSUPP);
> +
> +       /* This only works on whole devices, as multiple
> +        * partitions are needed to boot Android
> +        */
> +       if (iter->part != 0)
> +               return log_msg_ret("mmc part", -ENOTSUPP);
> +
> +       return 0;
> +}
> +
> +static int scan_boot_part(struct udevice *blk, struct android_priv *priv)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(blk);
> +       struct disk_partition partition;
> +       char partname[PART_NAME_LEN];
> +       ulong num_blks, bufsz;
> +       char *buf;
> +       int ret;
> +
> +       sprintf(partname, BOOT_PART_NAME "_%s", priv->slot);
> +       ret = part_get_info_by_name(desc, partname, &partition);
> +       if (ret < 0)
> +               return log_msg_ret("part info", ret);
> +
> +       num_blks = DIV_ROUND_UP(sizeof(struct andr_boot_img_hdr_v0), desc->blksz);
> +       bufsz = num_blks * desc->blksz;
> +       buf = malloc(bufsz);
> +       if (!buf)
> +               return log_msg_ret("buf", -ENOMEM);
> +
> +       ret = blk_read(blk, partition.start, num_blks, buf);
> +       if (ret != num_blks) {
> +               free(buf);
> +               return log_msg_ret("part read", -EIO);
> +       }
> +
> +       if (!is_android_boot_image_header(buf)) {
> +               free(buf);
> +               return log_msg_ret("header", -ENOENT);
> +       }
> +
> +       priv->header_version = android_image_get_version(buf);
> +
> +       return 0;
> +}
> +
> +static int scan_vendor_boot_part(struct udevice *blk, const char slot[2])
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(blk);
> +       struct disk_partition partition;
> +       char partname[PART_NAME_LEN];
> +       ulong num_blks, bufsz;
> +       char *buf;
> +       int ret;
> +
> +       sprintf(partname, VENDOR_BOOT_PART_NAME "_%s", slot);
> +       ret = part_get_info_by_name(desc, partname, &partition);
> +       if (ret < 0)
> +               return log_msg_ret("part info", ret);
> +
> +       num_blks = DIV_ROUND_UP(sizeof(struct andr_vnd_boot_img_hdr), desc->blksz);
> +       bufsz = num_blks * desc->blksz;
> +       buf = malloc(bufsz);
> +       if (!buf)
> +               return log_msg_ret("buf", -ENOMEM);
> +
> +       ret = blk_read(blk, partition.start, num_blks, buf);
> +       if (ret != num_blks) {
> +               free(buf);
> +               return log_msg_ret("part read", -EIO);
> +       }
> +
> +       if (!is_android_vendor_boot_image_header(buf)) {
> +               free(buf);
> +               return log_msg_ret("header", -ENOENT);
> +       }
> +
> +       return 0;
> +}
> +
> +static int android_read_slot_from_bcb(struct bootflow *bflow, bool decrement)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
> +       struct android_priv *priv = bflow->bootmeth_priv;
> +       struct disk_partition misc;
> +       char slot_suffix[3];
> +       int ret;
> +
> +       ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
> +       if (ret < 0)
> +               return log_msg_ret("part", ret);
> +
> +       ret = ab_select_slot(desc, &misc, decrement);
> +       if (ret < 0)
> +               return log_msg_ret("slot", ret);
> +
> +       priv->slot[0] = BOOT_SLOT_NAME(ret);
> +       priv->slot[1] = '\0';
> +
> +       sprintf(slot_suffix, "_%s", priv->slot);
> +       ret = bootflow_cmdline_set_arg(bflow, "androidboot.slot_suffix",
> +                                      slot_suffix, false);
> +       if (ret < 0)
> +               return log_msg_ret("slot", ret);

perhaps "cmdl" ?

> +
> +       return 0;
> +}
> +
> +static int configure_serialno(struct bootflow *bflow)
> +{
> +       char *serialno = env_get("serial#");
> +
> +       if (!serialno)
> +               return log_msg_ret("serial", -ENOENT);
> +
> +       return bootflow_cmdline_set_arg(bflow, "androidboot.serialno", serialno, false);
> +}
> +
> +static int android_read_bootflow(struct udevice *dev, struct bootflow *bflow)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
> +       struct disk_partition misc;
> +       struct android_priv *priv;
> +       char command[BCB_FIELD_COMMAND_SZ];
> +       int ret;
> +
> +       bflow->state = BOOTFLOWST_MEDIA;
> +
> +       /* bcb_find_partition_and_load() will print errors to stdout

I believe this first line should just be /*

> +        * if BCB_PART_NAME is not found. To avoid that, check if the
> +        * partition exists first.
> +        */
> +       ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
> +       if (ret < 0)
> +               return log_msg_ret("part", ret);
> +
> +       ret = bcb_find_partition_and_load("mmc", desc->devnum, BCB_PART_NAME);
> +       if (ret < 0)
> +               return log_msg_ret("bcb load", ret);
> +
> +       ret = bcb_get(BCB_FIELD_COMMAND, command, sizeof(command));
> +       if (ret < 0)
> +               return log_msg_ret("bcb read", ret);
> +
> +       priv = malloc(sizeof(struct android_priv));
> +       if (!priv)
> +               return log_msg_ret("buf", -ENOMEM);
> +
> +       bflow->bootmeth_priv = priv;

ideally this would happen at the end of the function

> +       if (!strcmp("bootonce-bootloader", command)) {
> +               priv->boot_mode = ANDROID_BOOT_MODE_BOOTLOADER;
> +               bflow->os_name = strdup("Android (bootloader)");
> +       } else if (!strcmp("boot-fastboot", command)) {
> +               priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
> +               bflow->os_name = strdup("Android (fastbootd)");
> +       } else if (!strcmp("boot-recovery", command)) {
> +               priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
> +               bflow->os_name = strdup("Android (recovery)");
> +       } else {
> +               priv->boot_mode = ANDROID_BOOT_MODE_NORMAL;
> +               bflow->os_name = strdup("Android");
> +       }
> +       if (!bflow->os_name)
> +               return log_msg_ret("os", -ENOMEM);
> +
> +       if (priv->boot_mode == ANDROID_BOOT_MODE_BOOTLOADER) {
> +               /* Clear BCB */
> +               memset(command, 0, sizeof(command));
> +               ret = bcb_set(BCB_FIELD_COMMAND, command);
> +               if (ret < 0) {
> +                       free(priv);
> +                       return log_msg_ret("bcb set", ret);
> +               }
> +               ret = bcb_store();
> +               if (ret < 0) {
> +                       free(priv);
> +                       return log_msg_ret("bcb store", ret);
> +               }
> +
> +               bflow->state = BOOTFLOWST_READY;
> +               return 0;
> +       }
> +
> +       /* For recovery and normal boot, we need to scan the partitions */
> +       ret = android_read_slot_from_bcb(bflow, false);
> +       if (ret < 0) {
> +               free(priv);
> +               return log_msg_ret("read slot", ret);
> +       }
> +
> +       ret = scan_boot_part(bflow->blk, priv);
> +       if (ret < 0) {
> +               printf("- scan boot failed: err=%d\n", ret);
> +               free(priv);
> +               return log_msg_ret("scan boot", ret);
> +       }
> +
> +       if (priv->header_version != 4) {
> +               printf("- Only boot.img v4 is supported\n");

shouldn't this be log_debug() ?

> +               free(priv);
> +               return log_msg_ret("version", -EINVAL);
> +       }
> +
> +       ret = scan_vendor_boot_part(bflow->blk, priv->slot);
> +       if (ret < 0) {
> +               printf("- scan vendor_boot failed: err=%d\n", ret);
> +               free(priv);
> +               return log_msg_ret("scan vendor_boot", ret);
> +       }
> +
> +       /* Ignoring return code: setting serial number is not mandatory for booting */
> +       configure_serialno(bflow);
> +
> +       if (priv->boot_mode == ANDROID_BOOT_MODE_NORMAL) {
> +               ret = bootflow_cmdline_set_arg(bflow, "androidboot.force_normal_boot", "1", false);

check line length

> +               if (ret < 0) {
> +                       free(priv);
> +                       return log_msg_ret("normal_boot", ret);
> +               }
> +       }
> +
> +       bflow->state = BOOTFLOWST_READY;
> +
> +       return 0;
> +}
> +
> +static int android_read_file(struct udevice *dev, struct bootflow *bflow,
> +                            const char *file_path, ulong addr, ulong *sizep)
> +{
> +       /* Reading individual files is not supported since we only
> +        * operate on whole mmc devices (because we require multiple partitions)
> +        */
> +       return log_msg_ret("Unsupported", -ENOSYS);
> +}
> +
> +static int read_slotted_partition(struct blk_desc *desc, const char *const name,
> +                                 const char slot[2], ulong addr)

What is a slotted partition? This function could use a comment

> +{
> +       struct disk_partition partition;
> +       char partname[PART_NAME_LEN];
> +       int ret;
> +       u32 n;
> +
> +       /* Ensure name fits in partname it should be: <name>_<slot>\0 */
> +       if (strlen(name) > (PART_NAME_LEN - 2 - 1))
> +               return log_msg_ret("name too long", -EINVAL);
> +
> +       sprintf(partname, "%s_%s", name, slot);
> +       ret = part_get_info_by_name(desc, partname, &partition);
> +       if (ret < 0)
> +               return log_msg_ret("part", ret);
> +
> +       n = blk_dread(desc, partition.start, partition.size, map_sysmem(addr, 0));
> +       if (n < partition.size)
> +               return log_msg_ret("part read", -EIO);
> +
> +       return 0;
> +}
> +
> +#if CONFIG_IS_ENABLED(AVB_VERIFY)

Can you use if() instead, and either rename the functions below or add
this if() to each function?

> +static int avb_append_commandline_arg(struct bootflow *bflow, char *arg)
> +{
> +       char *key = strsep(&arg, "=");
> +       char *value = arg;
> +       int ret;
> +
> +       ret = bootflow_cmdline_set_arg(bflow, key, value, false);
> +       if (ret < 0)
> +               return log_msg_ret("avb cmdline", ret);
> +
> +       return 0;
> +}
> +
> +static int avb_append_commandline(struct bootflow *bflow, char *cmdline)
> +{
> +       char *arg = strsep(&cmdline, " ");
> +       int ret;
> +
> +       while (arg) {
> +               ret = avb_append_commandline_arg(bflow, arg);
> +               if (ret < 0)
> +                       return ret;
> +
> +               arg = strsep(&cmdline, " ");
> +       }
> +
> +       return 0;
> +}
> +
> +static int run_avb_verification(struct bootflow *bflow)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
> +       struct android_priv *priv = bflow->bootmeth_priv;
> +       const char * const requested_partitions[] = {"boot", "vendor_boot"};
> +       struct AvbOps *avb_ops;
> +       AvbSlotVerifyResult result;
> +       AvbSlotVerifyData *out_data;
> +       enum avb_boot_state boot_state;
> +       char *extra_args;
> +       char slot_suffix[3];
> +       bool unlocked = false;
> +       int ret;
> +
> +       avb_ops = avb_ops_alloc(desc->devnum);
> +       if (!avb_ops)
> +               return log_msg_ret("avb ops", -ENOMEM);
> +
> +       sprintf(slot_suffix, "_%s", priv->slot);
> +
> +       ret = avb_ops->read_is_device_unlocked(avb_ops, &unlocked);
> +       if (ret != AVB_IO_RESULT_OK)
> +               return log_msg_ret("avb lock", -EIO);
> +
> +       result = avb_slot_verify(avb_ops,
> +                                requested_partitions,
> +                                slot_suffix,
> +                                unlocked,
> +                                AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
> +                                &out_data);
> +
> +       if (result != AVB_SLOT_VERIFY_RESULT_OK) {
> +               printf("Verification failed, reason: %s\n",
> +                      str_avb_slot_error(result));
> +               return log_msg_ret("avb verify", -EIO);
> +       }
> +
> +       if (unlocked)
> +               boot_state = AVB_ORANGE;
> +       else
> +               boot_state = AVB_GREEN;
> +
> +       extra_args = avb_set_state(avb_ops, boot_state);
> +       if (extra_args) {
> +               ret = avb_append_commandline_arg(bflow, extra_args);

This function will write to extra_args...is that OK?

> +               if (ret < 0)
> +                       goto free_out_data;
> +       }
> +
> +       ret = avb_append_commandline(bflow, out_data->cmdline);
> +       if (ret < 0)
> +               goto free_out_data;
> +
> +       return 0;
> +
> + free_out_data:
> +       if (out_data)
> +               avb_slot_verify_data_free(out_data);
> +
> +       return log_msg_ret("avb cmdline", ret);
> +}
> +#else
> +static int run_avb_verification(struct bootflow *bflow)
> +{
> +       int ret;
> +
> +       /* When AVB is unsupported, pass ORANGE state  */
> +       ret = bootflow_cmdline_set_arg(bflow,
> +                                      "androidboot.verifiedbootstate",
> +                                      "orange", false);
> +       if (ret < 0)
> +               return log_msg_ret("avb cmdline", ret);
> +
> +       return 0;
> +}
> +#endif /* AVB_VERIFY */
> +
> +static int boot_android_normal(struct bootflow *bflow)
> +{
> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
> +       struct android_priv *priv = bflow->bootmeth_priv;
> +       int ret;
> +

drop blank line

> +       ulong loadaddr = env_get_hex("loadaddr", 0);
> +       ulong vloadaddr = env_get_hex("vendor_boot_comp_addr_r", 0);
> +
> +       ret = run_avb_verification(bflow);
> +       if (ret < 0)
> +               return log_msg_ret("avb", ret);
> +
> +       /* Read slot once more to decrement counter from BCB */
> +       ret = android_read_slot_from_bcb(bflow, true);
> +       if (ret < 0)
> +               return log_msg_ret("read slot", ret);
> +
> +       ret = read_slotted_partition(desc, "boot", priv->slot, loadaddr);
> +       if (ret < 0)
> +               return log_msg_ret("read boot", ret);
> +
> +       ret = read_slotted_partition(desc, "vendor_boot", priv->slot, vloadaddr);
> +       if (ret < 0)
> +               return log_msg_ret("read vendor_boot", ret);
> +
> +       set_abootimg_addr(loadaddr);
> +       set_avendor_bootimg_addr(vloadaddr);
> +
> +       ret = bootm_boot_start(loadaddr, bflow->cmdline);
> +
> +       return log_msg_ret("boot", ret);
> +}
> +
> +static int boot_android_recovery(struct bootflow *bflow)
> +{
> +       int ret;
> +
> +       ret = boot_android_normal(bflow);
> +
> +       return log_msg_ret("boot", ret);
> +}
> +
> +static int boot_android_bootloader(struct bootflow *bflow)
> +{
> +       int ret;
> +
> +       ret = run_command("fastboot usb 0", 0);
> +       do_reset(NULL, 0, 0, NULL);
> +
> +       return log_msg_ret("boot", ret);
> +}
> +
> +static int android_boot(struct udevice *dev, struct bootflow *bflow)
> +{
> +       struct android_priv *priv = bflow->bootmeth_priv;
> +       int ret;
> +
> +       switch (priv->boot_mode) {
> +       case ANDROID_BOOT_MODE_NORMAL:
> +               ret = boot_android_normal(bflow);
> +               break;
> +       case ANDROID_BOOT_MODE_RECOVERY:
> +               ret = boot_android_recovery(bflow);
> +               break;
> +       case ANDROID_BOOT_MODE_BOOTLOADER:
> +               ret = boot_android_bootloader(bflow);
> +               break;
> +       default:
> +               printf("ANDROID: Unknown boot mode %d. Running fastboot...\n",
> +                      priv->boot_mode);
> +               boot_android_bootloader(bflow);
> +               /* Tell we failed to boot since boot mode is unknown */
> +               ret = -EFAULT;
> +       }
> +
> +       return ret;
> +}
> +
> +static int android_bootmeth_bind(struct udevice *dev)
> +{
> +       struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
> +
> +       plat->desc = "Android boot";
> +       plat->flags = BOOTMETHF_ANY_PART;
> +
> +       return 0;
> +}
> +
> +static struct bootmeth_ops android_bootmeth_ops = {
> +       .check          = android_check,
> +       .read_bootflow  = android_read_bootflow,
> +       .read_file      = android_read_file,
> +       .boot           = android_boot,
> +};
> +
> +static const struct udevice_id android_bootmeth_ids[] = {
> +       { .compatible = "u-boot,android" },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(bootmeth_android) = {
> +       .name           = "bootmeth_android",
> +       .id             = UCLASS_BOOTMETH,
> +       .of_match       = android_bootmeth_ids,
> +       .ops            = &android_bootmeth_ops,
> +       .bind           = android_bootmeth_bind,
> +};
> diff --git a/boot/bootmeth_android.h b/boot/bootmeth_android.h
> new file mode 100644
> index 000000000000..411c2f2d15e7
> --- /dev/null
> +++ b/boot/bootmeth_android.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Bootmethod for Android
> + *
> + * Copyright (C) 2024 BayLibre, SAS
> + * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
> + */
> +
> +enum android_boot_mode {
> +       ANDROID_BOOT_MODE_NORMAL = 0,
> +
> +       /* Android "recovery" is a special boot mode that uses another ramdisk.
> +        * It can be used to "factory reset" a board or to flash logical partitions
> +        * It operates in 2 modes: adb or fastbootd
> +        * To enter recovery from Android, we can do:
> +        * $ adb reboot recovery
> +        * $ adb reboot fastboot
> +        */
> +       ANDROID_BOOT_MODE_RECOVERY,
> +
> +       /* Android "bootloader" is for accessing/reflashing physical partitions
> +        * Typically, this will launch a fastboot process in U-Boot.
> +        * To enter "bootloader" from Android, we can do:
> +        * $ adb reboot bootloader
> +        */
> +       ANDROID_BOOT_MODE_BOOTLOADER,
> +};
> diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst
> index a07a72581e7a..709fa9e64ff3 100644
> --- a/doc/develop/bootstd.rst
> +++ b/doc/develop/bootstd.rst
> @@ -95,6 +95,7 @@ bootflows.
>
>  Note: it is possible to have a bootmeth that uses a partition or a whole device
>  directly, but it is more common to use a filesystem.
> +For example, the Android bootmeth uses a whole device.
>
>  Note that some bootmeths are 'global', meaning that they select the bootdev
>  themselves. Examples include VBE and EFI boot manager. In this case, they
> @@ -277,6 +278,9 @@ script_offset_f
>  script_size_f
>      Size of the script to load, e.g. 0x2000
>
> +vendor_boot_comp_addr_r
> +    Address to which to load the vendor_boot Android image, e.g. 0xe0000000
> +
>  Some variables are set by script bootmeth:
>
>  devtype
> @@ -418,6 +422,7 @@ Bootmeth drivers are provided for:
>     - EFI boot using bootefi from disk
>     - VBE
>     - EFI boot using boot manager
> +   - Android bootflow (boot image v4)
>
>
>  Command interface
> @@ -786,6 +791,7 @@ To do
>  Some things that need to be done to completely replace the distro-boot scripts:
>
>  - implement extensions (devicetree overlays with add-on boards)
> +- implement legacy (boot image v2) android boot flow

Nice!

>
>  Other ideas:
>
>
> --
> 2.45.0
>

Regards,
Simon

Re: [PATCH 6/6] bootstd: Add test for bootmeth_android

[Simon Glass]

On Thu, 6 Jun 2024 at 06:24, Mattijs Korpershoek
<mkorpershoek@baylibre.com> wrote:
>
> Add a unit test for testing the Android bootmethod.
>
> This requires another mmc image (mmc7) to contain the following partitions:
> - misc: contains the Bootloader Control Block (BCB)
> - boot_a: contains a fake generic kernel image
> - vendor_boot_a: contains a fake vendor_boot image
>
> Also add BOOTMETH_ANDROID as a dependency on sandbox so that we can test
> this with:
>
> $ ./test/py/test.py --bd sandbox --build -k test_ut # to build the mmc7.img
> $ ./test/py/test.py --bd sandbox --build -k bootflow_android
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> ---
>  arch/sandbox/dts/test.dts |  8 +++++
>  configs/sandbox_defconfig |  2 +-
>  test/boot/bootflow.c      | 65 ++++++++++++++++++++++++++++++++++++++--
>  test/py/tests/test_ut.py  | 76 +++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 147 insertions(+), 4 deletions(-)
>

Reviewed-by: Simon Glass <sjg@chromium.org>

Re: [PATCH 5/6] bootstd: Add a bootmeth for Android

[Mattijs Korpershoek]

Hi Simon,

Thank you for your review.

On mar., juin 11, 2024 at 12:52, Simon Glass <sjg@chromium.org> wrote:

> Hi Mattijs,
>
> On Thu, 6 Jun 2024 at 06:24, Mattijs Korpershoek
> <mkorpershoek@baylibre.com> wrote:
>>
>> Android boot flow is a bit different than a regular Linux distro.
>> Android relies on multiple partitions in order to boot.
>>
>> A typical boot flow would be:
>> 1. Parse the Bootloader Control Block (BCB, misc partition)
>> 2. If BCB requested bootonce-bootloader, start fastboot and wait.
>> 3. If BCB requested recovery or normal android, run the following:
>> 3.a. Get slot (A/B) from BCB
>> 3.b. Run AVB (Android Verified Boot) on boot partitions
>> 3.c. Load boot and vendor_boot partitions
>> 3.d. Load device-tree, ramdisk and boot
>>
>> The AOSP documentation has more details at [1], [2], [3]
>>
>> This has been implemented via complex boot scripts such as [4].
>> However, these boot script are neither very maintainable nor generic.
>> Moreover, DISTRO_DEFAULTS is being deprecated [5].
>>
>> Add a generic Android bootflow implementation for bootstd.
>> For this initial version, only boot image v4 is supported.
>>
>> [1] https://source.android.com/docs/core/architecture/bootloader
>> [2] https://source.android.com/docs/core/architecture/partitions
>> [3] https://source.android.com/docs/core/architecture/partitions/generic-boot
>> [4] https://source.denx.de/u-boot/u-boot/-/blob/master/include/configs/meson64_android.h
>> [5] https://lore.kernel.org/r/all/20230914165615.1058529-17-sjg@chromium.org/
>>
>> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> ---
>>  MAINTAINERS             |   7 +
>>  boot/Kconfig            |  14 ++
>>  boot/Makefile           |   2 +
>>  boot/bootmeth_android.c | 522 ++++++++++++++++++++++++++++++++++++++++++++++++
>>  boot/bootmeth_android.h |  27 +++
>>  doc/develop/bootstd.rst |   6 +
>>  6 files changed, 578 insertions(+)
>
> Reviewed-by: Simon Glass <sjg@chromium.org>
>
> nits below
>
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 66783d636e3d..6d2b87720565 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -939,6 +939,13 @@ F: include/bootstd.h
>>  F:     net/eth_bootdevice.c
>>  F:     test/boot/
>>
>> +BOOTMETH_ANDROID
>> +M:     Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> +S:     Maintained
>> +T:     git https://source.denx.de/u-boot/custodians/u-boot-dfu.git
>> +F:     boot/bootmeth_android.c
>> +F:     boot/bootmeth_android.h
>> +
>>  BTRFS
>>  M:     Marek Behún <kabel@kernel.org>
>>  R:     Qu Wenruo <wqu@suse.com>
>> diff --git a/boot/Kconfig b/boot/Kconfig
>> index 6f3096c15a6f..5fa6f3b8315d 100644
>> --- a/boot/Kconfig
>> +++ b/boot/Kconfig
>> @@ -494,6 +494,20 @@ config BOOTMETH_GLOBAL
>>           EFI bootmgr, since they take full control over which bootdevs are
>>           selected to boot.
>>
>> +config BOOTMETH_ANDROID
>> +       bool "Bootdev support for Android"
>> +       depends on X86 || ARM || SANDBOX
>> +       select ANDROID_AB
>> +       select ANDROID_BOOT_IMAGE
>> +       select CMD_BCB
>> +       select PARTITION_TYPE_GUID
>> +       select PARTITION_UUIDS
>> +       help
>> +         Enables support for booting Android using bootdevs. Android requires
>
> using standard boot (or using bootstd).

Will do for v2.

>
>> +         multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
>> +
>> +         Note that only MMC bootdevs are supported at present.
>
> Why is that limitation present? Can you please mention what is needed
> to remove it?

Mainly because we use AVB and AVB is hard-coded for MMC. Alistair
submitted changes to convert to generic block devices here:

https://lore.kernel.org/all/20220926220211.868968-1-adelva@google.com/

There were some review comments but I did not see any v2 on the list.

I will add a comment in the KConfig description.

>
>> +
>>  config BOOTMETH_CROS
>>         bool "Bootdev support for Chromium OS"
>>         depends on X86 || ARM || SANDBOX
>> diff --git a/boot/Makefile b/boot/Makefile
>> index 84ccfeaecec4..75d1cd46fabf 100644
>> --- a/boot/Makefile
>> +++ b/boot/Makefile
>> @@ -66,3 +66,5 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_REQUEST) += vbe_request.o
>>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o
>>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o
>>  obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o
>> +
>> +obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_ANDROID) += bootmeth_android.o
>> diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c
>> new file mode 100644
>> index 000000000000..26d548d2fd6e
>> --- /dev/null
>> +++ b/boot/bootmeth_android.c
>> @@ -0,0 +1,522 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Bootmethod for Android
>
> This is my fault, but I think we should settle on Bootmeth throughout.

Yes, thank you for noticing. Will do for v2.

>
>> + *
>> + * Copyright (C) 2024 BayLibre, SAS
>> + * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> + */
>> +#define LOG_CATEGORY UCLASS_BOOTSTD
>> +
>> +#include <android_ab.h>
>> +#include <android_image.h>
>> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
>> +#include <avb_verify.h>
>
> Can you include that header always?

I can't, it does not link if I do.

It would be possible if we implemented stub functions but that's not the
case today.

Since this is a nitpick, I will consider this for a future improvement.

>
>> +#endif
>> +#include <bcb.h>
>> +#include <blk.h>
>> +#include <bootflow.h>
>> +#include <bootm.h>
>> +#include <bootmeth.h>
>> +#include <dm.h>
>> +#include <image.h>
>> +#include <malloc.h>
>> +#include <mapmem.h>
>> +#include <part.h>
>> +#include "bootmeth_android.h"
>> +
>> +#define BCB_FIELD_COMMAND_SZ 32
>> +#define BCB_PART_NAME "misc"
>> +#define BOOT_PART_NAME "boot"
>> +#define VENDOR_BOOT_PART_NAME "vendor_boot"
>> +
>> +/**
>> + * struct android_priv - Private data
>> + *
>> + * This is read from the disk and recorded for use when the full Android
>> + * kernel must be loaded and booted
>
> please add member comments as I don't know what these fields are

Will do for v2.

>
>> + */
>> +struct android_priv {
>> +       int boot_mode;
>> +       char slot[2];
>> +       u32 header_version;
>> +};
>> +
>> +static int android_check(struct udevice *dev, struct bootflow_iter *iter)
>> +{
>> +       /* This only works on mmc devices */
>> +       if (bootflow_iter_check_mmc(iter))
>> +               return log_msg_ret("mmc", -ENOTSUPP);
>> +
>> +       /* This only works on whole devices, as multiple
>> +        * partitions are needed to boot Android
>> +        */
>> +       if (iter->part != 0)
>> +               return log_msg_ret("mmc part", -ENOTSUPP);
>> +
>> +       return 0;
>> +}
>> +
>> +static int scan_boot_part(struct udevice *blk, struct android_priv *priv)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(blk);
>> +       struct disk_partition partition;
>> +       char partname[PART_NAME_LEN];
>> +       ulong num_blks, bufsz;
>> +       char *buf;
>> +       int ret;
>> +
>> +       sprintf(partname, BOOT_PART_NAME "_%s", priv->slot);
>> +       ret = part_get_info_by_name(desc, partname, &partition);
>> +       if (ret < 0)
>> +               return log_msg_ret("part info", ret);
>> +
>> +       num_blks = DIV_ROUND_UP(sizeof(struct andr_boot_img_hdr_v0), desc->blksz);
>> +       bufsz = num_blks * desc->blksz;
>> +       buf = malloc(bufsz);
>> +       if (!buf)
>> +               return log_msg_ret("buf", -ENOMEM);
>> +
>> +       ret = blk_read(blk, partition.start, num_blks, buf);
>> +       if (ret != num_blks) {
>> +               free(buf);
>> +               return log_msg_ret("part read", -EIO);
>> +       }
>> +
>> +       if (!is_android_boot_image_header(buf)) {
>> +               free(buf);
>> +               return log_msg_ret("header", -ENOENT);
>> +       }
>> +
>> +       priv->header_version = android_image_get_version(buf);
>> +
>> +       return 0;
>> +}
>> +
>> +static int scan_vendor_boot_part(struct udevice *blk, const char slot[2])
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(blk);
>> +       struct disk_partition partition;
>> +       char partname[PART_NAME_LEN];
>> +       ulong num_blks, bufsz;
>> +       char *buf;
>> +       int ret;
>> +
>> +       sprintf(partname, VENDOR_BOOT_PART_NAME "_%s", slot);
>> +       ret = part_get_info_by_name(desc, partname, &partition);
>> +       if (ret < 0)
>> +               return log_msg_ret("part info", ret);
>> +
>> +       num_blks = DIV_ROUND_UP(sizeof(struct andr_vnd_boot_img_hdr), desc->blksz);
>> +       bufsz = num_blks * desc->blksz;
>> +       buf = malloc(bufsz);
>> +       if (!buf)
>> +               return log_msg_ret("buf", -ENOMEM);
>> +
>> +       ret = blk_read(blk, partition.start, num_blks, buf);
>> +       if (ret != num_blks) {
>> +               free(buf);
>> +               return log_msg_ret("part read", -EIO);
>> +       }
>> +
>> +       if (!is_android_vendor_boot_image_header(buf)) {
>> +               free(buf);
>> +               return log_msg_ret("header", -ENOENT);
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int android_read_slot_from_bcb(struct bootflow *bflow, bool decrement)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> +       struct android_priv *priv = bflow->bootmeth_priv;
>> +       struct disk_partition misc;
>> +       char slot_suffix[3];
>> +       int ret;
>> +
>> +       ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
>> +       if (ret < 0)
>> +               return log_msg_ret("part", ret);
>> +
>> +       ret = ab_select_slot(desc, &misc, decrement);
>> +       if (ret < 0)
>> +               return log_msg_ret("slot", ret);
>> +
>> +       priv->slot[0] = BOOT_SLOT_NAME(ret);
>> +       priv->slot[1] = '\0';
>> +
>> +       sprintf(slot_suffix, "_%s", priv->slot);
>> +       ret = bootflow_cmdline_set_arg(bflow, "androidboot.slot_suffix",
>> +                                      slot_suffix, false);
>> +       if (ret < 0)
>> +               return log_msg_ret("slot", ret);
>
> perhaps "cmdl" ?

Yes, will do for v2.

>
>> +
>> +       return 0;
>> +}
>> +
>> +static int configure_serialno(struct bootflow *bflow)
>> +{
>> +       char *serialno = env_get("serial#");
>> +
>> +       if (!serialno)
>> +               return log_msg_ret("serial", -ENOENT);
>> +
>> +       return bootflow_cmdline_set_arg(bflow, "androidboot.serialno", serialno, false);
>> +}
>> +
>> +static int android_read_bootflow(struct udevice *dev, struct bootflow *bflow)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> +       struct disk_partition misc;
>> +       struct android_priv *priv;
>> +       char command[BCB_FIELD_COMMAND_SZ];
>> +       int ret;
>> +
>> +       bflow->state = BOOTFLOWST_MEDIA;
>> +
>> +       /* bcb_find_partition_and_load() will print errors to stdout
>
> I believe this first line should just be /*

You are right. I've made this mistake in other parts of the file.
Will fix all occurences for v2.

>
>> +        * if BCB_PART_NAME is not found. To avoid that, check if the
>> +        * partition exists first.
>> +        */
>> +       ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
>> +       if (ret < 0)
>> +               return log_msg_ret("part", ret);
>> +
>> +       ret = bcb_find_partition_and_load("mmc", desc->devnum, BCB_PART_NAME);
>> +       if (ret < 0)
>> +               return log_msg_ret("bcb load", ret);
>> +
>> +       ret = bcb_get(BCB_FIELD_COMMAND, command, sizeof(command));
>> +       if (ret < 0)
>> +               return log_msg_ret("bcb read", ret);
>> +
>> +       priv = malloc(sizeof(struct android_priv));
>> +       if (!priv)
>> +               return log_msg_ret("buf", -ENOMEM);
>> +
>> +       bflow->bootmeth_priv = priv;
>
> ideally this would happen at the end of the function

Yes, Igor pointed out as well. It's dangerous to have a dangling
pointer.
Will do for v2.

>
>> +       if (!strcmp("bootonce-bootloader", command)) {
>> +               priv->boot_mode = ANDROID_BOOT_MODE_BOOTLOADER;
>> +               bflow->os_name = strdup("Android (bootloader)");
>> +       } else if (!strcmp("boot-fastboot", command)) {
>> +               priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
>> +               bflow->os_name = strdup("Android (fastbootd)");
>> +       } else if (!strcmp("boot-recovery", command)) {
>> +               priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
>> +               bflow->os_name = strdup("Android (recovery)");
>> +       } else {
>> +               priv->boot_mode = ANDROID_BOOT_MODE_NORMAL;
>> +               bflow->os_name = strdup("Android");
>> +       }
>> +       if (!bflow->os_name)
>> +               return log_msg_ret("os", -ENOMEM);
>> +
>> +       if (priv->boot_mode == ANDROID_BOOT_MODE_BOOTLOADER) {
>> +               /* Clear BCB */
>> +               memset(command, 0, sizeof(command));
>> +               ret = bcb_set(BCB_FIELD_COMMAND, command);
>> +               if (ret < 0) {
>> +                       free(priv);
>> +                       return log_msg_ret("bcb set", ret);
>> +               }
>> +               ret = bcb_store();
>> +               if (ret < 0) {
>> +                       free(priv);
>> +                       return log_msg_ret("bcb store", ret);
>> +               }
>> +
>> +               bflow->state = BOOTFLOWST_READY;
>> +               return 0;
>> +       }
>> +
>> +       /* For recovery and normal boot, we need to scan the partitions */
>> +       ret = android_read_slot_from_bcb(bflow, false);
>> +       if (ret < 0) {
>> +               free(priv);
>> +               return log_msg_ret("read slot", ret);
>> +       }
>> +
>> +       ret = scan_boot_part(bflow->blk, priv);
>> +       if (ret < 0) {
>> +               printf("- scan boot failed: err=%d\n", ret);
>> +               free(priv);
>> +               return log_msg_ret("scan boot", ret);
>> +       }
>> +
>> +       if (priv->header_version != 4) {
>> +               printf("- Only boot.img v4 is supported\n");
>
> shouldn't this be log_debug() ?

Hmm, I've modeled this to be similar to bootmeth_cros, but I can convert
to log_debug(). I don't have a strong opinion on this.

>
>> +               free(priv);
>> +               return log_msg_ret("version", -EINVAL);
>> +       }
>> +
>> +       ret = scan_vendor_boot_part(bflow->blk, priv->slot);
>> +       if (ret < 0) {
>> +               printf("- scan vendor_boot failed: err=%d\n", ret);
>> +               free(priv);
>> +               return log_msg_ret("scan vendor_boot", ret);
>> +       }
>> +
>> +       /* Ignoring return code: setting serial number is not mandatory for booting */
>> +       configure_serialno(bflow);
>> +
>> +       if (priv->boot_mode == ANDROID_BOOT_MODE_NORMAL) {
>> +               ret = bootflow_cmdline_set_arg(bflow, "androidboot.force_normal_boot", "1", false);
>
> check line length

Yes, somehow I missed this with checkpatch.
Will fix for v2.

>
>> +               if (ret < 0) {
>> +                       free(priv);
>> +                       return log_msg_ret("normal_boot", ret);
>> +               }
>> +       }
>> +
>> +       bflow->state = BOOTFLOWST_READY;
>> +
>> +       return 0;
>> +}
>> +
>> +static int android_read_file(struct udevice *dev, struct bootflow *bflow,
>> +                            const char *file_path, ulong addr, ulong *sizep)
>> +{
>> +       /* Reading individual files is not supported since we only
>> +        * operate on whole mmc devices (because we require multiple partitions)
>> +        */
>> +       return log_msg_ret("Unsupported", -ENOSYS);
>> +}
>> +
>> +static int read_slotted_partition(struct blk_desc *desc, const char *const name,
>> +                                 const char slot[2], ulong addr)
>
> What is a slotted partition? This function could use a comment

Most modern Android devices use "Seamless updates", where each partition
is duplicated. For example, the boot partition has boot_a and boot_b.
This is what I called "slotted partition".

See:
https://source.android.com/docs/core/ota/ab
https://source.android.com/docs/core/ota/ab/ab_implement

I will add a comment pointing to the above documentation and some
additional explanation in v2.

>
>> +{
>> +       struct disk_partition partition;
>> +       char partname[PART_NAME_LEN];
>> +       int ret;
>> +       u32 n;
>> +
>> +       /* Ensure name fits in partname it should be: <name>_<slot>\0 */
>> +       if (strlen(name) > (PART_NAME_LEN - 2 - 1))
>> +               return log_msg_ret("name too long", -EINVAL);
>> +
>> +       sprintf(partname, "%s_%s", name, slot);
>> +       ret = part_get_info_by_name(desc, partname, &partition);
>> +       if (ret < 0)
>> +               return log_msg_ret("part", ret);
>> +
>> +       n = blk_dread(desc, partition.start, partition.size, map_sysmem(addr, 0));
>> +       if (n < partition.size)
>> +               return log_msg_ret("part read", -EIO);
>> +
>> +       return 0;
>> +}
>> +
>> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
>
> Can you use if() instead, and either rename the functions below or add
> this if() to each function?

I will try, but most avb_ops related functions are not stubbed so I'm
not sure we can do this easily.

Since this is a nitpick, I might consider this a future improvement (If
stubs are needed, for example).

>
>> +static int avb_append_commandline_arg(struct bootflow *bflow, char *arg)
>> +{
>> +       char *key = strsep(&arg, "=");
>> +       char *value = arg;
>> +       int ret;
>> +
>> +       ret = bootflow_cmdline_set_arg(bflow, key, value, false);
>> +       if (ret < 0)
>> +               return log_msg_ret("avb cmdline", ret);
>> +
>> +       return 0;
>> +}
>> +
>> +static int avb_append_commandline(struct bootflow *bflow, char *cmdline)
>> +{
>> +       char *arg = strsep(&cmdline, " ");
>> +       int ret;
>> +
>> +       while (arg) {
>> +               ret = avb_append_commandline_arg(bflow, arg);
>> +               if (ret < 0)
>> +                       return ret;
>> +
>> +               arg = strsep(&cmdline, " ");
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int run_avb_verification(struct bootflow *bflow)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> +       struct android_priv *priv = bflow->bootmeth_priv;
>> +       const char * const requested_partitions[] = {"boot", "vendor_boot"};
>> +       struct AvbOps *avb_ops;
>> +       AvbSlotVerifyResult result;
>> +       AvbSlotVerifyData *out_data;
>> +       enum avb_boot_state boot_state;
>> +       char *extra_args;
>> +       char slot_suffix[3];
>> +       bool unlocked = false;
>> +       int ret;
>> +
>> +       avb_ops = avb_ops_alloc(desc->devnum);
>> +       if (!avb_ops)
>> +               return log_msg_ret("avb ops", -ENOMEM);
>> +
>> +       sprintf(slot_suffix, "_%s", priv->slot);
>> +
>> +       ret = avb_ops->read_is_device_unlocked(avb_ops, &unlocked);
>> +       if (ret != AVB_IO_RESULT_OK)
>> +               return log_msg_ret("avb lock", -EIO);
>> +
>> +       result = avb_slot_verify(avb_ops,
>> +                                requested_partitions,
>> +                                slot_suffix,
>> +                                unlocked,
>> +                                AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
>> +                                &out_data);
>> +
>> +       if (result != AVB_SLOT_VERIFY_RESULT_OK) {
>> +               printf("Verification failed, reason: %s\n",
>> +                      str_avb_slot_error(result));
>> +               return log_msg_ret("avb verify", -EIO);
>> +       }
>> +
>> +       if (unlocked)
>> +               boot_state = AVB_ORANGE;
>> +       else
>> +               boot_state = AVB_GREEN;
>> +
>> +       extra_args = avb_set_state(avb_ops, boot_state);
>> +       if (extra_args) {
>> +               ret = avb_append_commandline_arg(bflow, extra_args);
>
> This function will write to extra_args...is that OK?

Yes, extra_args is no longer used after this.
I will add a comment to state that this is safe in v2.

>
>> +               if (ret < 0)
>> +                       goto free_out_data;
>> +       }
>> +
>> +       ret = avb_append_commandline(bflow, out_data->cmdline);
>> +       if (ret < 0)
>> +               goto free_out_data;
>> +
>> +       return 0;
>> +
>> + free_out_data:
>> +       if (out_data)
>> +               avb_slot_verify_data_free(out_data);
>> +
>> +       return log_msg_ret("avb cmdline", ret);
>> +}
>> +#else
>> +static int run_avb_verification(struct bootflow *bflow)
>> +{
>> +       int ret;
>> +
>> +       /* When AVB is unsupported, pass ORANGE state  */
>> +       ret = bootflow_cmdline_set_arg(bflow,
>> +                                      "androidboot.verifiedbootstate",
>> +                                      "orange", false);
>> +       if (ret < 0)
>> +               return log_msg_ret("avb cmdline", ret);
>> +
>> +       return 0;
>> +}
>> +#endif /* AVB_VERIFY */
>> +
>> +static int boot_android_normal(struct bootflow *bflow)
>> +{
>> +       struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> +       struct android_priv *priv = bflow->bootmeth_priv;
>> +       int ret;
>> +
>
> drop blank line

Will do for v2.

>
>> +       ulong loadaddr = env_get_hex("loadaddr", 0);
>> +       ulong vloadaddr = env_get_hex("vendor_boot_comp_addr_r", 0);
>> +
>> +       ret = run_avb_verification(bflow);
>> +       if (ret < 0)
>> +               return log_msg_ret("avb", ret);
>> +
>> +       /* Read slot once more to decrement counter from BCB */
>> +       ret = android_read_slot_from_bcb(bflow, true);
>> +       if (ret < 0)
>> +               return log_msg_ret("read slot", ret);
>> +
>> +       ret = read_slotted_partition(desc, "boot", priv->slot, loadaddr);
>> +       if (ret < 0)
>> +               return log_msg_ret("read boot", ret);
>> +
>> +       ret = read_slotted_partition(desc, "vendor_boot", priv->slot, vloadaddr);
>> +       if (ret < 0)
>> +               return log_msg_ret("read vendor_boot", ret);
>> +
>> +       set_abootimg_addr(loadaddr);
>> +       set_avendor_bootimg_addr(vloadaddr);
>> +
>> +       ret = bootm_boot_start(loadaddr, bflow->cmdline);
>> +
>> +       return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int boot_android_recovery(struct bootflow *bflow)
>> +{
>> +       int ret;
>> +
>> +       ret = boot_android_normal(bflow);
>> +
>> +       return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int boot_android_bootloader(struct bootflow *bflow)
>> +{
>> +       int ret;
>> +
>> +       ret = run_command("fastboot usb 0", 0);
>> +       do_reset(NULL, 0, 0, NULL);
>> +
>> +       return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int android_boot(struct udevice *dev, struct bootflow *bflow)
>> +{
>> +       struct android_priv *priv = bflow->bootmeth_priv;
>> +       int ret;
>> +
>> +       switch (priv->boot_mode) {
>> +       case ANDROID_BOOT_MODE_NORMAL:
>> +               ret = boot_android_normal(bflow);
>> +               break;
>> +       case ANDROID_BOOT_MODE_RECOVERY:
>> +               ret = boot_android_recovery(bflow);
>> +               break;
>> +       case ANDROID_BOOT_MODE_BOOTLOADER:
>> +               ret = boot_android_bootloader(bflow);
>> +               break;
>> +       default:
>> +               printf("ANDROID: Unknown boot mode %d. Running fastboot...\n",
>> +                      priv->boot_mode);
>> +               boot_android_bootloader(bflow);
>> +               /* Tell we failed to boot since boot mode is unknown */
>> +               ret = -EFAULT;
>> +       }
>> +
>> +       return ret;
>> +}
>> +
>> +static int android_bootmeth_bind(struct udevice *dev)
>> +{
>> +       struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
>> +
>> +       plat->desc = "Android boot";
>> +       plat->flags = BOOTMETHF_ANY_PART;
>> +
>> +       return 0;
>> +}
>> +
>> +static struct bootmeth_ops android_bootmeth_ops = {
>> +       .check          = android_check,
>> +       .read_bootflow  = android_read_bootflow,
>> +       .read_file      = android_read_file,
>> +       .boot           = android_boot,
>> +};
>> +
>> +static const struct udevice_id android_bootmeth_ids[] = {
>> +       { .compatible = "u-boot,android" },
>> +       { }
>> +};
>> +
>> +U_BOOT_DRIVER(bootmeth_android) = {
>> +       .name           = "bootmeth_android",
>> +       .id             = UCLASS_BOOTMETH,
>> +       .of_match       = android_bootmeth_ids,
>> +       .ops            = &android_bootmeth_ops,
>> +       .bind           = android_bootmeth_bind,
>> +};
>> diff --git a/boot/bootmeth_android.h b/boot/bootmeth_android.h
>> new file mode 100644
>> index 000000000000..411c2f2d15e7
>> --- /dev/null
>> +++ b/boot/bootmeth_android.h
>> @@ -0,0 +1,27 @@
>> +/* SPDX-License-Identifier: GPL-2.0+ */
>> +/*
>> + * Bootmethod for Android
>> + *
>> + * Copyright (C) 2024 BayLibre, SAS
>> + * Written by Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> + */
>> +
>> +enum android_boot_mode {
>> +       ANDROID_BOOT_MODE_NORMAL = 0,
>> +
>> +       /* Android "recovery" is a special boot mode that uses another ramdisk.
>> +        * It can be used to "factory reset" a board or to flash logical partitions
>> +        * It operates in 2 modes: adb or fastbootd
>> +        * To enter recovery from Android, we can do:
>> +        * $ adb reboot recovery
>> +        * $ adb reboot fastboot
>> +        */
>> +       ANDROID_BOOT_MODE_RECOVERY,
>> +
>> +       /* Android "bootloader" is for accessing/reflashing physical partitions
>> +        * Typically, this will launch a fastboot process in U-Boot.
>> +        * To enter "bootloader" from Android, we can do:
>> +        * $ adb reboot bootloader
>> +        */
>> +       ANDROID_BOOT_MODE_BOOTLOADER,
>> +};
>> diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst
>> index a07a72581e7a..709fa9e64ff3 100644
>> --- a/doc/develop/bootstd.rst
>> +++ b/doc/develop/bootstd.rst
>> @@ -95,6 +95,7 @@ bootflows.
>>
>>  Note: it is possible to have a bootmeth that uses a partition or a whole device
>>  directly, but it is more common to use a filesystem.
>> +For example, the Android bootmeth uses a whole device.
>>
>>  Note that some bootmeths are 'global', meaning that they select the bootdev
>>  themselves. Examples include VBE and EFI boot manager. In this case, they
>> @@ -277,6 +278,9 @@ script_offset_f
>>  script_size_f
>>      Size of the script to load, e.g. 0x2000
>>
>> +vendor_boot_comp_addr_r
>> +    Address to which to load the vendor_boot Android image, e.g. 0xe0000000
>> +
>>  Some variables are set by script bootmeth:
>>
>>  devtype
>> @@ -418,6 +422,7 @@ Bootmeth drivers are provided for:
>>     - EFI boot using bootefi from disk
>>     - VBE
>>     - EFI boot using boot manager
>> +   - Android bootflow (boot image v4)
>>
>>
>>  Command interface
>> @@ -786,6 +791,7 @@ To do
>>  Some things that need to be done to completely replace the distro-boot scripts:
>>
>>  - implement extensions (devicetree overlays with add-on boards)
>> +- implement legacy (boot image v2) android boot flow
>
> Nice!

Thank you! It was easier to implement that I imagined, mainly because
the bootflow framework is well written (imo) and the bootmeth_cros example
was very helpful as well.

>
>>
>>  Other ideas:
>>
>>
>> --
>> 2.45.0
>>
>
> Regards,
> Simon