Re: [PATCH v9 10/15] FWU: Add support for the FWU Multi Bank Update feature

Takahiro Akashi
2022-09-08T02:15:41Z

Hi Sughosh,

On Fri, Aug 26, 2022 at 03:27:11PM +0530, Sughosh Ganu wrote:
> The FWU Multi Bank Update feature supports updation of firmware images
> to one of multiple sets(also called banks) of images. The firmware
> images are clubbed together in banks, with the system booting images
> from the active bank. Information on the images such as which bank
> they belong to is stored as part of the metadata structure, which is
> stored on the same storage media as the firmware images on a dedicated
> partition.
>
> At the time of update, the metadata is read to identify the bank to
> which the images need to be flashed(update bank). On a successful
> update, the metadata is modified to set the updated bank as active
> bank to subsequently boot from.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> ---
> Changes since V8:
> * Add comments for API functions
> * Move addition of the FWU Kconfig symbols and Makefile to this patch
>
> drivers/Kconfig | 2 +
> drivers/Makefile | 1 +
> include/fwu.h | 30 +++++
> lib/Kconfig | 6 +
> lib/Makefile | 1 +
> lib/efi_loader/efi_capsule.c | 213 ++++++++++++++++++++++++++++++++++-
> lib/efi_loader/efi_setup.c | 3 +-
> lib/fwu_updates/Kconfig | 32 ++++++
> lib/fwu_updates/Makefile | 7 ++
> lib/fwu_updates/fwu.c | 23 ++++
> 10 files changed, 312 insertions(+), 6 deletions(-)
> create mode 100644 lib/fwu_updates/Kconfig
> create mode 100644 lib/fwu_updates/Makefile
>
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 8b6fead351..75ac149d31 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -44,6 +44,8 @@ source "drivers/fuzz/Kconfig"
>
> source "drivers/fpga/Kconfig"
>
> +source "drivers/fwu-mdata/Kconfig"
> +
> source "drivers/gpio/Kconfig"
>
> source "drivers/hwspinlock/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index eba9940231..af7ed7bdf3 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -84,6 +84,7 @@ obj-y += cache/
> obj-$(CONFIG_CPU) += cpu/
> obj-y += crypto/
> obj-$(CONFIG_FASTBOOT) += fastboot/
> +obj-$(CONFIG_FWU_MDATA) += fwu-mdata/
> obj-y += misc/
> obj-$(CONFIG_MMC) += mmc/
> obj-$(CONFIG_NVME) += nvme/
> diff --git a/include/fwu.h b/include/fwu.h
> index 31c9923ff5..e05e1d1a00 100644
> --- a/include/fwu.h
> +++ b/include/fwu.h
> @@ -60,6 +60,7 @@ struct fwu_mdata_ops {
> };
>
> #define FWU_MDATA_VERSION 0x1
> +#define FWU_IMAGE_ACCEPTED 0x1
>
> /*
> * GUID value defined in the FWU specification for identification
> @@ -69,6 +70,24 @@ struct fwu_mdata_ops {
> EFI_GUID(0x8a7a84a0, 0x8387, 0x40f6, 0xab, 0x41, \
> 0xa8, 0xb9, 0xa5, 0xa6, 0x0d, 0x23)
>
> +/*
> +* GUID value defined in the Dependable Boot specification for
> +* identification of the revert capsule, used for reverting
> +* any image in the updated bank.
> +*/
> +#define FWU_OS_REQUEST_FW_REVERT_GUID \
> + EFI_GUID(0xacd58b4b, 0xc0e8, 0x475f, 0x99, 0xb5, \
> + 0x6b, 0x3f, 0x7e, 0x07, 0xaa, 0xf0)
> +
> +/*
> +* GUID value defined in the Dependable Boot specification for
> +* identification of the accept capsule, used for accepting
> +* an image in the updated bank.
> +*/
> +#define FWU_OS_REQUEST_FW_ACCEPT_GUID \
> + EFI_GUID(0x0c996046, 0xbcc0, 0x4d04, 0x85, 0xec, \
> + 0xe1, 0xfc, 0xed, 0xf1, 0xc6, 0xf8)
> +
> /**
> * fwu_get_mdata() - Get a FWU metadata copy
> * @dev: FWU metadata device
> @@ -265,4 +284,15 @@ void fwu_plat_get_bootidx(void *boot_idx);
> */
> u8 fwu_update_checks_pass(void);
>
> +/**
> + * fwu_trial_state_ctr_start() - Start the Trial State counter
> + *
> + * Start the counter to identify the platform booting in the
> + * Trial State. The counter is implemented as an EFI variable.
> + *
> + * Return: 0 if OK, -ve on error
> + *
> + */
> +int fwu_trial_state_ctr_start(void);
> +
> #endif /* _FWU_H_ */
> diff --git a/lib/Kconfig b/lib/Kconfig
> index 6121c80dc8..6abe1d0a86 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -978,3 +978,9 @@ config LMB_RESERVED_REGIONS
> memory blocks.
>
> endmenu
> +
> +menu "FWU Multi Bank Updates"
> +
> +source lib/fwu_updates/Kconfig
> +
> +endmenu
> diff --git a/lib/Makefile b/lib/Makefile
> index e3deb15287..f2cfd1e428 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_EFI) += efi/
> obj-$(CONFIG_EFI_LOADER) += efi_driver/
> obj-$(CONFIG_EFI_LOADER) += efi_loader/
> obj-$(CONFIG_CMD_BOOTEFI_SELFTEST) += efi_selftest/
> +obj-$(CONFIG_FWU_MULTI_BANK_UPDATE) += fwu_updates/
> obj-$(CONFIG_LZMA) += lzma/
> obj-$(CONFIG_BZIP2) += bzip2/
> obj-$(CONFIG_FIT) += libfdt/
> diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
> index a6b98f066a..44c56443dc 100644
> --- a/lib/efi_loader/efi_capsule.c
> +++ b/lib/efi_loader/efi_capsule.c
> @@ -14,6 +14,7 @@
> #include <env.h>
> #include <fdtdec.h>
> #include <fs.h>
> +#include <fwu.h>
> #include <hang.h>
> #include <malloc.h>
> #include <mapmem.h>
> @@ -32,6 +33,17 @@ static const efi_guid_t efi_guid_firmware_management_capsule_id =
> EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID;
> const efi_guid_t efi_guid_firmware_management_protocol =
> EFI_FIRMWARE_MANAGEMENT_PROTOCOL_GUID;
> +const efi_guid_t fwu_guid_os_request_fw_revert =
> + FWU_OS_REQUEST_FW_REVERT_GUID;
> +const efi_guid_t fwu_guid_os_request_fw_accept =
> + FWU_OS_REQUEST_FW_ACCEPT_GUID;
> +
> +#define FW_ACCEPT_OS (u32)0x8000
> +
> +__maybe_unused static u32 update_index;
> +__maybe_unused static bool capsule_update;
> +__maybe_unused static bool fw_accept_os;
> +static bool image_index_check = true;
>
> #ifdef CONFIG_EFI_CAPSULE_ON_DISK
> /* for file system access */
> @@ -205,7 +217,8 @@ efi_fmp_find(efi_guid_t *image_type, u8 image_index, u64 instance,
> log_debug("+++ desc[%d] index: %d, name: %ls\n",
> j, desc->image_index, desc->image_id_name);
> if (!guidcmp(&desc->image_type_id, image_type) &&
> - (desc->image_index == image_index) &&
> + (!image_index_check ||
> + desc->image_index == image_index) &&
> (!instance ||
> !desc->hardware_instance ||
> desc->hardware_instance == instance))
> @@ -388,6 +401,83 @@ efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_s
> }
> #endif /* CONFIG_EFI_CAPSULE_AUTHENTICATE */
>
> +static bool fwu_empty_capsule(struct efi_capsule_header *capsule)
> +{
> + return !guidcmp(&capsule->capsule_guid,
> + &fwu_guid_os_request_fw_revert) ||
> + !guidcmp(&capsule->capsule_guid,
> + &fwu_guid_os_request_fw_accept);
> +}
> +
> +static efi_status_t fwu_to_efi_error(int err)
> +{
> + efi_status_t ret;
> +
> + switch(err) {
> + case 0:
> + ret = EFI_SUCCESS;
> + break;
> + case -ENODEV:
> + case -ERANGE:
> + case -EIO:
> + ret = EFI_DEVICE_ERROR;
> + break;
> + case -EINVAL:
> + ret = EFI_INVALID_PARAMETER;
> + break;
> + default:
> + ret = EFI_OUT_OF_RESOURCES;
> + }
> +
> + return ret;
> +}
> +
> +static efi_status_t fwu_empty_capsule_process(
> + struct efi_capsule_header *capsule)
> +{
> + int status;
> + u32 active_idx;
> + efi_status_t ret;
> + efi_guid_t *image_guid;
> +
> + if (!guidcmp(&capsule->capsule_guid,
> + &fwu_guid_os_request_fw_revert)) {
> + /*
> + * One of the previously updated image has
> + * failed the OS acceptance test. OS has
> + * requested to revert back to the earlier
> + * boot index
> + */
> + status = fwu_revert_boot_index();
> + ret = fwu_to_efi_error(status);
> + if (ret == EFI_SUCCESS)
> + log_info("Reverted the FWU active_index. Recommend rebooting the system\n");
> + else
> + log_err("Failed to revert the FWU boot index\n");
> + } else {
> + /*
> + * Image accepted by the OS. Set the acceptance
> + * status for the image.
> + */
> + image_guid = (void *)(char *)capsule +
> + capsule->header_size;
> +
> + status = fwu_get_active_index(&active_idx);
> + ret = fwu_to_efi_error(status);
> + if (ret != EFI_SUCCESS) {
> + log_err("Unable to get the active_index from the FWU metadata\n");
> + return ret;
> + }
> +
> + status = fwu_accept_image(image_guid, active_idx);
> + ret = fwu_to_efi_error(status);
> + if (ret != EFI_SUCCESS)
> + log_err("Unable to set the Accept bit for the image %pUs\n",
> + image_guid);
> + }
> +
> + return ret;
> +}
>
> /**
> * efi_capsule_update_firmware - update firmware from capsule
> @@ -407,10 +497,42 @@ static efi_status_t efi_capsule_update_firmware(
> void *image_binary, *vendor_code;
> efi_handle_t *handles;
> efi_uintn_t no_handles;
> - int item;
> + int item, alt_no;
> struct efi_firmware_management_protocol *fmp;
> u16 *abort_reason;
> + efi_guid_t image_type_id;
> efi_status_t ret = EFI_SUCCESS;
> + int status;
> + u8 image_index;
> +
> + if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> + if (!fwu_empty_capsule(capsule_data) &&
> + !fwu_update_checks_pass()) {
> + log_err("FWU checks failed. Cannot start update\n");
> + return EFI_INVALID_PARAMETER;
> + }
> +
> + if (fwu_empty_capsule(capsule_data)) {
> + capsule_update = false;
> + return fwu_empty_capsule_process(capsule_data);
> + } else {
> + capsule_update = true;
> + }
> +
> + /* Obtain the update_index from the platform */
> + status = fwu_plat_get_update_index(&update_index);
> + if (status < 0) {
> + log_err("Failed to get the FWU update_index value\n");
> + return EFI_DEVICE_ERROR;
> + }
> +
> + fw_accept_os = capsule_data->flags & FW_ACCEPT_OS ? 0x1 : 0x0;
> + /*
> + * For Multi Bank updates, the image index is determined at
> + * runtime based on the value of the update bank.
> + */
> + image_index_check = false;
> + }
>
> /* sanity check */
> if (capsule_data->header_size < sizeof(*capsule) ||
> @@ -485,8 +607,31 @@ static efi_status_t efi_capsule_update_firmware(
> goto out;
> }
>
> + if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> + /*
> + * Based on the value of update_image_type_id,
> + * derive the alt number value. This will be
> + * passed as update_image_index to the
> + * set_image function.
> + */
> + image_type_id = image->update_image_type_id;
> + status = fwu_get_image_alt_num(&image_type_id,
> + update_index,
> + &alt_no);

I have a concern here.
The function's name, fwd_get_image_alt_num(), suggests that it is somehow
related to dfu (alto number) feature. Actually, however, I hope not;
the function's purpose is simply to convert "update_index" to a proper
value under some condition (i.e. A/B update).

From design's point of view, the entire code in efi_capsule.c should
stay generic enough to support various type of underling firmware frameworks.
Please note that efi_firmware.c is just one of such implementations of
firmware update protocols.

So please think of changing the function's name if I am correct.

Furthermore, it would be better to call fwu_get_image_alt_num() in
FMP drivers (in this case, efi_firmware.c). (Not sure though)

> + ret = fwu_to_efi_error(status);
> + if (ret != EFI_SUCCESS) {
> + log_err("Unable to get the alt no for the image type %pUs\n",
> + &image_type_id);
> + goto out;
> + }
> + log_debug("alt_no %u for Image Type Id %pUs\n",
> + alt_no, &image_type_id);
> + image_index = alt_no + 1;
> + } else {
> + image_index = image->update_image_index;
> + }
> abort_reason = NULL;
> - ret = EFI_CALL(fmp->set_image(fmp, image->update_image_index,
> + ret = EFI_CALL(fmp->set_image(fmp, image_index,
> image_binary,
> image_binary_size,
> vendor_code, NULL,
> @@ -497,6 +642,33 @@ static efi_status_t efi_capsule_update_firmware(
> efi_free_pool(abort_reason);
> goto out;
> }
> +
> + if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> + if (!fw_accept_os) {
> + /*
> + * The OS will not be accepting the firmware
> + * images. Set the accept bit of all the
> + * images contained in this capsule.
> + */
> + status = fwu_accept_image(&image_type_id,
> + update_index);
> + } else {
> + status = fwu_clear_accept_image(&image_type_id,
> + update_index);
> + }
> + ret = fwu_to_efi_error(status);
> + if (ret != EFI_SUCCESS) {
> + log_err("Unable to %s the accept bit for the image %pUs\n",
> + fw_accept_os ? "clear" : "set",
> + &image_type_id);
> + goto out;
> + }
> +
> + log_debug("%s the accepted bit for Image %pUs\n",
> + fw_accept_os ? "Cleared" : "Set",
> + &image_type_id);
> + }
> +
> }
>
> out:
> @@ -1102,8 +1274,10 @@ efi_status_t efi_launch_capsules(void)
> {
> struct efi_capsule_header *capsule = NULL;
> u16 **files;
> + int status;
> unsigned int nfiles, index, i;
> efi_status_t ret;
> + bool update_status = true;
>
> if (check_run_capsules() != EFI_SUCCESS)
> return EFI_SUCCESS;
> @@ -1131,12 +1305,14 @@ efi_status_t efi_launch_capsules(void)
> ret = efi_capsule_read_file(files[i], &capsule);
> if (ret == EFI_SUCCESS) {
> ret = efi_capsule_update_firmware(capsule);
> - if (ret != EFI_SUCCESS)
> + if (ret != EFI_SUCCESS) {
> log_err("Applying capsule %ls failed.\n",
> files[i]);
> - else
> + update_status = false;
> + } else {
> log_info("Applying capsule %ls succeeded.\n",
> files[i]);
> + }
>
> /* create CapsuleXXXX */
> set_capsule_result(index, capsule, ret);
> @@ -1144,6 +1320,7 @@ efi_status_t efi_launch_capsules(void)
> free(capsule);
> } else {
> log_err("Reading capsule %ls failed\n", files[i]);
> + update_status = false;
> }
> /* delete a capsule either in case of success or failure */
> ret = efi_capsule_delete_file(files[i]);
> @@ -1151,7 +1328,33 @@ efi_status_t efi_launch_capsules(void)
> log_err("Deleting capsule %ls failed\n",
> files[i]);
> }
> +
> efi_capsule_scan_done();
> + if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> + if (update_status == true && capsule_update == true) {
> + /*
> + * All the capsules have been updated successfully,
> + * update the FWU metadata.
> + */
> + log_debug("Update Complete. Now updating active_index to %u\n",
> + update_index);
> + status = fwu_update_active_index(update_index);
> + ret = fwu_to_efi_error(status);
> + if (ret != EFI_SUCCESS) {
> + log_err("Failed to update FWU metadata index values\n");
> + } else {
> + log_debug("Successfully updated the active_index\n");
> + ret = EFI_SUCCESS;
> + if (fw_accept_os) {
> + status = fwu_trial_state_ctr_start();
> + if (status < 0)
> + ret = EFI_DEVICE_ERROR;
> + }
> + }
> + } else if (capsule_update == true && update_status == false) {
> + log_err("All capsules were not updated. Not updating FWU metadata\n");
> + }
> + }
>
> for (i = 0; i < nfiles; i++)
> free(files[i]);
> diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
> index 23dc7a0710..60012e873e 100644
> --- a/lib/efi_loader/efi_setup.c
> +++ b/lib/efi_loader/efi_setup.c
> @@ -351,7 +351,8 @@ efi_status_t efi_init_obj_list(void)
> goto out;
>
> /* Execute capsules after reboot */
> - if (IS_ENABLED(CONFIG_EFI_CAPSULE_ON_DISK) &&
> + if (!IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE) &&

Why do you need this?

> + IS_ENABLED(CONFIG_EFI_CAPSULE_ON_DISK) &&
> !IS_ENABLED(CONFIG_EFI_CAPSULE_ON_DISK_EARLY))
> ret = efi_launch_capsules();
> out:
> diff --git a/lib/fwu_updates/Kconfig b/lib/fwu_updates/Kconfig
> new file mode 100644
> index 0000000000..e33085f1d3
> --- /dev/null
> +++ b/lib/fwu_updates/Kconfig
> @@ -0,0 +1,32 @@
> +config FWU_MULTI_BANK_UPDATE
> + bool "Enable FWU Multi Bank Update Feature"
> + depends on EFI_HAVE_CAPSULE_SUPPORT

As a matter of fact, your commits rely on CAPSULE_ON_DISK.

> + select PARTITION_TYPE_GUID
> + select EFI_SETUP_EARLY

This kconfig is always on since the commit a9bf024b2933
(efi_loader: disk: a helper function to create efi_disk objects from udevice).

Do you want to enable CAPSULE_ON_DISK_EARLY?

-Takahiro Akashi

> + select EVENT
> + help
> + Feature for updating firmware images on platforms having
> + multiple banks(copies) of the firmware images. One of the
> + bank is selected for updating all the firmware components
> +
> +config FWU_NUM_BANKS
> + int "Number of Banks defined by the platform"
> + depends on FWU_MULTI_BANK_UPDATE
> + help
> + Define the number of banks of firmware images on a platform
> +
> +config FWU_NUM_IMAGES_PER_BANK
> + int "Number of firmware images per bank"
> + depends on FWU_MULTI_BANK_UPDATE
> + help
> + Define the number of firmware images per bank. This value
> + should be the same for all the banks.
> +
> +config FWU_TRIAL_STATE_CNT
> + int "Number of times system boots in Trial State"
> + depends on FWU_MULTI_BANK_UPDATE
> + default 3
> + help
> + With FWU Multi Bank Update feature enabled, number of times
> + the platform is allowed to boot in Trial State after an
> + update.
> diff --git a/lib/fwu_updates/Makefile b/lib/fwu_updates/Makefile
> new file mode 100644
> index 0000000000..1993088e5b
> --- /dev/null
> +++ b/lib/fwu_updates/Makefile
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +#
> +# Copyright (c) 2022, Linaro Limited
> +#
> +
> +obj-$(CONFIG_FWU_MULTI_BANK_UPDATE) += fwu.o
> +obj-$(CONFIG_FWU_MDATA_GPT_BLK) += fwu_gpt.o
> diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c
> index 27f48855af..de2412785d 100644
> --- a/lib/fwu_updates/fwu.c
> +++ b/lib/fwu_updates/fwu.c
> @@ -513,7 +513,30 @@ u8 fwu_update_checks_pass(void)
> return !trial_state && boottime_check;
> }
>
> +/**
> + * fwu_trial_state_ctr_start() - Start the Trial State counter
> + *
> + * Start the counter to identify the platform booting in the
> + * Trial State. The counter is implemented as an EFI variable.
> + *
> + * Return: 0 if OK, -ve on error
> + *
> + */
> +int fwu_trial_state_ctr_start(void)
> +{
> + int ret;
> + u16 trial_state_ctr;
> +
> + trial_state_ctr = 0;
> + ret = trial_counter_update(&trial_state_ctr);
> + if (ret)
> + log_err("Unable to initialise TrialStateCtr\n");
> +
> + return ret;
> +}
> +
> static int fwu_boottime_checks(void *ctx, struct event *event)
> +
> {
> int ret;
> struct udevice *dev;
> --
> 2.34.1
>