Re: [PATCH 2/6] bootstd: android: add non-A/B image support

[Mattijs Korpershoek <mkorpershoek@baylibre.com>]

Hi Guillaume,

Thank you for the patch.

On jeu., oct. 17, 2024 at 18:10, Guillaume La Roque <glaroque@baylibre.com> wrote:

> Update android bootmeth to support non-A/B image.
> Enable AB support only when ANDROID_AB is enabled.
>
> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
> ---
>  boot/Kconfig                     |  1 -
>  boot/bootmeth_android.c          | 53 ++++++++++++++++++++++++++++++++++------
>  configs/am62x_a53_android.config |  1 +
>  configs/sandbox_defconfig        |  1 +
>  4 files changed, 47 insertions(+), 9 deletions(-)
>
> diff --git a/boot/Kconfig b/boot/Kconfig
> index 1d50a83a2d2f..fa0739ff05dd 100644
> --- a/boot/Kconfig
> +++ b/boot/Kconfig
> @@ -500,7 +500,6 @@ config BOOTMETH_ANDROID
>  	bool "Bootdev support for Android"
>  	depends on X86 || ARM || SANDBOX
>  	depends on CMDLINE
> -	select ANDROID_AB
>  	select ANDROID_BOOT_IMAGE
>  	select CMD_BCB
>  	imply CMD_FASTBOOT
> diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c
> index 2e7f85e4a708..8fa4952df3f2 100644
> --- a/boot/bootmeth_android.c
> +++ b/boot/bootmeth_android.c
> @@ -29,6 +29,7 @@
>  #define BCB_PART_NAME "misc"
>  #define BOOT_PART_NAME "boot"
>  #define VENDOR_BOOT_PART_NAME "vendor_boot"
> +#define SLOT_LEN 2
>  
>  /**
>   * struct android_priv - Private data
> @@ -42,7 +43,7 @@
>   */
>  struct android_priv {
>  	enum android_boot_mode boot_mode;
> -	char slot[2];
> +	char *slot;
>  	u32 header_version;
>  };
>  
> @@ -71,7 +72,11 @@ static int scan_boot_part(struct udevice *blk, struct android_priv *priv)
>  	char *buf;
>  	int ret;
>  
> -	sprintf(partname, BOOT_PART_NAME "_%s", priv->slot);
> +	if (priv->slot)
> +		sprintf(partname, BOOT_PART_NAME "_%s", priv->slot);
> +	else
> +		sprintf(partname, BOOT_PART_NAME);
> +
>  	ret = part_get_info_by_name(desc, partname, &partition);
>  	if (ret < 0)
>  		return log_msg_ret("part info", ret);
> @@ -108,7 +113,11 @@ static int scan_vendor_boot_part(struct udevice *blk, struct android_priv *priv)
>  	char *buf;
>  	int ret;
>  
> -	sprintf(partname, VENDOR_BOOT_PART_NAME "_%s", priv->slot);
> +	if (priv->slot)
> +		sprintf(partname, VENDOR_BOOT_PART_NAME "_%s", priv->slot);
> +	else
> +		sprintf(partname, VENDOR_BOOT_PART_NAME);
> +
>  	ret = part_get_info_by_name(desc, partname, &partition);
>  	if (ret < 0)
>  		return log_msg_ret("part info", ret);
> @@ -142,6 +151,11 @@ static int android_read_slot_from_bcb(struct bootflow *bflow, bool decrement)
>  	char slot_suffix[3];
>  	int ret;
>  
> +	if (!CONFIG_IS_ENABLED(ANDROID_AB)) {
> +		priv->slot = NULL;
> +		return 0;
> +	}
> +
>  	ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
>  	if (ret < 0)
>  		return log_msg_ret("part", ret);
> @@ -150,6 +164,7 @@ static int android_read_slot_from_bcb(struct bootflow *bflow, bool decrement)
>  	if (ret < 0)
>  		return log_msg_ret("slot", ret);
>  
> +	priv->slot = malloc(SLOT_LEN);
>  	priv->slot[0] = BOOT_SLOT_NAME(ret);
>  	priv->slot[1] = '\0';
>  
> @@ -274,7 +289,7 @@ static int android_read_bootflow(struct udevice *dev, struct bootflow *bflow)
>  	configure_serialno(bflow);
>  	configure_bootloader_version(bflow);
>  
> -	if (priv->boot_mode == ANDROID_BOOT_MODE_NORMAL) {
> +	if (priv->boot_mode == ANDROID_BOOT_MODE_NORMAL && priv->slot) {
>  		ret = bootflow_cmdline_set_arg(bflow, "androidboot.force_normal_boot",
>  					       "1", false);
>  		if (ret < 0) {
> @@ -323,14 +338,24 @@ static int read_slotted_partition(struct blk_desc *desc, const char *const name,
>  {
>  	struct disk_partition partition;
>  	char partname[PART_NAME_LEN];
> +	int partname_len;

Should be size_t since we compare it with the output of strlen().

>  	int ret;
>  	u32 n;
>  
>  	/* Ensure name fits in partname it should be: <name>_<slot>\0 */

The comment is not valid for non A/B. Maybe we can update it?

/*
 * Ensure name fits in partname.
 * For A/B, it should be <name>_<slot>\0
 * For non A/B, it should be <name>\0
 */

> -	if (strlen(name) > (PART_NAME_LEN - 2 - 1))
> +	if (CONFIG_IS_ENABLED(ANDROID_AB))
> +		partname_len = PART_NAME_LEN - 2 - 1;
> +	else
> +		partname_len = PART_NAME_LEN - 1;
> +
> +	if (strlen(name) > partname_len)
>  		return log_msg_ret("name too long", -EINVAL);
>  
> -	sprintf(partname, "%s_%s", name, slot);
> +	if (slot)
> +		sprintf(partname, "%s_%s", name, slot);
> +	else
> +		sprintf(partname, "%s", name);
> +
>  	ret = part_get_info_by_name(desc, partname, &partition);
>  	if (ret < 0)
>  		return log_msg_ret("part", ret);
> @@ -382,7 +407,7 @@ static int run_avb_verification(struct bootflow *bflow)
>  	AvbSlotVerifyData *out_data;
>  	enum avb_boot_state boot_state;
>  	char *extra_args;
> -	char slot_suffix[3];
> +	char *slot_suffix = "";

Why are we making this a char *?

Can't we keep slot_suffix[3] = ""; instead ?

It should work similarly and avoids using malloc() and free()
for a local variable.

>  	bool unlocked = false;
>  	int ret;
>  
> @@ -390,7 +415,10 @@ static int run_avb_verification(struct bootflow *bflow)
>  	if (!avb_ops)
>  		return log_msg_ret("avb ops", -ENOMEM);
>  
> -	sprintf(slot_suffix, "_%s", priv->slot);
> +	if (priv->slot) {
> +		slot_suffix = malloc(3);
> +		sprintf(slot_suffix, "_%s", priv->slot);
> +	}
>  
>  	ret = avb_ops->read_is_device_unlocked(avb_ops, &unlocked);
>  	if (ret != AVB_IO_RESULT_OK)
> @@ -427,12 +455,18 @@ static int run_avb_verification(struct bootflow *bflow)
>  	if (ret < 0)
>  		goto free_out_data;
>  
> +	if (priv->slot)
> +		free(slot_suffix);
> +
>  	return 0;
>  
>   free_out_data:
>  	if (out_data)
>  		avb_slot_verify_data_free(out_data);
>  
> +	if (priv->slot)
> +		free(slot_suffix);
> +
>  	return log_msg_ret("avb cmdline", ret);
>  }
>  #else
> @@ -480,6 +514,9 @@ static int boot_android_normal(struct bootflow *bflow)
>  	}
>  	set_abootimg_addr(loadaddr);
>  
> +	if (priv->slot)
> +		free(priv->slot);
> +
>  	ret = bootm_boot_start(loadaddr, bflow->cmdline);
>  
>  	return log_msg_ret("boot", ret);
> diff --git a/configs/am62x_a53_android.config b/configs/am62x_a53_android.config
> index adbe2b8e126f..2aca51e3a107 100644
> --- a/configs/am62x_a53_android.config
> +++ b/configs/am62x_a53_android.config
> @@ -11,6 +11,7 @@ CONFIG_RANDOM_UUID=y # Needed for FASTBOOT_CMD_OEM_FORMAT
>  CONFIG_FASTBOOT_CMD_OEM_FORMAT=y
>  # Enable Android boot flow
>  CONFIG_BOOTMETH_ANDROID=y
> +CONFIG_ANDROID_AB=y
>  CONFIG_SYS_BOOTM_LEN=0x4000000
>  CONFIG_SYS_MALLOC_LEN=0x08000000
>  CONFIG_AVB_VERIFY=y
> diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
> index d111858082d5..6b8dedf20712 100644
> --- a/configs/sandbox_defconfig
> +++ b/configs/sandbox_defconfig
> @@ -50,6 +50,7 @@ CONFIG_LOG_DEFAULT_LEVEL=6
>  CONFIG_LOGF_FUNC=y
>  CONFIG_DISPLAY_BOARDINFO_LATE=y
>  CONFIG_STACKPROTECTOR=y
> +CONFIG_ANDROID_AB=y
>  CONFIG_CMD_CPU=y
>  CONFIG_CMD_LICENSE=y
>  CONFIG_CMD_SMBIOS=y
>
> -- 
> 2.34.1