Merge patch series "bootstd: Add Android support"

Mattijs Korpershoek <[email protected]> says:

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[email protected]/
[6] https://software-dl.ti.com/processor-sdk-android/esd/AM62X/09_02_00/docs/android/Overview.html

diff --combined boot/Kconfig
index 95300b008c5dfb325dfa4072f5ed4d2127d7ce1e,4a17deaa3e24d0cbbb33461e5e7c2ffd4ce0dafe..def483a41f156c0df9446f50f8ed20439f6d075f
--- 1/boot/Kconfig
--- 2/boot/Kconfig
+++ b/boot/Kconfig
@@@ -494,6 -494,23 +494,23 @@@ config BOOTMETH_GLOBA
          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
+       depends on CMDLINE
+       select ANDROID_AB
+       select ANDROID_BOOT_IMAGE
+       select CMD_BCB
+       select CMD_FASTBOOT
+       select PARTITION_TYPE_GUID
+       select PARTITION_UUIDS
+       help
+         Enables support for booting Android using bootstd. Android requires
+         multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
+ 
+         Note that only MMC bootdevs are supported at present. This is caused
+         by AVB being limited to MMC devices only.
+ 
  config BOOTMETH_CROS
        bool "Bootdev support for Chromium OS"
        depends on X86 || ARM || SANDBOX
@@@ -816,7 -833,7 +833,7 @@@ choic
        prompt "Freescale PBL (or predecessor) load location"
        depends on RAMBOOT_PBL || ((TARGET_P1010RDB_PA || TARGET_P1010RDB_PB \
                || TARGET_P1020RDB_PC || TARGET_P1020RDB_PD || TARGET_P2020RDB) \
 -              && !CMD_NAND)
 +              && !CMD_NAND) || (TARGET_TURRIS_1X && SYS_MPC85XX_NO_RESETVEC)
  
  config SDCARD
        bool "Freescale PBL (or similar) is found on SD card"

diff --combined configs/sandbox_defconfig
index e2db66d4a25b2e7cd5768250e6ce01a290c99250,36e43e0e21ab8416394a18dc8f5df99138fc5c63..dc5fcdbd1c9ebbb3cd8577a4b14ed7f651d17294
--- 1/configs/sandbox_defconfig
--- 2/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@@ -15,6 -15,7 +15,7 @@@ CONFIG_FIT=
  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 +41,6 @@@ CONFIG_LOG_MAX_LEVEL=
  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
@@@ -353,7 -353,7 +353,7 @@@ CONFIG_EFI_RUNTIME_UPDATE_CAPSULE=
  CONFIG_EFI_CAPSULE_ON_DISK=y
  CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y
  CONFIG_EFI_CAPSULE_AUTHENTICATE=y
 -CONFIG_EFI_CAPSULE_ESL_FILE="board/sandbox/capsule_pub_esl_good.esl"
 +CONFIG_EFI_CAPSULE_CRT_FILE="board/sandbox/capsule_pub_key_good.crt"
  CONFIG_EFI_SECURE_BOOT=y
  CONFIG_TEST_FDTDEC=y
  CONFIG_UNIT_TEST=y