u-boot.git/boot/bootmeth_android.h, branch v2026.04 Unnamed repository; edit this file 'description' to name the repository. bootstd: Add a bootmeth for Android 2024-07-18T19:51:30+00:00 Mattijs Korpershoek mkorpershoek@baylibre.com 2024-07-10T08:40:05+00:00 125d9f3306ea4bc8888dc991ae3aa87327b0d522 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/ Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Julien Masson <jmasson@baylibre.com> Tested-by: Guillaume La Roque <glaroque@baylibre.com> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com> 
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/

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Julien Masson <jmasson@baylibre.com>
Tested-by: Guillaume La Roque <glaroque@baylibre.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>