[PATCH 0/6] bootstd: Add Android support
Mattijs Korpershoek
mkorpershoek at baylibre.com
Thu Jun 6 14:23:52 CEST 2024
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 at 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 at baylibre.com>
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