Hi Mattijs, On Thu, 13 Jun 2024 at 04:13, Mattijs Korpershoek <mkorpersh...@baylibre.com> wrote: > > 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-...@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 <mkorpersh...@baylibre.com> > --- > Changes in v2: > - Dropped patch 2/6 boot: android: Add image_android_get_version() (Igor) > - Fixed multi-line comment style (Igor, Simon) > - Added dependency on CMD_FASTBOOT for BOOTMETH_ANDROID (Igor) > - Fixed various resource leaks (Igor) > - Fixed bootmeth_priv dangling pointer on error cases (Igor) > - Updated test instructions in commit message for patch 6/6 > - Added __weak impl of get_avendor_bootimg_addr() in patch 1 (dropped > Igor's review because of this change) > - Added extra info in Kconfig to detail MMC limitation (Simon) > - Fixed typo Bootmethod->Bootmeth (Simon) > - Documented android_priv structure (Simon) > - Demoted various messages from printf() to log_debug (Simon) > - Fixed some lines too long (Simon) > - Added function documentation to read_slotted_partition() (Simon) > - Added some doc about avb extra_args being modified (Simon) > - Link to v1: > https://lore.kernel.org/r/20240606-bootmeth-android-v1-0-0c69d4457...@baylibre.com > > --- > Mattijs Korpershoek (5): > boot: android: Provide vendor_bootimg_addr in boot_get_fdt() > 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 | 16 ++ > boot/Makefile | 2 + > boot/bootflow.c | 12 + > boot/bootmeth_android.c | 553 > ++++++++++++++++++++++++++++++++++++++++++++++ > boot/bootmeth_android.h | 29 +++ > boot/image-android.c | 5 + > 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 | 14 ++ > test/boot/bootflow.c | 65 +++++- > test/py/tests/test_ut.py | 76 +++++++ > 16 files changed, 811 insertions(+), 5 deletions(-) > --- > base-commit: f9886bc60f42d5bcfcfa4e474af7dc230400b6be > change-id: 20240605-bootmeth-android-bfc8596e9367 > > Best regards, > -- > Mattijs Korpershoek <mkorpersh...@baylibre.com> >
Thinking about this, I believe we should start having docs about the individual bootmeths themselves. Can you add a section about your new bootmeth? I will come up with a patch for the others that I know about. Perhaps doc/develop/bootstd.rst would be a suitable place for now? Regards, Simon
