[PATCH v2 0/5] bootstd: Add Android support

[Simon Glass]

Hi Mattijs,

On Mon, 17 Jun 2024 at 09:15, Mattijs Korpershoek
<mkorpershoek at baylibre.com> wrote:
>
> Hi Simon,
>
> On lun., juin 17, 2024 at 07:53, Simon Glass <sjg at chromium.org> wrote:
>
> > Hi Mattijs,
> >
> > On Thu, 13 Jun 2024 at 04:13, Mattijs Korpershoek
> > <mkorpershoek at 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-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>
> >> ---
> >> 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-v1-0-0c69d4457cc5@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 <mkorpershoek at baylibre.com>
> >>
> >
> > Thinking about this, I believe we should start having docs about the
> > individual bootmeths themselves.
>
> Yes.
>
> >
> > 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?
>
> Yes I can add a section. I would have preferred to have an example to
> work from there, but I can start writing docs as well.
>
> I'm leaving on vacation soon (without computer), so I'll be able to
> send a v3 with docs included in at earliest a 2-3 weeks from now.

It isn't a blocker for this series, just something I thought of.

>
> If you make a patch for the other bootmeths in the mean-time, please cc
> me so that I can help review and have an example for Android.

Yes, will do, if I do.

Regards,
Simon