Difuse/u-boot
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

doc: android: add documentation for v3, v4 boot image header

Browse source 
Update the Android documentation to describe version 3 and 4 of boot
image header.

Signed-off-by: Safae Ouajih <souajih@baylibre.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
This commit is contained in:
Safae Ouajih 2023-02-06 00:50:19 +01:00 committed by Tom Rini
parent 57e405e1f4
commit 3e7b71c728
1 changed files with 12 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
doc/android/boot-image.rst
View file

@ -27,11 +27,21 @@ next image headers:
* v2: used in devices launched with Android 10; adds ``dtb`` field, which
references payload containing DTB blobs (either concatenated one after the
other, or in Android DTBO image format)
* v3: used in devices launched with Android 11; adds ``vendor_boot`` partition
and removes the second-stage bootloader and recovery image support. The new
``vendor_boot`` partition holds the device tree blob (DTB) and a vendor ramdisk.
The generic ramdisk in ``boot`` partition is loaded immediately following
the vendor ramdisk.
* v4: used in devices launched with Android 12; provides a boot signature in boot
image header, supports multiple vendor ramdisk fragments in ``vendor_boot``
partition. This version also adds a bootconfig section at the end of the vendor
boot image, this section contains boot configuration parameters known at build time
(see [9]_ for details).
v2, v1 and v0 formats are backward compatible.
The Android Boot Image format is represented by
:c:type:`struct andr_img_hdr <andr_img_hdr>` in U-Boot, and can be seen in
:c:type:`struct andr_image_data <andr_image_data>` in U-Boot, and can be seen in
``include/android_image.h``. U-Boot supports booting Android Boot Image and also
has associated command
@ -153,3 +163,4 @@ References
.. [6] :doc:`avb2`
.. [7] https://source.android.com/devices/bootloader
.. [8] https://connect.linaro.org/resources/san19/san19-217/
.. [9] https://source.android.com/docs/core/architecture/bootloader/implementing-bootconfig