[PATCH v3 17/19] doc: android: add documentation for v3,v4 boot image header

[Mattijs Korpershoek]

On lun., févr. 06, 2023 at 00:50, Safae Ouajih <souajih at baylibre.com> wrote:

> Update the Android documentation to describe version 3 and 4 of boot
> image header.
>
> Signed-off-by: Safae Ouajih <souajih at baylibre.com>
> ---

Reviewed-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>

>  doc/android/boot-image.rst | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/doc/android/boot-image.rst b/doc/android/boot-image.rst
> index 71db02521b..c719b4d711 100644
> --- a/doc/android/boot-image.rst
> +++ b/doc/android/boot-image.rst
> @@ -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
> -- 
> 2.34.1