Update the Android documentation to describe version 3 and 4 of boot image header.
Signed-off-by: Safae Ouajih souajih@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-bo...