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authorSafae Ouajih <souajih@baylibre.com>2023-02-06 00:50:19 +0100
committerTom Rini <trini@konsulko.com>2023-04-04 14:50:47 -0400
commit3e7b71c7286b8e12891c4fd954c21ed8be018de7 (patch)
tree1bff390db16aa7882b8b0427563e687d10736139 /doc
parent57e405e1f4745cdca49a4a6b260afe68592b1d5c (diff)
downloadu-boot-3e7b71c7286b8e12891c4fd954c21ed8be018de7.tar.gz
doc: android: add documentation for v3, v4 boot image header
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>
Diffstat (limited to 'doc')
-rw-r--r--doc/android/boot-image.rst13
1 files changed, 12 insertions, 1 deletions
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