ARM: Distro boot: document the need for fdtfile variable to be set
When testing builds provided in https://github.com/openwrt/openwrt/pull/3360
I discovered that fdtfile was not set and as a result the firmware was not
functional. So I am documenting what is needed.
Signed-off-by: Dennis Gilmore <dennis@ausil.us>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Cc: Tom Rini <trini@konsulko.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Vagrant Cascadian <vagrant@debian.org>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Karsten Merker <merker@debian.org>
diff --git a/doc/README.distro b/doc/README.distro
index 5076beb..cc1c41e 100644
--- a/doc/README.distro
+++ b/doc/README.distro
@@ -224,6 +224,17 @@
A size of 1MB for the FDT/DTB seems reasonable.
+fdtfile:
+
+ Mandatory. the name of the DTB file for the specific board for instance
+ the espressobin v5 board the value is "marvell/armada-3720-espressobin.dtb"
+ while on a clearfog pro it is "armada-388-clearfog-pro.dtb" in the case of
+ a board providing its firmware based DTB this value can be used to override
+ the DTB with a different DTB. fdtfile will automatically be set for you if
+ it matches the format ${soc}-${board}.dtb which covers most 32 bit use cases.
+ AArch64 generally does not match as the Linux kernel put the dtb files under
+ SoC vendor directories.
+
ramdisk_addr_r:
Mandatory. The location in RAM where the initial ramdisk will be loaded to