diff options
| author | Alex Deymo <deymo@google.com> | 2017-04-02 01:25:20 -0700 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2017-05-09 20:35:06 -0400 |
| commit | 82f766d1d2c580a29bed340ea4dd9fa1b8ff05e0 (patch) | |
| tree | 81c70f6e469d4431d3852e2d6fe43443fff6ad5a /doc | |
| parent | 45a6d231b2f9b891a7df517fc40b8466e12f2b57 (diff) | |
Allow boards to initialize the DT at runtime.
In some boards like the Raspberry Pi the initial bootloader will pass
a DT to the kernel. When using U-Boot as such kernel, the board code in
U-Boot should be able to provide U-Boot with this, already assembled
device tree blob.
This patch introduces a new config option CONFIG_OF_BOARD to use instead
of CONFIG_OF_EMBED or CONFIG_OF_SEPARATE which will initialize the DT
from a board-specific funtion instead of bundling one with U-Boot or as
a separated file. This allows boards like the Raspberry Pi to reuse the
device tree passed from the bootcode.bin and start.elf firmware
files, including the run-time selected device tree overlays.
Signed-off-by: Alex Deymo <deymo@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.fdt-control | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/doc/README.fdt-control b/doc/README.fdt-control index c9656299053..378b06b108d 100644 --- a/doc/README.fdt-control +++ b/doc/README.fdt-control @@ -130,6 +130,10 @@ u-boot-dtb.bin which does the above step for you also. If you are using CONFIG_SPL_FRAMEWORK, then u-boot.img will be built to include the device tree binary. +If CONFIG_OF_BOARD is defined, a board-specific routine will provide the +device tree at runtime, for example if an earlier bootloader stage creates +it and passes it to U-Boot. + If CONFIG_OF_HOSTFILE is defined, then it will be read from a file on startup. This is only useful for sandbox. Use the -d flag to U-Boot to specify the file to read. |