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authorAlex Deymo2017-04-02 01:25:20 -0700
committerTom Rini2017-05-09 20:35:06 -0400
commit82f766d1d2c580a29bed340ea4dd9fa1b8ff05e0 (patch)
tree81c70f6e469d4431d3852e2d6fe43443fff6ad5a /README
parent45a6d231b2f9b891a7df517fc40b8466e12f2b57 (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 'README')
-rw-r--r--README8
1 files changed, 7 insertions, 1 deletions
diff --git a/README b/README
index 78173e2d867..685a8222b0d 100644
--- a/README
+++ b/README
@@ -968,7 +968,7 @@ The following options need to be configured:
tree is available in the global data as gd->fdt_blob.
U-Boot needs to get its device tree from somewhere. This can
- be done using one of the two options below:
+ be done using one of the three options below:
CONFIG_OF_EMBED
If this variable is defined, U-Boot will embed a device tree
@@ -989,6 +989,12 @@ The following options need to be configured:
still use the individual files if you need something more
exotic.
+ CONFIG_OF_BOARD
+ If this variable is defined, U-Boot will use the device tree
+ provided by the board at runtime instead of embedding one with
+ the image. Only boards defining board_fdt_blob_setup() support
+ this option (see include/fdtdec.h file).
+
- Watchdog:
CONFIG_WATCHDOG
If this variable is defined, it enables watchdog