fdt: Add support for a separate device tree (CONFIG_OF_SEPARATE)

This adds support for an FDT to be build as a separate binary file called
u-boot.dtb. This can be concatenated with the U-Boot binary to provide a
device tree located at run-time by U-Boot. The Makefile is modified to
provide this file in u-boot-dtb.bin.

Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Simon Glass 2011-10-24 19:15:31 +00:00 committed by Wolfgang Denk
parent bbb0b128c3
commit 2c0f79e44b
3 changed files with 23 additions and 2 deletions

1
.gitignore vendored
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@ -35,6 +35,7 @@
/u-boot.dis
/u-boot.lds
/u-boot.ubl
/u-boot.dtb
#
# Generated files

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@ -359,9 +359,17 @@ ALL-$(CONFIG_ONENAND_U_BOOT) += $(obj)u-boot-onenand.bin
ONENAND_BIN ?= $(obj)onenand_ipl/onenand-ipl-2k.bin
ALL-$(CONFIG_MMC_U_BOOT) += $(obj)mmc_spl/u-boot-mmc-spl.bin
ALL-$(CONFIG_SPL) += $(obj)spl/u-boot-spl.bin
ALL-$(CONFIG_OF_SEPARATE) += $(obj)u-boot.dtb $(obj)u-boot-dtb.bin
all: $(ALL-y) $(SUBDIR_EXAMPLES)
$(obj)u-boot.dtb: $(obj)u-boot
$(MAKE) -C dts binary
mv $(obj)dts/dt.dtb $@
$(obj)u-boot-dtb.bin: $(obj)u-boot.bin $(obj)u-boot.dtb
cat $^ >$@
$(obj)u-boot.hex: $(obj)u-boot
$(OBJCOPY) ${OBJCFLAGS} -O ihex $< $@

16
README
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@ -824,8 +824,8 @@ The following options need to be configured:
experimental and only available on a few boards. The device
tree is available in the global data as gd->fdt_blob.
U-Boot needs to get its device tree from somewhere. At present
the only way is to embed it in the image with CONFIG_OF_EMBED.
U-Boot needs to get its device tree from somewhere. This can
be done using one of the two options below:
CONFIG_OF_EMBED
If this variable is defined, U-Boot will embed a device tree
@ -834,6 +834,18 @@ The following options need to be configured:
is then picked up in board_init_f() and made available through
the global data structure as gd->blob.
CONFIG_OF_SEPARATE
If this variable is defined, U-Boot will build a device tree
binary. It will be called u-boot.dtb. Architecture-specific
code will locate it at run-time. Generally this works by:
cat u-boot.bin u-boot.dtb >image.bin
and in fact, U-Boot does this for you, creating a file called
u-boot-dtb.bin which is useful in the common case. You can
still use the individual files if you need something more
exotic.
- Watchdog:
CONFIG_WATCHDOG
If this variable is defined, it enables watchdog