[PATCH] ARM: supply a DTB file to be appended
From: Rob Herring <hidden>
Date: 2011-09-09 04:52:07
Also in:
linux-devicetree
Linus, On 09/08/2011 05:14 AM, Linus Walleij wrote:
From: Linus Walleij <redacted> This adds a Kconfig string where you can specify a file to be appended to the zImage on build, then auto-appends it. The idea is to mimic how we supply an initramfs image by a similar parameter.
The key difference is an initramfs is much more likely to be platform independent, but a dtb will never be. Once we have a single kernel, then we'll need a way to include multiple dtbs and logic to select one? I think appending a dtb in a way that can be done as late as possible (i.e. kernel rootfs install time) is a much more useful feature. Rob
quoted hunk
This makes it easy to script the kernel build with different device trees, and it also vastly simplifies building uImages since "make uImage" will now pick up the devcie tree and include it in the final image as part of the build process. Cc: Nicolas Pitre <redacted> Cc: David Brown <redacted> Cc: Niklas Hernaeus <redacted> Cc: Grant Likely <redacted> Signed-off-by: Linus Walleij <redacted> --- This builds on top of Nicos pending appended device tree patches. Nico, if this gains some liking, please include it in your series. --- arch/arm/Kconfig | 10 ++++++++++ arch/arm/boot/Makefile | 8 +++++++- 2 files changed, 17 insertions(+), 1 deletions(-)diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4ea9974..cb8ee68 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig@@ -1789,6 +1789,16 @@ config ARM_APPENDED_DTB (dtb) appended to zImage (e.g. cat zImage <filename>.dtb > zImage_w_dtb). +config ARM_APPENDED_DTB_FILE + string "DTB file" + depends on ARM_APPENDED_DTB + default "" + help + This gives the name of file from the build directory to append + to the zImage after it has been built. + + If you are not sure, leave it blank. + config ARM_ATAG_DTB_COMPAT bool "Supplement the appended DTB with traditional ATAG information" depends on ARM_APPENDED_DTBdiff --git a/arch/arm/boot/Makefile b/arch/arm/boot/Makefile index a1edfd5..5ab6abf 100644 --- a/arch/arm/boot/Makefile +++ b/arch/arm/boot/Makefile@@ -53,8 +53,14 @@ $(obj)/Image: vmlinux FORCE $(obj)/compressed/vmlinux: $(obj)/Image FORCE $(Q)$(MAKE) $(build)=$(obj)/compressed $@ -$(obj)/zImage: $(obj)/compressed/vmlinux FORCE +# Rule to optionally append a DTB +dtbfile := $(shell echo $(CONFIG_ARM_APPENDED_DTB_FILE)) +quiet_cmd_append = CAT $@ + cmd_append = (cat /dev/null $(dtbfile) >> $@) + +$(obj)/zImage: $(obj)/compressed/vmlinux $(dtbfile) FORCE $(call if_changed,objcopy) + $(call if_changed,append) @echo ' Kernel: $@ is ready' endif