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| author | Dirk Brandewie <dirk.brandewie@gmail.com> | 2010-12-22 11:57:26 -0800 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2010-12-23 14:43:00 -0700 |
| commit | aab94339cd85d726abeae78fc02351fc1910e6a4 (patch) | |
| tree | 25d434a1dec4f758a9938e621dc1516f7a788521 /scripts | |
| parent | cfb13c5db08c90311a5defdde9a0328ee788cca5 (diff) | |
| download | lwn-aab94339cd85d726abeae78fc02351fc1910e6a4.tar.gz lwn-aab94339cd85d726abeae78fc02351fc1910e6a4.zip | |
of: Add support for linking device tree blobs into vmlinux
This patch adds support for linking device tree blob(s) into
vmlinux. Modifies asm-generic/vmlinux.lds.h to add linking
.dtb sections into vmlinux. To maintain compatiblity with the of/fdt
driver code platforms MUST copy the blob to a non-init memory location
before the kernel frees the .init.* sections in the image.
Modifies scripts/Makefile.lib to add a kbuild command to
compile DTS files to device tree blobs and a rule to create objects to
wrap the blobs for linking.
STRUCT_ALIGNMENT is defined in vmlinux.lds.h for use in the rule to
create wrapper objects for the dtb in Makefile.lib. The
STRUCT_ALIGN() macro in vmlinux.lds.h is modified to use the
STRUCT_ALIGNMENT definition.
The DTB's are placed on 32 byte boundries to allow parsing the blob
with driver/of/fdt.c during early boot without having to copy the blob
to get the structure alignment GCC expects.
A DTB is linked in by adding the DTB object to the list of objects to
be linked into vmlinux in the archtecture specific Makefile using
obj-y += foo.dtb.o
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: Michal Marek <mmarek@suse.cz>
[grant.likely@secretlab.ca: cleaned up whitespace inconsistencies]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/Makefile.lib | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 4c72c1189479..396da16aabf8 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -200,6 +200,29 @@ quiet_cmd_gzip = GZIP $@ cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -f -9 > $@) || \ (rm -f $@ ; false) +# DTC +# --------------------------------------------------------------------------- + +# Generate an assembly file to wrap the output of the device tree compiler +quiet_cmd_dt_S_dtb= DTB $@ +cmd_dt_S_dtb= \ +( \ + echo '\#include <asm-generic/vmlinux.lds.h>'; \ + echo '.section .dtb.init.rodata,"a"'; \ + echo '.balign STRUCT_ALIGNMENT'; \ + echo '.global __dtb_$(*F)_begin'; \ + echo '__dtb_$(*F)_begin:'; \ + echo '.incbin "$<" '; \ + echo '__dtb_$(*F)_end:'; \ + echo '.global __dtb_$(*F)_end'; \ + echo '.balign STRUCT_ALIGNMENT'; \ +) > $@ + +$(obj)/%.dtb.S: $(obj)/%.dtb + $(call cmd,dt_S_dtb) + +quiet_cmd_dtc = DTC $@ +cmd_dtc = $(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) $< # Bzip2 # --------------------------------------------------------------------------- |