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| author | Dirk Brandewie <dirk.brandewie@gmail.com> | 2010-12-22 20:57:26 +0100 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2010-12-23 22:43:00 +0100 |
| commit | aab94339cd85d726abeae78fc02351fc1910e6a4 (patch) | |
| tree | 25d434a1dec4f758a9938e621dc1516f7a788521 /include/asm-generic | |
| parent | Merge commit 'v2.6.37-rc7' into devicetree/next (diff) | |
| download | linux-aab94339cd85d726abeae78fc02351fc1910e6a4.tar.xz linux-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 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index bd69d79208de..05cbad03c5ab 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -67,7 +67,8 @@ * Align to a 32 byte boundary equal to the * alignment gcc 4.5 uses for a struct */ -#define STRUCT_ALIGN() . = ALIGN(32) +#define STRUCT_ALIGNMENT 32 +#define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT) /* The actual configuration determine if the init/exit sections * are handled as text/data or they can be discarded (which @@ -146,6 +147,13 @@ #define TRACE_SYSCALLS() #endif + +#define KERNEL_DTB() \ + STRUCT_ALIGN(); \ + VMLINUX_SYMBOL(__dtb_start) = .; \ + *(.dtb.init.rodata) \ + VMLINUX_SYMBOL(__dtb_end) = .; + /* .data section */ #define DATA_DATA \ *(.data) \ @@ -468,7 +476,8 @@ MCOUNT_REC() \ DEV_DISCARD(init.rodata) \ CPU_DISCARD(init.rodata) \ - MEM_DISCARD(init.rodata) + MEM_DISCARD(init.rodata) \ + KERNEL_DTB() #define INIT_TEXT \ *(.init.text) \ |