On Mon, Nov 15, 2010 at 10:06 PM, Dirk Brandewie <dirk.brande...@gmail.com> wrote: > On 11/15/2010 08:41 PM, Grant Likely wrote: >> >> On Mon, Nov 15, 2010 at 08:01:20PM -0800, dirk.brande...@gmail.com wrote: >>> >>> From: Dirk Brandewie<dirk.brande...@gmail.com> >>> >>> This patch adds support for linking device tree blobs into >>> vmlinux. The device tree blobs are placed in the init.data >>> section. >>> >>> Signed-off-by: Dirk Brandewie<dirk.brande...@gmail.com> >>> --- >>> include/asm-generic/vmlinux.lds.h | 19 +++++++++++++++++-- >>> scripts/Makefile.lib | 17 +++++++++++++++++ >>> 2 files changed, 34 insertions(+), 2 deletions(-) >>> >>> diff --git a/include/asm-generic/vmlinux.lds.h >>> b/include/asm-generic/vmlinux.lds.h >>> index bd69d79..ea671e7 100644 >>> --- a/include/asm-generic/vmlinux.lds.h >>> +++ b/include/asm-generic/vmlinux.lds.h >>> @@ -67,7 +67,14 @@ >>> * 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) >>> + >>> +/* Device tree blobs linked into the kernel need to have proper >>> + * structure alignment to be parsed by the flat device tree library >>> + * used in early boot >>> +*/ >>> +#define DTB_ALIGNMENT STRUCT_ALIGNMENT >>> >>> /* The actual configuration determine if the init/exit sections >>> * are handled as text/data or they can be discarded (which >>> @@ -146,6 +153,13 @@ >>> #define TRACE_SYSCALLS() >>> #endif >>> >>> + >>> +#define KERNEL_DTB() \ >>> + . = ALIGN(DTB_ALIGNMENT); \ >>> + VMLINUX_SYMBOL(__dtb_start) = .; \ >>> + *(.dtb.init.rodata) \ >>> + VMLINUX_SYMBOL(__dtb_end) = .; >>> + >>> /* .data section */ >>> #define DATA_DATA \ >>> *(.data) \ >>> @@ -468,7 +482,8 @@ >>> 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) \ >>> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib >>> index 4c72c11..a8a4774 100644 >>> --- a/scripts/Makefile.lib >>> +++ b/scripts/Makefile.lib >>> @@ -200,6 +200,23 @@ quiet_cmd_gzip = GZIP $@ >>> cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -f -9> $@) || \ >>> (rm -f $@ ; false) >>> >>> +# DTC >>> +# >>> --------------------------------------------------------------------------- >>> +$(obj)/%.dtb.S: $(obj)/%.dtb FORCE >>> + @echo '#include<asm-generic/vmlinux.lds.h>'> $@ >>> + @echo '.section .dtb.init.rodata,"a"'>> $@ >>> + @echo '.balign DTB_ALIGNMENT'>> $@ >>> + @echo '.global __dtb_$(*F)_begin'>> $@ >>> + @echo '__dtb_$(*F)_begin:'>> $@ >>> + @echo '.incbin "$<" '>> $@ >>> + @echo '__dtb_$(*F)_end:'>> $@ >>> + @echo '.global __dtb_$(*F)_end'>> $@ >>> + @echo '.balign DTB_ALIGNMENT'>> $@ >>> + >>> +DTC = $(objtree)/scripts/dtc/dtc >>> + >>> +quiet_cmd_dtc = DTC $@ >>> + cmd_dtc = $(DTC) -O dtb -o $(obj)/$*.dtb -b 0 $(src)/$*.dts >> >> Missing the %.dtb: %.dts rule, but otherwise looks okay. You will >> need to make sure this doesn't break powerpc or microblaze when the >> dts->dtb rule is added. >> > I have the rule > $(obj)/%.dtb: $(src)/%.dts > $(call if_changed,dtc) > in the arch/x86/kernel/Makefile to prevent this sneaking into other other > architectures.
This rule looks correct. PowerPC and Microblaze need to be modified to use it. It should not be hard to do, give it a try. Worst case, your first attempt is wrong and the rest of us fix it up. :-) Hint: PowerPC currently puts the .dtb file in a different directory from the source .dts file. It doesn't need to do it that way. arch/powerpc/boot/Makefile will need to be modified. g. > > I need some more skilled in kbuild to help craft the more generic rule so we > can have the dts files anywhere in the arch/<*>/ directory structure and be > able to find the correct dts files. > > --Dirk > -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
