Messages in this thread | | | Date | Tue, 16 Nov 2010 18:21:08 -0800 | From | Dirk Brandewie <> | Subject | Re: [PATCH 1/5] of: Add support for linking device tree blobs into vmlinux |
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On 11/16/2010 04:39 PM, David Daney wrote: > Thanks for doing this. However I have a few comments... > > On 11/16/2010 02:41 PM, dirk.brandewie@gmail.com wrote: >> From: Dirk Brandewie<dirk.brandewie@gmail.com> >> >> /* .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() >> > > I thought the init.rodata was only for data used by __init things. Although the > current linker scripts do not put it in the section that gets recycled as usable > memory. > > IIRC the unflattened version of the device tree has pointers to the flattened > data. Since the device tree nodes are live for the entire kernel lifecycle, > shouldn't the device tree blobs be in non-init memory? >
The contents of the blob get copied to allocated memory during unflatten_device_tree() so the blob that is linked in is no longer needed after init.
> >> #define INIT_TEXT \ >> *(.init.text) \ >> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib >> index 4c72c11..29db062 100644 >> --- a/scripts/Makefile.lib >> +++ b/scripts/Makefile.lib >> @@ -200,6 +200,26 @@ quiet_cmd_gzip = GZIP $@ >> cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -f -9> $@) || \ >> (rm -f $@ ; false) >> >> +# DTC >> +# --------------------------------------------------------------------------- >> +$(obj)/%.dtb.S: $(obj)/%.dtb FORCE > > Why FORCE? Crud left over from debugging I will remove. > > >> + @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 $(DTS_FLAGS) $(src)/dts/$*.dts >> + >> +$(obj)/%.dtb: $(src)/dts/%.dts >> + $(call if_changed,dtc) >> > > Do all the generated files get cleaned up? > > I will try it tomorrow to see for sure. > Looks like I need to add the generated .S files to clean-files
> > Thanks, > David Daney
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