From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH 2/4] of: Add support for linking device tree blobs into vmlinux Date: Sat, 13 Nov 2010 22:25:25 -0700 Message-ID: <20101114052525.GC2355@angua.secretlab.ca> References: <7d0a9d70f1616340115c187547006c76b0135ca7.1289520079.git.dirk.brandewie@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <7d0a9d70f1616340115c187547006c76b0135ca7.1289520079.git.dirk.brandewie-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: dirk.brandewie-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Cc: sodaville-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, arjan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org List-Id: devicetree@vger.kernel.org On Thu, Nov 11, 2010 at 04:03:48PM -0800, dirk.brandewie-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote: > From: Dirk Brandewie > > 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 > --- > include/asm-generic/vmlinux.lds.h | 13 ++++++++++++- > init/Kconfig | 7 +++++++ > scripts/Makefile.lib | 14 ++++++++++++++ > 3 files changed, 33 insertions(+), 1 deletions(-) > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > index bd69d79..c8f600e 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -146,6 +146,16 @@ > #define TRACE_SYSCALLS() > #endif > > +#ifdef CONFIG_KERNEL_DTB > +#define KERNEL_DTB \ To match other definitions in this file, this should be defined with parentheses: #define KERNEL_DTB() > + . = ALIGN(32); \ > + VMLINUX_SYMBOL(__dtb_start) = .; \ > + *(.dtb) \ I wonder if .meminit.rodata.dtb be a better section name. Could use some input from more experienced kernel hackers here. hpa, what say you? Also, inconsistent indentation (mixed tabs and spaces). > + VMLINUX_SYMBOL(__dtb_end) = .; > +#else > +#define KERNEL_DTB > +#endif > + Does this need to be wrapped with CONFIG_KERNEL_DTB? Is there any downside to including these sections unconditionally? > /* .data section */ > #define DATA_DATA \ > *(.data) \ > @@ -468,7 +478,8 @@ > 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/init/Kconfig b/init/Kconfig > index 88c1046..fddfc0f 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1083,6 +1083,13 @@ config PCI_QUIRKS > bugs/quirks. Disable this only if your target machine is > unaffected by PCI quirks. > > +config KERNEL_DTB > + bool "Support linking a device tree blob into vmlinux" > + default n > + help > + This option provides support for adding a device tree blob(s) > + directly to vmlinux Inconsistent indentation. I'm also not convinced that this Kconfig symbol is really needed (as commented on above). > + > config SLUB_DEBUG > default y > bool "Enable SLUB debugging support" if EMBEDDED > diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib > index 4c72c11..c4487b2 100644 > --- a/scripts/Makefile.lib > +++ b/scripts/Makefile.lib > @@ -200,6 +200,20 @@ quiet_cmd_gzip = GZIP $@ > cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -f -9 > $@) || \ > (rm -f $@ ; false) > > +# DTC > +# --------------------------------------------------------------------------- > +$(obj)/%.dtb.S: $(obj)/%.dtb FORCE > + @echo '.section .dtb,"a"' > $@ > + @echo '.global __dtb_$(*F)_begin' >> $@ > + @echo '__dtb_$(*F)_begin:' >> $@ > + @echo '.incbin "$<" ' >> $@ > + @echo '__dtb_$(*F)_end:' >> $@ > + @echo '.global __dtb_$(*F)_end' >> $@ > + > +DTC = $(objtree)/scripts/dtc/dtc > + > +quiet_cmd_dtc = DTC $@ > + cmd_dtc = $(DTC) -O dtb -o $(obj)/$*.dtb -b 0 $(dtstree)/$*.dts As already mentioned; need to rationalized these rule additions with the changes made in patch #1. g.