| Message ID | 1397147232-28516-1-git-send-email-taras.kondratiuk@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 10 Apr 2014, Taras Kondratiuk wrote: > From: Nico Pitre <nico@fluxnic.net> Please use "Nicolas Pitre" as my full name. > All known BE8-capable systems have LE bootloaders, so we need to ensure > that the magic number and image start/end values are in little endian > format. > > [ben.dooks@codethink.co.uk: from nico's original email on this subject] > Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> > [taras.kondratiuk@linaro.org: removed lds.S->lds rule, added target to extra-y] > Signed-off-by: Taras Kondratiuk <taras.kondratiuk@linaro.org> > --- > Nico, should I add your Signed-off-by? Sure. > > Discussion about the patch: > http://www.spinics.net/lists/arm-kernel/msg320670.html > > Based on v3.14+ master commit 39de65aa2c3eee901db020a4f1396998e09602a3 > > arch/arm/boot/compressed/.gitignore | 1 + > arch/arm/boot/compressed/Makefile | 4 ++-- > arch/arm/boot/compressed/head.S | 7 ++++--- > arch/arm/boot/compressed/vmlinux.lds.in | 14 ++++++++++++++ > 4 files changed, 21 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/boot/compressed/.gitignore b/arch/arm/boot/compressed/.gitignore > index 0714e03..6a26e7b 100644 > --- a/arch/arm/boot/compressed/.gitignore > +++ b/arch/arm/boot/compressed/.gitignore > @@ -10,6 +10,7 @@ piggy.xzkern > piggy.lz4 > vmlinux > vmlinux.lds > +vmlinux.lds.S > > # borrowed libfdt files > fdt.c > diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile > index 68c9183..8a80906 100644 > --- a/arch/arm/boot/compressed/Makefile > +++ b/arch/arm/boot/compressed/Makefile > @@ -114,7 +114,7 @@ targets := vmlinux vmlinux.lds \ > # Make sure files are removed during clean > extra-y += piggy.gzip piggy.lzo piggy.lzma piggy.xzkern piggy.lz4 \ > lib1funcs.S ashldi3.S bswapsdi2.S $(libfdt) $(libfdt_hdrs) \ > - hyp-stub.S > + hyp-stub.S vmlinux.lds.S > > ifeq ($(CONFIG_FUNCTION_TRACER),y) > ORIG_CFLAGS := $(KBUILD_CFLAGS) > @@ -199,7 +199,7 @@ CFLAGS_font.o := -Dstatic= > $(obj)/font.c: $(FONTC) > $(call cmd,shipped) > > -$(obj)/vmlinux.lds: $(obj)/vmlinux.lds.in arch/arm/boot/Makefile $(KCONFIG_CONFIG) > +$(obj)/vmlinux.lds.S: $(obj)/vmlinux.lds.in arch/arm/boot/Makefile $(KCONFIG_CONFIG) > @sed "$(SEDFLAGS)" < $< > $@ > > $(obj)/hyp-stub.S: $(srctree)/arch/$(SRCARCH)/kernel/hyp-stub.S > diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S > index 066b034..8ea1773 100644 > --- a/arch/arm/boot/compressed/head.S > +++ b/arch/arm/boot/compressed/head.S > @@ -130,9 +130,10 @@ start: > THUMB( adr r12, BSYM(1f) ) > THUMB( bx r12 ) > > - .word 0x016f2818 @ Magic numbers to help the loader > - .word start @ absolute load/run zImage address > - .word _edata @ zImage end address > + .word _magic_sig @ Magic numbers to help the loader > + .word _magic_start @ absolute load/run zImage address > + .word _magic_end @ zImage end address > + > THUMB( .thumb ) > 1: > ARM_BE8( setend be ) @ go BE8 if compiled for BE8 > diff --git a/arch/arm/boot/compressed/vmlinux.lds.in b/arch/arm/boot/compressed/vmlinux.lds.in > index 4919f2a..6016223 100644 > --- a/arch/arm/boot/compressed/vmlinux.lds.in > +++ b/arch/arm/boot/compressed/vmlinux.lds.in > @@ -7,6 +7,16 @@ > * it under the terms of the GNU General Public License version 2 as > * published by the Free Software Foundation. > */ > + > +#ifdef CONFIG_CPU_ENDIAN_BE8 > +#define ZIMAGE_MAGIC(x) ( (((x) >> 24) & 0x000000ff) | \ > + (((x) >> 8) & 0x0000ff00) | \ > + (((x) << 8) & 0x00ff0000) | \ > + (((x) << 24) & 0xff000000) ) > +#else > +#define ZIMAGE_MAGIC(x) (x) > +#endif > + > OUTPUT_ARCH(arm) > ENTRY(_start) > SECTIONS > @@ -57,6 +67,10 @@ SECTIONS > .pad : { BYTE(0); . = ALIGN(8); } > _edata = .; > > + _magic_sig = ZIMAGE_MAGIC(0x016f2818); > + _magic_start = ZIMAGE_MAGIC(_start); > + _magic_end = ZIMAGE_MAGIC(_edata); > + > . = BSS_START; > __bss_start = .; > .bss : { *(.bss) } > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
On Thu, Apr 10, 2014 at 9:27 AM, Taras Kondratiuk <taras.kondratiuk@linaro.org> wrote: > From: Nico Pitre <nico@fluxnic.net> > > All known BE8-capable systems have LE bootloaders, so we need to ensure > that the magic number and image start/end values are in little endian > format. > > [ben.dooks@codethink.co.uk: from nico's original email on this subject] > Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> > [taras.kondratiuk@linaro.org: removed lds.S->lds rule, added target to extra-y] > Signed-off-by: Taras Kondratiuk <taras.kondratiuk@linaro.org> This patch has now hit -next (as of next-20140618) and I noticed all my big-endian boot tests failed[1]. Turns out they failed because I'm deciding whether to pass a big-endian or little-endian initramfs based on the magic number of the zImage. Since it's now always little endian, even the big-endian kernels were boot tested with a little endian initramfs. And guess what.... they failed. I like this patch for several reasons, including the fact that u-boot's bootz support checks the magic number and failed before this patch. All of that to say, with this patch applied, I need a new (and reliable) way to determine the endianness of a kernel just by looking at the zImage. Recommendations welcome. Thanks, Kevin [1] http://lists.linaro.org/pipermail/kernel-build-reports/2014-June/004059.html
On 06/18/14 10:55, Kevin Hilman wrote: > > All of that to say, with this patch applied, I need a new (and > reliable) way to determine the endianness of a kernel just by looking > at the zImage. Recommendations welcome. Assuming that you have the .config configured to be built into the kernel you could use extract-ikconfig $ ./scripts/extract-ikconfig zImage | grep CONFIG_CPU_ENDIAN_BE8
On Wed, Jun 18, 2014 at 11:14 AM, Stephen Boyd <sboyd@codeaurora.org> wrote: > On 06/18/14 10:55, Kevin Hilman wrote: >> >> All of that to say, with this patch applied, I need a new (and >> reliable) way to determine the endianness of a kernel just by looking >> at the zImage. Recommendations welcome. > > Assuming that you have the .config configured to be built into the > kernel you could use extract-ikconfig > > $ ./scripts/extract-ikconfig zImage | grep CONFIG_CPU_ENDIAN_BE8 Unfortunately, I can't rely on having that built in since I want the boot tools to be as generic as possible. Kevin
On 06/18/14 11:21, Kevin Hilman wrote: > On Wed, Jun 18, 2014 at 11:14 AM, Stephen Boyd <sboyd@codeaurora.org> wrote: >> On 06/18/14 10:55, Kevin Hilman wrote: >>> All of that to say, with this patch applied, I need a new (and >>> reliable) way to determine the endianness of a kernel just by looking >>> at the zImage. Recommendations welcome. >> Assuming that you have the .config configured to be built into the >> kernel you could use extract-ikconfig >> >> $ ./scripts/extract-ikconfig zImage | grep CONFIG_CPU_ENDIAN_BE8 > Unfortunately, I can't rely on having that built in since I want the > boot tools to be as generic as possible. > > Yeah ok. Perhaps you can look for the 'setend be' instruction right after the magic values instead.
On Wed, Jun 18, 2014 at 11:22 AM, Stephen Boyd <sboyd@codeaurora.org> wrote: > On 06/18/14 11:21, Kevin Hilman wrote: >> On Wed, Jun 18, 2014 at 11:14 AM, Stephen Boyd <sboyd@codeaurora.org> wrote: >>> On 06/18/14 10:55, Kevin Hilman wrote: >>>> All of that to say, with this patch applied, I need a new (and >>>> reliable) way to determine the endianness of a kernel just by looking >>>> at the zImage. Recommendations welcome. >>> Assuming that you have the .config configured to be built into the >>> kernel you could use extract-ikconfig >>> >>> $ ./scripts/extract-ikconfig zImage | grep CONFIG_CPU_ENDIAN_BE8 >> Unfortunately, I can't rely on having that built in since I want the >> boot tools to be as generic as possible. >> >> > > Yeah ok. Perhaps you can look for the 'setend be' instruction right > after the magic values instead. Yeah, that works, as long as I can always assume that instruction will be at the same offset (currently at 0x30). Kevin
diff --git a/arch/arm/boot/compressed/.gitignore b/arch/arm/boot/compressed/.gitignore index 0714e03..6a26e7b 100644 --- a/arch/arm/boot/compressed/.gitignore +++ b/arch/arm/boot/compressed/.gitignore @@ -10,6 +10,7 @@ piggy.xzkern piggy.lz4 vmlinux vmlinux.lds +vmlinux.lds.S # borrowed libfdt files fdt.c diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 68c9183..8a80906 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -114,7 +114,7 @@ targets := vmlinux vmlinux.lds \ # Make sure files are removed during clean extra-y += piggy.gzip piggy.lzo piggy.lzma piggy.xzkern piggy.lz4 \ lib1funcs.S ashldi3.S bswapsdi2.S $(libfdt) $(libfdt_hdrs) \ - hyp-stub.S + hyp-stub.S vmlinux.lds.S ifeq ($(CONFIG_FUNCTION_TRACER),y) ORIG_CFLAGS := $(KBUILD_CFLAGS) @@ -199,7 +199,7 @@ CFLAGS_font.o := -Dstatic= $(obj)/font.c: $(FONTC) $(call cmd,shipped) -$(obj)/vmlinux.lds: $(obj)/vmlinux.lds.in arch/arm/boot/Makefile $(KCONFIG_CONFIG) +$(obj)/vmlinux.lds.S: $(obj)/vmlinux.lds.in arch/arm/boot/Makefile $(KCONFIG_CONFIG) @sed "$(SEDFLAGS)" < $< > $@ $(obj)/hyp-stub.S: $(srctree)/arch/$(SRCARCH)/kernel/hyp-stub.S diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 066b034..8ea1773 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -130,9 +130,10 @@ start: THUMB( adr r12, BSYM(1f) ) THUMB( bx r12 ) - .word 0x016f2818 @ Magic numbers to help the loader - .word start @ absolute load/run zImage address - .word _edata @ zImage end address + .word _magic_sig @ Magic numbers to help the loader + .word _magic_start @ absolute load/run zImage address + .word _magic_end @ zImage end address + THUMB( .thumb ) 1: ARM_BE8( setend be ) @ go BE8 if compiled for BE8 diff --git a/arch/arm/boot/compressed/vmlinux.lds.in b/arch/arm/boot/compressed/vmlinux.lds.in index 4919f2a..6016223 100644 --- a/arch/arm/boot/compressed/vmlinux.lds.in +++ b/arch/arm/boot/compressed/vmlinux.lds.in @@ -7,6 +7,16 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ + +#ifdef CONFIG_CPU_ENDIAN_BE8 +#define ZIMAGE_MAGIC(x) ( (((x) >> 24) & 0x000000ff) | \ + (((x) >> 8) & 0x0000ff00) | \ + (((x) << 8) & 0x00ff0000) | \ + (((x) << 24) & 0xff000000) ) +#else +#define ZIMAGE_MAGIC(x) (x) +#endif + OUTPUT_ARCH(arm) ENTRY(_start) SECTIONS @@ -57,6 +67,10 @@ SECTIONS .pad : { BYTE(0); . = ALIGN(8); } _edata = .; + _magic_sig = ZIMAGE_MAGIC(0x016f2818); + _magic_start = ZIMAGE_MAGIC(_start); + _magic_end = ZIMAGE_MAGIC(_edata); + . = BSS_START; __bss_start = .; .bss : { *(.bss) }