| Message ID | alpine.LFD.2.03.1302121707250.1242@fluxnic.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12/02/13 22:13, Nicolas Pitre wrote: > On Tue, 12 Feb 2013, Ben Dooks wrote: > >> If we ignore the ATAG issue, then most of the support is currently in >> the kernel to do this and there's not a lot of changes. > > You could make CPU_BE8_BOOT_LE depend on !ATAG. That would be one consideration. For my next series I've removed the CPU_BE8_BOOT_LE and added the 'setend be' as conditional on running BE8 as this is such as small code addition it seems to make sense to do it that way. I will put together a new series that deals with the endian-ness of the bootloader. >> I think that some of the boot changes could be dealt with by a >> post-process of the zImage (such as the zImage magic) which would make >> this series less intrusive to the kernel. > > No, please don't do that. Especially if the kernel binary _expects_ to > be booted from a LE environment. Otherwise we might end up with > kernels that don't boot because there are environment expectation > mismatch, etc. > > Here's what could be done for the zImage header: I will keep this in mind, it looks like a pretty good solution to the whole issue. > diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S > index 4d5f4192ee..2077ebb734 100644 > --- a/arch/arm/boot/compressed/head.S > +++ b/arch/arm/boot/compressed/head.S > @@ -129,9 +129,9 @@ 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 @ Signature to help the loader (0x016f2818) > + .word _magic_start @ zImage load/run address (0 if relocatable) > + .word _magic_end @ zImage end address > THUMB( .thumb ) > 1: > mrs r9, cpsr > diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile > index a517153a13..52539f46c1 100644 > --- a/arch/arm/boot/compressed/Makefile > +++ b/arch/arm/boot/compressed/Makefile > @@ -200,8 +200,11 @@ 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)/vmlinux.lds: $(obj)/vmlinux.lds.S > + $(call if_changed,cpp_lds_S) > + > $(obj)/hyp-stub.S: $(srctree)/arch/$(SRCARCH)/kernel/hyp-stub.S > $(call cmd,shipped) > diff --git a/arch/arm/boot/compressed/vmlinux.lds.in b/arch/arm/boot/compressed/vmlinux.lds.in > index 4919f2ac8b..567250fb7d 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_BE8_BOOT_LE > +#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) }
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 4d5f4192ee..2077ebb734 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -129,9 +129,9 @@ 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 @ Signature to help the loader (0x016f2818) + .word _magic_start @ zImage load/run address (0 if relocatable) + .word _magic_end @ zImage end address THUMB( .thumb ) 1: mrs r9, cpsr diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index a517153a13..52539f46c1 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -200,8 +200,11 @@ 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)/vmlinux.lds: $(obj)/vmlinux.lds.S + $(call if_changed,cpp_lds_S) + $(obj)/hyp-stub.S: $(srctree)/arch/$(SRCARCH)/kernel/hyp-stub.S $(call cmd,shipped) diff --git a/arch/arm/boot/compressed/vmlinux.lds.in b/arch/arm/boot/compressed/vmlinux.lds.in index 4919f2ac8b..567250fb7d 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_BE8_BOOT_LE +#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) }