Re: arm-uboot: misc.S:56: Error: r13 not allowed here -- `sub sp,fp,#4'

[Leif Lindholm]

On Wed, Nov 13, 2013 at 02:49:19PM +0000, Colin Watson wrote:
> After my previous fix, arm-uboot still fails to build with:
> 
>   arm-linux-gnueabihf-gcc -DHAVE_CONFIG_H -I. -I../../../grub-core -I..  
> -Wall -W -I../../../include -I../include  -DGRUB_MACHINE_UBOOT=1 
> -DGRUB_MACHINE_ARM=1 -DGRUB_MACHINE=ARM_UBOOT -DGRUB_TARGET_CPU_ARM=1 
> -nostdinc -isystem /usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/include 
> -DGRUB_FILE=\"lib/arg.c\" -I. -I../../../grub-core -I.. -I../../.. 
> -I../../../include -I../include 
> -I../../../grub-core/lib/libgcrypt-grub/include 
> -I../../../grub-core/lib/libgcrypt-grub/src/   -DGRUB_KERNEL=1   -Os -Wall -W 
> -Wshadow -Wold-style-definition -Wpointer-arith -Wundef -Wextra -Wattributes 
> -Wchar-subscripts -Wcomment -Wdeprecated-declarations -Wdisabled-optimization 
> -Wdiv-by-zero -Wendif-labels -Wfloat-equal -Wformat-extra-args 
> -Wformat-security -Wformat-y2k -Wimplicit -Wimplicit-function-declaration 
> -Wimplicit-int -Winit-self -Wint-to-pointer-cast -Winvalid-pch -Wmain 
> -Wmissing-braces -Wmissing-field-initializers -Wmissing-format-attribute 
> -Wmultichar -Wnonnull -Woverflow -Wparentheses -Wpointer-arith 
> -Wpointer-to-int-cast -Wreturn-type -Wsequence-point -Wshadow -Wsign-compare 
> -Wstrict-aliasing -Wswitch -Wtrigraphs -Wundef -Wunknown-pragmas -Wunused 
> -Wunused-function -Wunused-label -Wunused-parameter -Wunused-value  
> -Wunused-variable -Wvariadic-macros -Wvolatile-register-var -Wwrite-strings 
> -Wnested-externs -Wstrict-prototypes -Wpointer-sign -g -Wredundant-decls 
> -Wmissing-prototypes -Wmissing-declarations -Wcast-align -freg-struct-return 
> -fno-dwarf2-cfi-asm -fno-asynchronous-unwind-tables -fno-stack-protector 
> -mno-unaligned-access -Wtrampolines -Werror -DUSE_ASCII_FALLBACK=1 
> -DHAVE_UNIFONT_WIDTHSPEC=1     -mthumb-interwork -mlong-calls -ffreestanding  
>  -MT lib/kernel_exec-arg.o -MD -MP -MF lib/.deps-core/kernel_exec-arg.Tpo -c 
> -o lib/kernel_exec-arg.o `test -f 'lib/arg.c' || echo 
> '../../../grub-core/'`lib/arg.c
>   misc.S: Assembler messages:
>   misc.S:56: Error: r13 not allowed here -- `sub sp,fp,#4'
>   make[3]: *** [kern/arm/kernel_exec-misc.o] Error 1
> 
> I don't think SP can be used that way in Thumb mode?

No, you would need to insert a
    mov sp, fp
and then change to
    sub sp, sp, #4

/
    Leif