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

[Colin Watson]

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?

-- 
Colin Watson                                       address@hidden