The move to the new configure/automake uses $(CCASCOMPILE) for compiling
.S files into .o files. This ends up being the same gcc compiler used
for C files. However, CCASCOMPILE uses its own set of flags: e.g.
CCASFLAGS instead of CFLAGS.
Now, config-ml.in which adds the multilib logic gets special multilib
flags from the compiler and appends them to a set of flags to be passed
when building a particular multilib. It adds these flags to CFLAGS, but
neglects to add them to CCASFLAGS.
I propose the attached patch to fix this. Shaun, please try it out.
DJ, I cc'd you as you are listed in the MAINTAINERS file for
config-ml.in. Ok?
-- Jeff J.
Shaun Jackman wrote:
> The functions setjmp and longmp in the thumb libc.a are in fact
> compiled as ARM code.
>
> The linker complains when I attempt to link my program.
>
> /usr/local/lib/gcc/arm-elf/4.1.0/../../../../arm-elf/bin/ld:
> /usr/local/lib/gcc/arm-elf/4.1.0/../../../../arm-elf/lib/thumb/libg.a(lib_a-setjmp.o)(longjmp):
>
> warning: interworking not enabled.
> first occurrence: proc.o: thumb call to arm
> proc.o: In function `kexit':../../kernel/proc.c:55: warning: internal
> error: dangerous error
>
> $ arm-elf-objdump -rS
> ./arm-elf/thumb/newlib/libc/machine/arm/lib_a-setjmp.o
>
> ./arm-elf/thumb/newlib/libc/machine/arm/lib_a-setjmp.o: file
> format elf32-littlearm
>
> Disassembly of section .text:
>
> 00000000 <setjmp>:
> 0: e8a07ff0 stmia r0!, {r4, r5, r6, r7, r8, r9, sl, fp,
> ip, sp, lr}
> 4: e3a00000 mov r0, #0 ; 0x0
> 8: e31e0001 tst lr, #1 ; 0x1
> c: 01a0f00e moveq pc, lr
> 10: e12fff1e bx lr
>
> 00000014 <longjmp>:
> 14: e8b07ff0 ldmia r0!, {r4, r5, r6, r7, r8, r9, sl, fp,
> ip, sp, lr}
> 18: e1b00001 movs r0, r1
> 1c: 03a00001 moveq r0, #1 ; 0x1
> 20: e31e0001 tst lr, #1 ; 0x1
> 24: 01a0f00e moveq pc, lr
> 28: e12fff1e bx lr
>
> Here are the relevant lines from the compilation:
>
> make[9]: Entering directory
> `/home/sjackman/src/toolchain/src/_build/arm-elf/thumb/newlib/libc/machine/arm'
>
> arm-elf-gcc -B/home/sjackman/src/toolchain/src/_build/arm-elf/newlib/
> -isystem
> /home/sjackman/src/toolchain/src/_build/arm-elf/newlib/targ-include
> -isystem /home/sjackman/src/toolchain/src/newlib/libc/include -O2
> -D__NO_SYSCALLS__ -DNO_FLOATING_POINT -DHAVE_FCNTL -DHAVE_GETTIMEOFDAY
> -DHAVE_NANOSLEEP -fno-builtin -c -o lib_a-setjmp.o `test -f
> 'setjmp.S' || echo
> '../../../../../../../newlib/libc/machine/arm/'`setjmp.S
> rm -f lib.a
> arm-elf-ar cru lib.a lib_a-setjmp.o lib_a-access.o
> arm-elf-ranlib lib.a
> make[9]: Leaving directory
> `/home/sjackman/src/toolchain/src/_build/arm-elf/thumb/newlib/libc/machine/arm'
>
>
> It looks as though the option -mthumb has been omitted.
>
> Cheers,
> Shaun