Atsushi Nemoto wrote:
I'm trying to compile kernel with gcc 3.3.1 and binutils 2.14. I
found this report on this ML:
On Tue, 13 May 2003 13:33:16 +0200, Guido Guenther <firstname.lastname@example.org> said:
Guido> Just for completeness: I had to use:
Guido> GCCFLAGS += -mabi=32 -march=r4600 -mtune=r4600 -Wa,--trap
Guido> to make gcc-3.3 happy (note the 32 instead of o32). gcc-3.2
Guido> doesn't seem to handle these options correctly at all.
It can compile the kernel, but handle_adel_int (and handle_ades_int)
contain wrong codes.
8002630c <handle_adel_int> 40284000 dmfc0 t0,$8
80026310 <handle_adel_int+0x4> 00000000 nop
80026314 <handle_adel_int+0x8> ffa800a4 sd t0,164(sp)
The source code for this instructions are:
#define __BUILD_clear_ade(exception) \
.set reorder; \
MFC0 t0,CP0_BADVADDR; \
.set noreorder; \
REG_S t0,PT_BVADDR(sp); \
The macro MFC0 and REG_S are defined asm.h and depend on _MIPS_ISA.
#if (_MIPS_ISA == _MIPS_ISA_MIPS1) || (_MIPS_ISA == _MIPS_ISA_MIPS2) || \
(_MIPS_ISA == _MIPS_ISA_MIPS32)
#define MFC0 mfc0
#define MTC0 mtc0
#if (_MIPS_ISA == _MIPS_ISA_MIPS3) || (_MIPS_ISA == _MIPS_ISA_MIPS4) || \
(_MIPS_ISA == _MIPS_ISA_MIPS5) || (_MIPS_ISA == _MIPS_ISA_MIPS64)
#define MFC0 dmfc0
#define MTC0 dmtc0
The option -march=r4600 seems to make gcc 3.3.x choose MIPS_ISA_MIPS3.
So, the right options is:
GCCFLAGS += -mabi=32 -march=mips2 -mtune=r4600 -Wa,--trap
(or GCCFLAGS += $(call check_gcc, -mcpu=r4600 -mips2, -mabi=32 -march=mips2
I don't claim to be an expert on all things mips yet, but If I recall
correctly, the R4K processor line is a MIPS III capable processor. So
-mips3 -mabi=32 should be safe for it. I've been building kernels off
linux-mips.org CVS using "-mips3 -mabi=32 -Wa,--trap" in the
arch/mips/Makefile, and it works great.
Several people I know using Indy's with R5000 processors use "-mips4
-mabi=32 -Wa,--trap" (cause R5K is MIPS IV). I know with gcc-3.3.x,
-mipsX is just a synonym for the appropriate -march specifier, so it
doesn't seem to make a different whether one uses -march or -mipsX.
I'm slowly working on building a Gentoo install using "-mips3 -mabi=32"
code on my Indigo2 (Right now, it's a mix of -mips2 and -mips3 with a
random -mips1 binary scattered around). Quite a fun, albeit slow,
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