haraldwolff/qemu-patch-raspberry4
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target-ppc: Fix SRR0 when taking unaligned exceptions

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We are setting SRR0 to the instruction before the one causing the
unaligned exception. A quick testcase:

. = 0x100
.globl _start
_start:
	/* Cause a 0x600 */
	li	3,0x1
	stwcx.	3,0,3
1:	b	1b

. = 0x600
1:	b	1b

Built into something we can load as a BIOS image:

gcc -mbig -c test.S
ld -EB -Ttext 0x0 -o test test.o
objcopy -O binary test test.bin

Run with:

qemu-system-ppc64 -nographic -bios test.bin

Shows an incorrect SRR0 (points at the li):

SRR0 0000000000000100

With the patch we get the correct SRR0:

SRR0 0000000000000104

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Anton Blanchard 2015-07-02 14:44:06 +10:00 committed by Alexander Graf
parent e7f08320f0
commit 6bb9a0a9ef
2 changed files with 2 additions and 2 deletions
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2
linux-user/main.c
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@ -1650,7 +1650,7 @@ void cpu_loop(CPUPPCState *env)
info.si_signo = TARGET_SIGBUS;
info.si_errno = 0;
info.si_code = TARGET_BUS_ADRALN;
info._sifields._sigfault._addr = env->nip - 4;
info._sifields._sigfault._addr = env->nip;
queue_signal(env, info.si_signo, &info);
break;
case POWERPC_EXCP_PROGRAM: /* Program exception */

2
target-ppc/excp_helper.c
View file

@ -200,7 +200,7 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
/* Get rS/rD and rA from faulting opcode */
env->spr[SPR_DSISR] |= (cpu_ldl_code(env, (env->nip - 4))
& 0x03FF0000) >> 16;
goto store_current;
goto store_next;
case POWERPC_EXCP_PROGRAM: /* Program exception */
switch (env->error_code & ~0xF) {
case POWERPC_EXCP_FP: