diff options
| -rw-r--r-- | target/m68k/op_helper.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/target/m68k/op_helper.c b/target/m68k/op_helper.c index 730cdf7..5f981e5 100644 --- a/target/m68k/op_helper.c +++ b/target/m68k/op_helper.c @@ -468,7 +468,17 @@ void m68k_cpu_transaction_failed(CPUState *cs, hwaddr physaddr, vaddr addr, if (m68k_feature(env, M68K_FEATURE_M68040)) { env->mmu.mmusr = 0; - env->mmu.ssw |= M68K_ATC_040; + + /* + * According to the MC68040 users manual the ATC bit of the SSW is + * used to distinguish between ATC faults and physical bus errors. + * In the case of a bus error e.g. during nubus read from an empty + * slot this bit should not be set + */ + if (response != MEMTX_DECODE_ERROR) { + env->mmu.ssw |= M68K_ATC_040; + } + /* FIXME: manage MMU table access error */ env->mmu.ssw &= ~M68K_TM_040; if (env->sr & SR_S) { /* SUPERVISOR */ |