On PCXS chips (PA7000, pa 1.1a), trap #18 is raised on memory faults, while all later chips (>= PA7100) generate either trap #26, #27 or #28 (depending on the fault type).
Since the current qemu emulation emulates a B160L machine (with a PA7300LC PCX-L2 chip, we should raise trap #26 (EXCP_DMAR) instead of #18 (EXCP_DMP) on access faults by the Linux kernel to page zero. With the patch we now get the correct output (I tested against real hardware): Kernel Fault: Code=26 (Data memory access rights trap) (Addr=00000004) instead of: Kernel Fault: Code=18 (Data memory protection/unaligned access trap) (Addr=00000004) Signed-off-by: Helge Deller <del...@gmx.de> diff --git a/target/hppa/mem_helper.c b/target/hppa/mem_helper.c index ab160c2a74..aecf3075f6 100644 --- a/target/hppa/mem_helper.c +++ b/target/hppa/mem_helper.c @@ -137,7 +137,8 @@ int hppa_get_physical_address(CPUHPPAState *env, vaddr addr, int mmu_idx, if (unlikely(!(prot & type))) { /* The access isn't allowed -- Inst/Data Memory Protection Fault. */ - ret = (type & PAGE_EXEC ? EXCP_IMP : EXCP_DMP); + ret = (type & PAGE_EXEC ? EXCP_IMP : + prot & PAGE_READ ? EXCP_DMP : EXCP_DMAR); goto egress; }