diff options
| -rw-r--r-- | hw/mips/mips_jazz.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/hw/mips/mips_jazz.c b/hw/mips/mips_jazz.c index 49bdd02..5f6dd9f 100644 --- a/hw/mips/mips_jazz.c +++ b/hw/mips/mips_jazz.c @@ -108,6 +108,18 @@ static void cpu_request_exit(void *opaque, int irq, int level) } } +static CPUUnassignedAccess real_do_unassigned_access; +static void mips_jazz_do_unassigned_access(CPUState *cpu, hwaddr addr, + bool is_write, bool is_exec, + int opaque, unsigned size) +{ + if (!is_exec) { + /* ignore invalid access (ie do not raise exception) */ + return; + } + (*real_do_unassigned_access)(cpu, addr, is_write, is_exec, opaque, size); +} + static void mips_jazz_init(MemoryRegion *address_space, MemoryRegion *address_space_io, ram_addr_t ram_size, @@ -117,6 +129,7 @@ static void mips_jazz_init(MemoryRegion *address_space, char *filename; int bios_size, n; MIPSCPU *cpu; + CPUClass *cc; CPUMIPSState *env; qemu_irq *rc4030, *i8259; rc4030_dma *dmas; @@ -154,6 +167,17 @@ static void mips_jazz_init(MemoryRegion *address_space, env = &cpu->env; qemu_register_reset(main_cpu_reset, cpu); + /* Chipset returns 0 in invalid reads and do not raise data exceptions. + * However, we can't simply add a global memory region to catch + * everything, as memory core directly call unassigned_mem_read/write + * on some invalid accesses, which call do_unassigned_access on the + * CPU, which raise an exception. + * Handle that case by hijacking the do_unassigned_access method on + * the CPU, and do not raise exceptions for data access. */ + cc = CPU_GET_CLASS(cpu); + real_do_unassigned_access = cc->do_unassigned_access; + cc->do_unassigned_access = mips_jazz_do_unassigned_access; + /* allocate RAM */ memory_region_init_ram(ram, NULL, "mips_jazz.ram", ram_size); vmstate_register_ram_global(ram); |