Re: [Qemu-devel] Problem with translating on ARM and Qemu beginner question

[Peter Maydell]

On 25 November 2011 15:35, Max Filippov <address@hidden> wrote:
>> Breakpoint 7, cpu_arm_exec (env=0x102033200) at ~/qemu-0.15.0/cpu-exec.c:557
>> 557                         next_tb = tcg_qemu_tb_exec(env, tc_ptr);
>> (gdb) p/x env->regs
>> $13 = {0x4002c00c, 0x20, 0x4, 0x0, 0x0, 0x0, 0x40000, 0x0, 0x0, 0x0, 0x0, 
>> 0x0, 0x30, 0x10007fa8, 0x560d, 0x560c}
>> (gdb) s
>> 558                         if ((next_tb & 3) == 2) {
>> (gdb) p/x env->regs
>> $14 = {0x10048000, 0x20, 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
>> 0x30, 0x10007fb8, 0x560d, 0x0}
>>
>> How to check access to unallocated memory? It's not seg faulting.
>
> 290 0000042c <_init>:
> 291  42c:   b5f8        push    {r3, r4, r5, r6, r7, lr}
>
> set breakpoint here and see with x/6wx $sp whether saved register values are 
> good.

To clarify this a bit: that means "set a breakpoint in an ARM gdb attached
to qemu's gdb-stub interface". That gdb will see the view of the guest
CPU, whereas connecting an x86 gdb directly to qemu you're looking at
qemu's internal data structures, which can be more confusing.

-- PMM