From: Max Filippov <jcmvbkbc@gmail.com>
To: Gauresh Rane <gdrane@cs.ucla.edu>
Cc: Peter Maydell <peter.maydell@linaro.org>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Problem with translating on ARM and Qemu beginner question
Date: Fri, 25 Nov 2011 19:35:04 +0400 [thread overview]
Message-ID: <201111251935.05055.jcmvbkbc@gmail.com> (raw)
In-Reply-To: <e5b46983-d1af-491f-ad22-ab0a9320624a@mail.cs.ucla.edu>
> 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.
292 42e: bf00 nop
293 430: bcf8 pop {r3, r4, r5, r6, r7}
294 432: bc08 pop {r3}
295 434: 469e mov lr, r3
296 436: 4770 bx lr
Or you can find physical address under $sp, and then via monitor command 'info mtree' check whether there's physical memory by that address.
To find physical address you can either uncomment #define DEBUG_TLB in the exec.c to make it print virtual-to-physical translations or
set breakpoint at cpu_arm_handle_mmu_fault and inspect address and phys_addr values.
Thanks.
-- Max
next prev parent reply other threads:[~2011-11-25 15:35 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <519552ce-93df-4c90-82c6-1938d72bff72@mail.cs.ucla.edu>
2011-11-25 10:27 ` [Qemu-devel] Problem with translating on ARM and Qemu beginner question Gauresh Rane
2011-11-25 11:39 ` Peter Maydell
2011-11-25 12:33 ` Gauresh Rane
2011-11-25 12:47 ` Peter Maydell
2011-11-25 13:04 ` Max Filippov
2011-11-25 14:13 ` Gauresh Rane
2011-11-25 15:35 ` Max Filippov [this message]
2011-11-25 15:40 ` Peter Maydell
2011-11-26 19:37 ` Gauresh Rane
2011-11-26 23:31 ` Gauresh Rane
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