On 28 October 2014 13:23, Liviu Ionescu <i...@livius.net> wrote:
>
> On 28 Oct 2014, at 14:57, Peter Maydell <peter.mayd...@linaro.org> wrote:
>
>> On 28 October 2014 12:52, Liviu Ionescu <i...@livius.net> wrote:
>>>
>>> On 28 Oct 2014, at 14:45, Peter Maydell <peter.mayd...@linaro.org> wrote:
>>>
>>>>> qemu: Unsupported SemiHosting SWI 0x00
>>>>> R00=00000000 R01=00000000 R02=00000000 R03=00000000
>>>>> R04=00000000 R05=00000000 R06=00000000 R07=200ffed8
>>>>> R08=00000000 R09=00000000 R10=00000000 R11=00000000
>>>>> R12=00000000 R13=200ffed8 R14=000022c5 R15=0000157c
>>>>> PSR=60000173 -ZC- T svc32
>>>>> Abort trap: 6
>>>>
>>>> What code sequence and which semihosting function are
>>>> you trying to use here?
>>>
>> ...
>> Can you give the disassembly of the actual code making
>> the semihosting request, please? As you can see we seem
>> to have interpreted this as a semihosting function zero,
>> not 4, but it's hard to see why without seeing what the
>> assembly instructions are that your code is executing.
>
> right, I did some more tests, and the the actual code is:
>
> 00001564 <_ZN3hal7cortexm4diag11SemiHosting4BKPTEiPvS3_>:
> {
>
> //
> ======================================================================
> int
> SemiHosting::BKPT(int op, void* p1, void* p2)
> {
> 1564: b480 push {r7}
> 1566: b085 sub sp, #20
> 1568: af00 add r7, sp, #0
> 156a: 60f8 str r0, [r7, #12]
> 156c: 60b9 str r1, [r7, #8]
> 156e: 607a str r2, [r7, #4]
> register int r0 asm("r0");
> register int r1 asm("r1") __attribute__((unused));
> register int r2 asm("r2") __attribute__((unused));
>
> r0 = op;
> 1570: 68f8 ldr r0, [r7, #12]
> r1 = (int) p1;
> 1572: 68bb ldr r3, [r7, #8]
> 1574: 4619 mov r1, r3
> r2 = (int) p2;
> 1576: 687b ldr r3, [r7, #4]
> 1578: 461a mov r2, r3
> asm volatile(""
> " bkpt 0xAB \n"
> : "=r"(r0)
> :
> :
> );
> 157a: beab bkpt 0x00ab
> return r0;
> 157c: 4603 mov r3, r0
> }
> 157e: 4618 mov r0, r3
> 1580: 3714 adds r7, #20
> 1582: 46bd mov sp, r7
> 1584: f85d 7b04 ldr.w r7, [sp], #4
> 1588: 4770 bx lr
> 158a: bf00 nop
Hmm. That code looks OK, but as you can see from the register
dump, QEMU thinks that at the point where it complained
r0 is zero.
> I would check the way "bkpt 0x00ab" is processed.
Do you have a test binary (plus qemu command line) you
can send me?
thanks
-- PMM
