Re: [Qemu-devel] [RFC PATCH v4 5/5] target/ppc: support single stepping with KVM HV

[Alexey Kardashevskiy <aik@ozlabs.ru>]

Are you reposting this any time soon?

In meanwhile I hit a problem when I cannot step over the "stdu" instruction.

I basically put this:
stdu    r1,-368(r1)

and "ni" in gdb does not stop on the next instruction which is quite
confusing. Ideas?


On 20/03/2019 12:42, Alexey Kardashevskiy wrote:
> 
> 
> On 20/03/2019 01:32, Fabiano Rosas wrote:
>> Alexey Kardashevskiy <aik@ozlabs.ru> writes:
>>
>>> Looks good to me, does not break what already works. However I cannot
>>> debug SLOF real mode and I am not sure why.
>>>
>>> (gdb) set endian big
>>>
>>> The target is assumed to be big endian
>>> (gdb) b *0x3f00
>>>
>>> Breakpoint 2 at 0x3f00
>>
>> I think I'm missing the point here. Why 0x3f00?
> 
> Because I am stupid and did not realize that 0x3f00 is a relative offset
> and 0x4000 is the correct address which works.
> 
> 
> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> 
> 
>>
>> (qemu) info roms
>> addr=0000000000000000 size=0x0e22b8 mem=ram name="...qemu/slof.bin"                               
>> addr=0000000000400000 size=0x17976d0 mem=ram name="...vmlinux"
>>
>>
>> $ objdump -d board-qemu/llfw/stage1.elf | grep "_start>"
>> 0000000000000100 <__start>:
>>      100:       48 00 3f 00     b       4000 <_start>
>> 0000000000004000 <_start>:
>>
>>
>> Thread 1 hit Breakpoint 3, _start () at startup.S:82
>> (gdb) p/x $pc
>> $1 = 0x4000
>> (gdb) si
>> (gdb) p/x $pc
>> $3 = 0x4004
>> (gdb) c
>> Thread 1 hit Breakpoint 4, early_c_entry (start_addr=49056, fdt_addr=49024) at stage2.c:202
>> (gdb) p/x $pc
>> $4 = 0x4d18
>>
> 

-- 
Alexey