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[Qemu-devel] Re: target-sparc/TODO
From: |
Artyom Tarasenko |
Subject: |
[Qemu-devel] Re: target-sparc/TODO |
Date: |
Thu, 20 Aug 2009 11:44:48 +0200 |
>> Particularly I'm interested if
>>
>> jmp %l1, %g4, %g0
>>
>> may behave other than on a real hw.
>
> No, if rd is %g0, the current PC will not be written anywhere (not by
> real HW either).
The reason I asked is the two following pieces of code work
differently on a real and emulated SS-5. On a real one spacel! does an
asi write, and spacel@ does an asi read, and under qemu spacel! seems
to do nothing, and spacel@ returns its second parameter multiplied by
4. Both of them don't even try to call an [unimplemented] asi
operation, I've runned the tests with mmu and asi debug turned on.
Real SS-5:
ok 0 0 spacel@ .
Data Access Error
ok 0 20 spacel@ .
0
ok 12345678 0 20 spacel!
ok 0 20 spacel@ .
12345678
ok
qemu SS-5:
ok 0 0 spacel@ .
0
ok 0 20 spacel@ .
80
ok 12345678 0 20 spacel!
ok 0 20 spacel@ .
80
ok
I don't know sparc asm good enogh, but qemu behavior seems to be
logical: in the first case I see no store op, and there are shifts
which would multiply by 4:
ok see spacel!
code spacel!
ffd26e0c ld [%g7], %l2
ffd26e10 add %g7, 4, %g7
ffd26e14 ld [%g7], %l0
ffd26e18 add %g7, 4, %g7
ffd26e1c sll %g4, 2, %g4
ffd26e20 call ffd26e24
ffd26e24 add %g0, 14, %l1
ok ffd26e24 dis
ffd26e24 add %g0, 14, %l1
ffd26e28 add %o7, %l1, %l1
ffd26e2c jmp %l1, %g4, %g0
ffd26e30 ba ffd26f68
ok
ok see spacel@
code spacel@
ffd26830 ld [%g7], %l0
ffd26834 add %g7, 4, %g7
ffd26838 sll %g4, 2, %g4
ffd2683c call ffd26840
ffd26840 add %g0, 14, %l1
ok ffd26840 dis
ffd26840 add %g0, 14, %l1
ffd26844 add %o7, %l1, %l1
ffd26848 jmp %l1, %g4, %g0
ffd2684c ba ffd26984
The code is identical on a real and emulated SS.
It must be the jump, which jumps differently on a real hw and under
qemu. Do you see from the code where the jump would jump to, or maybe
you have a suggestion how to check where the jump jumps to on the real
hw?
- [Qemu-devel] target-sparc/TODO, Artyom Tarasenko, 2009/08/17
- [Qemu-devel] Re: target-sparc/TODO, Blue Swirl, 2009/08/17
- [Qemu-devel] Re: target-sparc/TODO, Artyom Tarasenko, 2009/08/19
- [Qemu-devel] Re: target-sparc/TODO, Blue Swirl, 2009/08/19
- [Qemu-devel] Re: target-sparc/TODO,
Artyom Tarasenko <=
- [Qemu-devel] Re: target-sparc/TODO, Blue Swirl, 2009/08/20
- [Qemu-devel] Re: target-sparc/TODO, Artyom Tarasenko, 2009/08/21
- [Qemu-devel] Re: target-sparc/TODO, Artyom Tarasenko, 2009/08/21
- [Qemu-devel] Re: target-sparc/TODO, Blue Swirl, 2009/08/21
- [Qemu-devel] Re: target-sparc/TODO, Artyom Tarasenko, 2009/08/21
- Re: [Qemu-devel] Re: target-sparc/TODO, Igor Kovalenko, 2009/08/21
- Re: [Qemu-devel] Re: target-sparc/TODO, Artyom Tarasenko, 2009/08/21
- [Qemu-devel] Re: target-sparc/TODO, Blue Swirl, 2009/08/22
- [Qemu-devel] Re: target-sparc/TODO, Artyom Tarasenko, 2009/08/22
- Re: [Qemu-devel] Re: target-sparc/TODO, Robert Reif, 2009/08/22