[Bug 811683] Re: 7400, 7410, 7450 cpus vector have wrong exception prefix at reset

[Thomas Huth]

Looking through old bug tickets... can you still reproduce this issue
with the latest version of QEMU? Or could we close this ticket nowadays?


** Changed in: qemu
       Status: New => Incomplete

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Title:
  7400,7410,7450 cpus vector have wrong exception prefix at reset

Status in QEMU:
  Incomplete

Bug description:
  I have a proprietary ROM implementing system calls that are executed
  via the 'SC' instruction.

  I use qemu-0.14.1,

  qemu-system-ppc -M prep -cpu $CPU -bios my_bios -kernel my_kernel

  That works fine on a 604 (CPU=0x00040103) - but does not on an emulated 7400 
(CPU=0x000c0209) or 7450 (CPU=0x80000201). I found that the emulator jumps to 
0x00000c00 instead of 0xfff00c00.
  Probably this is due to a wrong setting in target-ppc/translate_init.c:

  init_excp_604() correctly sets env->hreset_vector=0xfff00000UL;

  but

  init_excp_7400() says env->hreset_vector=0x00000000UL;

  which seems wrong. (the 7400 manual says a hard-reset jumps initializes the
  prefix to 0xfff00000.)

  Likewise, init_excp_7450() (and probably other, related CPUs) are
  wrong.

  Indeed, when I change the value in init_excp_7400() to 0xfff00000UL then
  everything works as expected for me.

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