[linuxsh-dev] Re: System reset while INIT processing

[Masahiro A. <m-...@aa...>]

On Thu, 12 Jul 2001 22:14:54 +0900
Masahiro Abe <m-...@aa...> wrote:

> Sorry for too much posts today. Hopefully this will be today's last one.
> 
> I've learned how to use JTAG debugger, and managed to get some
> information at system reboot. This is what I've found:
> When reboot (PC<-0xa0000000),
> - SPC points inside memcpy(arch/sh/lib/memcpy.S), but the exact address
> changes time to time.
> - EXPEVT is 0x140, which is multiple TLB(either data or instruction) hit
> exception.
> - If it means something, both SR and SSR are 0x700000F1
> 
> I can't interpret those yet. If anyone have thought about something
> related, I deadly would like to know.

Some more reports.
- calling sequence until reboot is
  copy_user_page(arch/sh/mm/cache.c)
    +-update_mmu_cache(arch/sh/mm/fault.c)
    +-copy_page : #defined as memcpy(arch/sh/lib/memcpy.S)
  Last two functions are called at line 588 and 589 of cache.c,
  respectively.
- most of the time, exception occurs at line 86 of memcpy.S, which is
	mov.l	r1,@-r0
  at this time, @r0=0xc0002ffc
- TEA has 0xc0002ffc at the time of exception/reboot. So, this is
  multiple data TLB hit exception.
- 0xc0002ffc is within the area that p3_cache_init allocated with
  remap_area_pages. This area is from 0xc0000000 to 0xc0003fff.

I still can't understand what is causing this exception, and why this
doesn't happen on SolutionEngine or other SH4 system.
I appreciate any input on this.

+-------------------------------------+
| Masahiro Abe, Software Engineer     |
| A&D Co., Ltd. of Tokyo, Japan       |
| mailto:m-...@aa...            |
+-------------------------------------+
|This is my opinion, not my employer's|
+-------------------------------------+