Re: [ECOS] Re: Problem on allocate PCI memory space...

["Ling Su" <lingsu at palmmicro dot com>]

Nick wrote,
> >
> > If you take a look at the registers and the specific instruction that
> > the exception occured on you should be able to work out exactly what
> > address it was trying to access, and the value in the cause register
> > should tell you what exception it actually was. If it's a TLB
> > exception then maybe the MMU setup needs changing, if its
> > a bus exception then the problem lies in the hardware setup.
> >

Ling Su wrote,
>
> I checked the "cause" register, the value is 0x800C, which means the TLB
> Miss Exception(store) occurs. I dobut if I only change the NUMB_PG to 16
the
> TLB will be enough to handle 512MB space, could you please take a look at
> the TLB part. I will also check this by myself.
>

Dear Nick and Jifl,

After carefully checking the result of my pci test program, I am pretty sure
the Segmentation Fault is caused by TLB setup problem, but I still didn't
find the point why TLB can not map address above 0x8FFF_FFFF. I have several
small questions here,

<1>. What is the meaning of NUMB_PG, what is relationship to TLBENTRIES
(32)?
<2>. I want to trace the TLB inistialization part code, unfortunately I
found I can not set breakpoint in the hal_mmu_setup Macro, I tried the
hal_mmu_init in Vector.S, it doesn't work as well. There is a _start funtion
in vector.S, it calls hal_cpu_init, hal_diag_init, hal_mmu_init.... etc... I
can set a breakpoint on hal_cpu_init, but I can not set anything on the next
line, hal_diag_init and hal_mmu_init. I don't quite understand this, where I
can setup a break point for the MMU setup routine, so that I can step by
step go through the procedure? Could you please drop me a hint?
<3>. Should I use STATIC MMU table? Will it bring any diffrence? Actually I
did try it, result is the same, just curious.

Thanks a lot!

Rgds,
-Ling