Access physical memory via mmap() on ppc440epx.

[Josh Boyer]

On Tue, 2008-04-01 at 14:12 -0700, Leonid wrote:
> Hi:
> 
> I am trying to read from NOR flash, located on address 0xfc000000, on my

It's at 0x1fc000000 IIRC.

> TLB entries look strange though. That what it was on u-boot stage:
> 
> 440EPx>tlb 0 10
> IDX TID      EPN  SIZE VTS          RPN   USER WIMGE USRSVC
>  0 : 00 40000000 256MB V0 -> 0_00000000 U:0000 -I-G- XWRXWR
>  1 : 00 00000000 256MB V0 -> 0_00000000 U:0000 -I-G- XWRXWR
>  2 : 00 c0000000 256MB V0 -> 1_c0000000 U:0000 -I-G- XWRXWR
>  3 : 00 f0000000 256MB V0 -> 1_f0000000 U:0000 WI-G- XWRXWR

See.  Virtual is 0xf0000000, physical is 0x1f0000000.

> On Linux stage it looks rather different:

I don't even see your entry in here.  Likely because the TLB is small
and it's gone by the time you do the dump

> Probably under MMU it should look this way? How to use mmap() then?

Try mmap64 on the real physical address and see if that helps.

josh