Access physical memory via mmap() on ppc440epx.

Leonid Leonid at
Thu Apr 3 09:50:33 EST 2008

Hi, Josh:

I have resolved my kernel driver problem, it was my own bug, didn't have
anything to do with memory remapping itself. Your suggestion to move to
ioremap64() did resolve problem completely.

I still need investigate mmap() crash. Apparently switch to mmap64()
didn't help, but it could be some another bug, I'll double check.



-----Original Message-----
From: at
[ at] On Behalf
Of Leonid
Sent: Tuesday, April 01, 2008 9:30 PM
To: Josh Boyer
Cc: linuxppc-embedded at
Subject: RE: Access physical memory via mmap() on ppc440epx.

Hi, Josh:

Thank you for your suggestion. Somehow it didn't work with mmap (may be,
my mistake, I'll double check), however it partially helped me with my
another problem.

I have kernel driver where I need read/write some HW device, connected
on address 0xea000000, chip select 4. This chip select configured
properly, here are EBC registers:

440EPx>rd ebc0_b4cr
ebc0_b4cr: 0xea01a000  -368992256
440EPx>rd ebc0_b4ap
ebc0_b4ap: 0x03037000  50556928

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