Re: Accessing DRAM on the EBSA-285 from PCI

[Russell King - ARM Linux Admin]

Philip Blundell writes:
> >1)  Change the line to set it as high as possible.  The 21285 data sheet
> >has 256 MB (value = 0x0ffc0000) as the highest value listed.  This would
> >create a huge window but shold allow most anything.
> 
> I think that should be fine.  We ought to check the value of PCI_CFN in there 
> and so long as it's set, we can pile in and set whatever values we like.  If 
> it's clear then we shouldn't muck with any of the BARs at all.  The SDRAM 
> window is actually 512MB aligned at the moment.

Correction: it would be better to tell the 21285 how much SDRAM you have so
that you can use it's features to catch out of bounds accesses which could
trample over the kernel.  The SDRAM window is actually at a fixed address
in PCI space and I don't see what 'at the moment' needs to be there. ;)
   _____
  |_____| ------------------------------------------------- ---+---+-
  |   |        Russell King       [EMAIL PROTECTED]      --- ---
  | | | |  http://www.arm.linux.org.uk/~rmk/armlinux.html    /  /  |
  | +-+-+                                                     --- -+-
  /   |               THE developer of ARM Linux              |+| /|\
 /  | | |                                                     ---  |
    +-+-+ -------------------------------------------------  /\\\  |
unsubscribe: body of `unsubscribe linux-arm' to [EMAIL PROTECTED]