On Jan 14, 2008 1:37 AM, Enno Lübbers <[EMAIL PROTECTED]> wrote: > Hello David, > > Am 14.01.2008 um 06:12 schrieb David Baird: > > > I'm having trouble with getting Linux to boot farther than early_init. > > [...] > > So, I experimented further and discovered that different memory > > regions seem to be aliased on to each other every 2*32*256 bytes. > > > This sounds either like a wrong programming of an BRx/ORx memory > controller register pair (which, AFAIK, the PPC405 does not have), or > like a messed up address map in EDK. My guess is that an optimized/ > sloppy implementation of the address decoder for some peripheral in an > EDK system could produce something like you described; or there's a > block RAM that's attached to a controller in the wrong way; or the > bank/address parameters of the DDR controller don't match the physical > setup... there's a lot that can go wrong obviously on a configurable > SoC.
What has been confusing me is that I am unable to reproduce the problem in real mode. I can only reproduce the problem in virtual mode. This leads me to believe, perhaps mistakenly, that the hardware is implemented okay. OTOH, neither can I see anything wrong with the software. > Can you be more specific about your hardware platform? Is this a > reference design? What board are you using? I am currently testing code on the ML403 evaluation board. I used the Base System Builder in EDK to create the hardware design and DDR SDRAM is being used as the main RAM starting at address 0x00000000 and also with OCM BRAM mapped at the very end of the address space (so that 0xfffffffc can contain code to execute on startup). I am now trying to experiment with the hardware and see if I can find a hardware reference design. I will let you know what I figure out. -David _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded
