Page table -> SDR1

Sébastien Côté scote1 at
Thu Feb 15 06:28:40 EST 2001

Hello again,

Can someone explain me how the base address for the page table is set ?
Looking at hashtable.S, it should be set to 0x180000 and be 256 kB long.
However, when SDR1 is set in turn_on_mmu (head.S), they use _SDR1 to set
the value but I couldn't find anywhere where _SDR1 is set!

Also, when I check the value in the register SRD1, the HTABORG part (bits
0-15) show 0xE so this isn't 0x180000.  Finally, the value of HTABMASK
(bits 23-31) doesn't correcpond to what is recommended in the PowerPC book
from Motorola for 32 MB of RAM and a 256 kB page table.

To me, it seems like the page table isn't set up correctly but since I
don't really understand how it is done, maybe I'm wrong.  I would also be
very surprised to get that far (jumping to the first instruction of init)
without page table.  A little help about this would be very appreciated.

Sébastien Côté

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