Re: About support for rtVAX300

["Michael L. Hitch" <mhitch%lightning.msu.montana.edu@localhost>]

On Fri, 11 Jan 2013, Holm Tiffe wrote:

> On the rtvax is a register for the TIL311 Display, I can write an
> ~0xa to 0x201ffffe and see an 'A', with that I've tried to trace
> the startup code a little, but I get lost in pmap_bootstrap() called from
> locore.c.
> On the very last instruction in pmap_bootstrap()
>
>            VM_FREELIST_DEFAULT);
>        mtpr(sysptsize, PR_SLR);
>        rpb.sbr = mfpr(PR_SBR);
>        rpb.slr = mfpr(PR_SLR);
>        rpb.wait = 0;   /* DDB signal */
>
>          *(int *)(0x201ffffe)=0xf-3; /* Holm */
>
>        mtpr(1, PR_MAPEN);
>
>         *(int *)vax_map_physmem(0x201ffffe,1)=0xf-4; /* Holm */
> }
>
> Nothing happens anymore and I get a trap or something like this..
> I never see that '4', regardless if I try vax_map_physmem or not.
> Is vax_map_physmem() the right thing to this time?

  vax_map_physmem() maps the whole page, so will return the virtual 
address of the page that contains 0x201ffffe, so you will be writing to 
0x201ffe00 (if I've calculated the bits right).

Mike

--
Michael L. Hitch                        mhitch%montana.edu@localhost
Computer Consultant
Information Technology Center
Montana State University        Bozeman, MT     USA