MMU and BDI2000

[Rudolf Ladyzhenskii]

Hi,

I had same problem and used Dan's suggestion to get it working. Here is an
extract from his e-mail:

Add this right after the 'bl load_up_mmu':


        /* Add helper information for the Abatron bdiGDB debugger.
         * We do this here because we know the mmu is disabled, and
         * will be enabled for real in just a few instructions.
         */
        lis     r5, abatron_pteptrs at h
        ori     r5, r5, abatron_pteptrs at l
        stw     r5, 0xf0(r0)    /* This much match your Abatron config */
        lis     r6, swapper_pg_dir at h
        ori     r6, r6, swapper_pg_dir at l
        tophys(r5, r5)
        stw     r6, 0(r5)

You also have to define abatron_pteptrs as global.
This works fine on the 8260 with 2.4.4 kernel.

Rudolf


> -----Original Message-----
> From: Subodh Nijsure [mailto:SNijsure at SkyStream.com]
> Sent: Thursday, December 13, 2001 1:43 PM
> To: 'Wolfgang Denk'; Michael Habermann
> Cc: linuxppc-embedded at lists.linuxppc.org
> Subject: RE: MMU and BDI2000
>
>
>
> Hello,
>
> I have kernel 2.4.4 and I do have MMU XLAT and latest BDI
> firmware from
> Abatron
> and I am  not able to get translation to work. I have tried
> the following
>
> target remote bdi:2001
> b start_here
>
> p &swapper_pg_dir
>
> then at BDI2000 telnet prompt,
>
> mm 0xf0 <address_swapper_pg_dir>
>
> that didn't help.
>
> I got the latest 2.4 _devel kernel and there are lot of
> changes that I need
> to merge into my source, I was looking for a short term fix to get
> translation
> to work. Has anybody gotten gdb to work correctly with
> Abatron 2000 on linux
> 2.4.4 kernel?
>
>
> /Subodh
>
> -----Original Message-----
> From: Wolfgang Denk [mailto:wd at denx.de]
> Sent: Friday, September 14, 2001 4:30 AM
> To: Michael Habermann
> Cc: linuxppc-embedded at lists.linuxppc.org
> Subject: Re: MMU and BDI2000
>
>
>
> In message <5.1.0.14.0.20010914174808.026db880 at pop.gmx.de> you wrote:
> >
> > I've not found a BDI newsgroup or FAQ so I'm sorry
>
> Maybe we should start a mailing list.
>
> > But I get problems debugging variables. The BDI often prints:
> > '*** MMU: address translation for 0xC100B288 failed',
> ...
> > [TARGET]
> > CPUTYPE	    MPC800
> > CPUCLOCK    25000000    ;the CPU clock rate after
> processing the init list
> > BDIMODE     AGENT       ;the BDI working mode (LOADONLY | AGENT)
> > BREAKMODE   HARD        ;SOFT or HARD, HARD uses PPC
> hardware breakpoints
> > MMU XLAT
>
> Are you using latest BDI2000 firmware?
>
> I'm missing a PTBASE definition in this section  -  without  it  only
> default  translation  is  enabled.  See  the  BDI2000  user's manual,
> Section "3.2.2 Part [TARGET]" (Entries "MMU XLAT  [kb]"  and  "PTBASE
> addr") and Section "3.3.4 Embedded Linux MMU Support".
>
> Please note that the 2.4.4 kernel on our  FTP  server  does  not  yet
> include  the  automatic  update  of  the  BDI  page table information
> structure mentioned in the BDI2000 manual. We will have this  in  the
> next version (as soon as it's running stable).
>
> Wolfgang Denk
>
> --
> Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
> Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
> Is a computer language with goto's totally Wirth-less?
>
>

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