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Date: Sun, 14 Nov 1999 15:49:57 -0700
From: Ryan Bradetich <rbradetich@uswest.net>
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Subject: [parisc-linux] arch/parisc/kernel/realmode_setup.c Question
List-ID: <linux-parisc.vger.kernel.org>

Paul,

I have started working on getting the kernel to boot on the PA2.0
architecture again, and I see the you and others have been doing
lots of work with the initialization code.  (Nice job to everyone btw,
the code is a lot easier to figure out for a newbie like me! :)

I was looking at the following section of code and I have a
discrepancy that I wanted to make you aware of.  I don't know how
to fix it yet, but I will continue to look.

I am working on a C200+ which has the PA2.0 processor, so in the
the following section of code it should give me an error during the
BTLB initialization, but during the PDC_BTLB_INSERT pret is set
to 0, so the check for non-PA1.1 architecture's fail.

I will continue to look through the documentation that has been
previously pointed out, and the devresource page  pointed out by
Frank Rowand to see if I can find a solution to the problem.

Thanks,

Ryan Bradetich


[Taken from arch/parisc/kernel/realmode_setup.c]

 /* This whole VM setup stuff may be removed ultimately.  It seems
   * to me that once the TLB miss handlers are ready, we just switch
   * to VM and let them handle TLB population -PB
   */

  pret = (*PAGE0->mem_pdc)(
  PDC_BLOCK_TLB,
  PDC_BTLB_INSERT,
  0x00000000,  /* MS bits, virt page number */
  0xc0000,  /* LS bits, virt page number */
  0x00000000,  /* Physical page number */
  4096,   /* # pages to map */
  0x03000000,  /* access rights, etc... */
  0);   /* slot number */

  if (pret != 0)
 {
       mprintf("PDC_BTLB_INSERT returned %d\n", pret);
      if (pret == -1)
     {
        mprintf("Looks like there's no BTLB on this box, so it's
probably\n"
                       "either PA1.0 or PA2.0.  In any case we're
screwed for now\n");
        led_flash();
     }
}