Re: Booting without ofwboot

[Jorge Acereda <jacereda%gmail.com@localhost>]

On Sat, 23 Oct 2004 11:34:22 -0700, Chuck Silvers <chuq%chuq.com@localhost> 
wrote:
> On Sat, Oct 23, 2004 at 06:18:56PM +0200, Jorge Acereda wrote:

> as I recall, the FirePower box loaded ofwboot and the kernel, but then
> the kernel didn't print anything... similar to what you saw on your box.

Hi,

I spent some time trying to figure out what the problem was, I can now
reach the point where the kernel asks for a boot partition. It seems
there's an issue with openfirmware(). My PPC skills are weak, so I
would appreciate any help in tracking the problem.

Here is the dirty patch, it is just what openfirmware() looked like
for ofppc in 1.6 days:

diff -u -r1.2 ofw_subr.S
--- sys/arch/powerpc/oea/ofw_subr.S     13 Feb 2003 15:02:49 -0000      1.2
+++ sys/arch/powerpc/oea/ofw_subr.S     24 Oct 2004 19:42:38 -0000
@@ -92,6 +92,33 @@
  */
        .text
 ENTRY(openfirmware)
+#if 1 /* XXX */
+       mflr    0                       /* save return address */
+       stw     0,4(1)
+       stwu    1,-16(1)                /* setup stack frame */
+
+       mfmsr   4                       /* save msr */
+       stw     4,8(1)
+
+       lis     4,openfirmware_entry@ha /* get firmware entry point */
+       lwz     4,openfirmware_entry@l(4)
+       mtlr    4
+
+       li      0,0                     /* turn off any ints/mmu/etc. */
+       mtmsr   0
+       isync
+
+       blrl                            /* call OpenFirmware */
+
+       lwz     4,8(1)                  /* restore msr */
+       mtmsr   4
+       isync
+
+       lwz     1,0(1)                  /* and return */
+       lwz     0,4(1)
+       mtlr    0
+       blr
+#endif         
        mflr    0                       /* save return address */
        stw     0,4(1)
        stwu    1,-16(1)                /* setup stack frame */