patch for PPC Old World Macintosh

[Hollis Blanchard]

Seeing that Marco did the hard work of porting grub2 to New World Power 
Mac, I though I'd try to support Old World (i.e. Macs with sucky Open 
Firmware).

'quik' is the OF-based Old World bootloader for Linux. Unfortunately a 
stage1 is needed due to firmware limitations, so I am using a slightly 
modified quik stage1 (it now "claims" the memory it uses). I have also 
slightly modified quik installer (which installs the stage1 to disk) so 
that it sets the stage2 base to be 2M, grubof's link address. Long-term 
it may be worthwhile to copy quik's stage1 into grub2's source tree, 
but the quik *installer* is appalling code and probably warrants a 
from-scratch rewrite (maybe NetBSD's installboot(8) meets our needs).

This patch adds basic support for Old World, enough to get to the 
rescue or normal prompt. Most of the problems were related to the 
memory layout. I have not yet fixed loading from disk; it shouldn't be 
hard but I thought I should submit what I have working now.

This patch uses the "/memory/available" property to find memory. Works 
for me, but it is not very conservative. I have it on good authority 
that Old World firmware defaults to 4M-5M, so I think this is ok 
until/unless we find a machine that doesn't work...

ALIGN_UP doesn't need to be in mm.h, but it seemed as good as any place 
to put it.

-Hollis

2004-08-29      Hollis Blanchard        <address@hidden>
	* boot/powerpc/ieee1275/cmain.c: check for quik stage1. If present, 
use r3 rather
	than r5 as the Open Firmware entry point; claim grub's BSS range since 
quik
        stage1 doesn't; claim OF's memory range for it (since it doesn't);
	* boot/powerpc/ieee1275/crt0.S: zero BSS here since it is required on 
Old World pmac.
        If it isn't required, it can't hurt anyways.
        Pass r3-r5 through unchanged to let cmain() detect quik.
        * include/grub/mm.h: add ALIGN_UP macro.
	* kern/powerpc/ieee1275/init.c: add a "trap" to abort() so we drop 
back to Open
        Firmware.
	Claim and use all memory that's listed as available in the 
/memory/available property.

grub-oldworld-mem.diff
Description: Binary data