# --- T2-COPYRIGHT-NOTE-BEGIN ---
# This copyright note is auto-generated by ./scripts/Create-CopyPatch.
# 
# T2 SDE: package/.../grub/mactel.patch
# Copyright (C) 2006 The T2 SDE Project
# 
# More information can be found in the files COPYING and README.
# 
# This patch file is dual-licensed. It is available under the license the
# patched project is licensed under, as long as it is an OpenSource license
# as defined at http://www.opensource.org/ (e.g. BSD, X11) or under the terms
# of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
# --- T2-COPYRIGHT-NOTE-END ---

Pasted together out of the OpenSolaris forum ,-) to allow booting
on Macintosh Intel hardware, such as the MacBooks and the like.

  - Rene Rebe <rene@exactcode.de>

--- grub-0.97/stage2/asm.S.vanilla	2006-05-31 19:43:15.858048750 +0200
+++ grub-0.97/stage2/asm.S	2006-05-31 19:47:11.584780750 +0200
@@ -1651,7 +1651,29 @@
 	jnz	3f
 	ret
 
-3:	/* use keyboard controller */
+3:	/*
+	 * try to switch gateA20 using PORT92, the "Fast A20 and Init"
+	 * register
+	 */
+	mov	$0x92, %dx
+	inb	%dx, %al
+	/* skip the port92 code if it's unimplemented (read returns 0xff) */
+	cmpb	$0xff, %al
+	jz	6f
+
+	/* set or clear bit1, the ALT_A20_GATE bit */
+	movb	4(%esp), %ah
+	testb	%ah, %ah
+	jz	4f
+	orb	$2, %al
+	jmp	5f
+4:	and	$0xfd, %al
+
+	/* clear the INIT_NOW bit; don't accidently reset the machine */
+5:	and	$0xfe, %al
+	outb	%al, %dx
+
+6:	/* use keyboard controller */
 	pushl	%eax
 
 	call    gloop1
@@ -1661,9 +1683,12 @@
 
 gloopint1:
 	inb	$K_STATUS
+	cmpb	$0xff, %al
+	jz	gloopint1_done
 	andb	$K_IBUF_FUL, %al
 	jnz	gloopint1
 
+gloopint1_done:
 	movb	$KB_OUTPUT_MASK, %al
 	cmpb	$0, 0x8(%esp)
 	jz	gdoit
@@ -1684,6 +1709,8 @@
 
 gloop1:
 	inb	$K_STATUS
+	cmpb	$0xff, %al
+	jz	gloop2ret
 	andb	$K_IBUF_FUL, %al
 	jnz	gloop1
 
@@ -1991,6 +2018,11 @@
 ENTRY(console_getkey)
 	push	%ebp
 
+wait_for_key:
+	call	EXT_C(console_checkkey)
+	incl	%eax
+	jz	wait_for_key
+	
 	call	EXT_C(prot_to_real)
 	.code16