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--- grub-0.97.orig/stage2/asm.S 2004-06-19 18:55:22.000000000 +0200
+++ grub-0.97/stage2/asm.S 2006-04-21 11:10:52.000000000 +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
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