Re: [PATCH] fix i486 boot failure due to stale %ds

[H. Peter Anvin]

Urk, -ENOTAWAKEYET.  Try *THIS* patch, please.

	-hpa

diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S
index 2e55923..17e6dec 100644
--- a/arch/x86/boot/pmjump.S
+++ b/arch/x86/boot/pmjump.S
@@ -28,27 +28,37 @@
  * void protected_mode_jump(u32 entrypoint, u32 bootparams);
  */
 protected_mode_jump:
-	xorl	%ebx, %ebx		# Flag to indicate this is a boot
 	movl	%edx, %esi		# Pointer to boot_params table
-	movl	%eax, 2f		# Patch ljmpl instruction
+
+	xorl	%edx, %edx
+	movw	%cs, %dx
+	shll	$4, %edx		# Patch ljmpl instruction
+	addl	%edx, 2f
 	jmp	1f			# Short jump to flush instruction q.
 
 1:
 	movw	$__BOOT_DS, %cx
+	xorl	%ebx, %ebx		# Per protocol
+	xorl	%ebp, %ebp		# Per protocol
+	xorl	%edi, %edi		# Per protocol
 
 	movl	%cr0, %edx
 	orb	$1, %dl			# Protected mode (PE) bit
 	movl	%edx, %cr0
+	
+	.byte	0x66, 0xea		# ljmpl opcode
+2:	.long	3f			# Offset
+	.word	__BOOT_CS		# Segment
 
-	movw	%cx, %ds
-	movw	%cx, %es
-	movw	%cx, %fs
-	movw	%cx, %gs
-	movw	%cx, %ss
+	.code32
+3:
+	movl	%ecx, %ds
+	movl	%ecx, %es
+	movl	%ecx, %fs
+	movl	%ecx, %gs
+	movl	%ecx, %ss
 
 	# Jump to the 32-bit entrypoint
-	.byte	0x66, 0xea		# ljmpl opcode
-2:	.long	0			# offset
-	.word	__BOOT_CS		# segment
-
+	jmpl	*%eax
+	
 	.size	protected_mode_jump, .-protected_mode_jump