X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=arch%2Fx86_64%2Fkernel%2Fhead.S;h=598a4d0351fc15190274f504995ec738f0b63cec;hp=c9739ca81d062e31c30aed9ac07df6f921fe5c1f;hb=42eaf0d8f2e7b8201afc00b0ebe1bd89ea51d42d;hpb=dd1a47c21ee4f4f682285ad9d4624d2cec436f93

diff --git a/arch/x86_64/kernel/head.S b/arch/x86_64/kernel/head.S
index c9739ca81d06..598a4d0351fc 100644
--- a/arch/x86_64/kernel/head.S
+++ b/arch/x86_64/kernel/head.S
@@ -5,8 +5,6 @@
  *  Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
  *  Copyright (C) 2000 Karsten Keil <kkeil@suse.de>
  *  Copyright (C) 2001,2002 Andi Kleen <ak@suse.de>
- *
- *  $Id: head.S,v 1.49 2002/03/19 17:39:25 ak Exp $
  */
 
 
@@ -165,6 +163,20 @@ startup_64:
 	 */
 	lgdt	cpu_gdt_descr
 
+	/* set up data segments. actually 0 would do too */
+	movl $__KERNEL_DS,%eax
+	movl %eax,%ds
+	movl %eax,%ss
+	movl %eax,%es
+
+	/*
+	 * We don't really need to load %fs or %gs, but load them anyway
+	 * to kill any stale realmode selectors.  This allows execution
+	 * under VT hardware.
+	 */
+	movl %eax,%fs
+	movl %eax,%gs
+
 	/* 
 	 * Setup up a dummy PDA. this is just for some early bootup code
 	 * that does in_interrupt() 
@@ -175,24 +187,21 @@ startup_64:
 	shrq	$32,%rdx
 	wrmsr	
 
-	/* set up data segments. actually 0 would do too */
-	movl $__KERNEL_DS,%eax
-	movl %eax,%ds	
-	movl %eax,%ss
-	movl %eax,%es
-			
 	/* esi is pointer to real mode structure with interesting info.
 	   pass it to C */
 	movl	%esi, %edi
 	
 	/* Finally jump to run C code and to be on real kernel address
 	 * Since we are running on identity-mapped space we have to jump
-	 * to the full 64bit address , this is only possible as indirect
-	 * jump
+	 * to the full 64bit address, this is only possible as indirect
+	 * jump.  In addition we need to ensure %cs is set so we make this
+	 * a far return.
 	 */
 	movq	initial_code(%rip),%rax
-	pushq	$0		# fake return address
-	jmp	*%rax
+	pushq	$0		# fake return address to stop unwinder
+	pushq	$__KERNEL_CS	# set correct cs
+	pushq	%rax		# target address in negative space
+	lretq
 
 	/* SMP bootup changes these two */
 	.align	8
@@ -371,7 +380,7 @@ ENTRY(cpu_gdt_table)
 	.quad	0,0			/* TSS */
 	.quad	0,0			/* LDT */
 	.quad   0,0,0			/* three TLS descriptors */ 
-	.quad	0			/* unused */
+	.quad	0x0000f40000000000	/* node/CPU stored in limit */
 gdt_end:	
 	/* asm/segment.h:GDT_ENTRIES must match this */	
 	/* This should be a multiple of the cache line size */