$NetBSD: patch-aa,v 1.3 2004/12/04 11:54:54 blymn Exp $

--- src/process.S.orig	2001-10-05 06:44:08.000000000 +0930
+++ src/process.S
@@ -400,7 +400,83 @@ returnto:
 	.end	returnto
 #endif /* mips */
 
-#ifdef	i386
+#if	defined(__amd64)
+
+#include <machine/asm.h>
+
+/*
+   savecontext(f, area1, newsp)
+	int (*f)();
+ 	struct savearea *area1;
+	char *newsp;
+
+	f will be in %rdi
+	*area1 will be in %rsi
+	*newsp will be in %rdx
+*/
+	
+        .text
+ENTRY(savecontext)
+	pushq	%rsp
+	pushq	%rax
+	pushq	%rcx
+	pushq	%rdx
+	pushq	%rbx
+	pushq	%rbp
+	pushq	%rsi
+	pushq	%rdi
+	pushq	%r8
+	pushq	%r9
+	pushq	%r10
+	pushq	%r11
+	pushq	%r12
+	pushq	%r13
+	pushq	%r14
+	pushq	%r15
+		
+	movq	%rsp, (%rsi)	/* Store sp in savearea. */
+
+	cmpq	$0, %rdx	/* Check if newsp is NULL */
+	je	L1			/* Don't change the stack if newsp is zero. */
+	movq	%rdx, %rsp
+
+L1:	xorq	%rbp, %rbp		/* clear stackframe */
+	call	*%rdi			/* f(); */
+
+        /* Trigger a segfault, we shouldn't get here anyway. */
+        movq    $0, 0
+
+/*
+  returnto(area2)
+     struct savearea *area2;
+
+	area2 will be in %rdi
+*/
+#define	area2	8
+
+ENTRY(returnto)
+	mov	(%rdi), %rsp	/* Restore stack pointer. */
+	popq	%r15
+	popq	%r14
+	popq	%r13
+	popq	%r12
+	popq	%r11
+	popq	%r10
+	popq	%r9
+	popq	%r8
+	popq	%rdi
+	popq	%rsi
+	popq	%rbp
+	popq	%rbx
+	popq	%rdx
+	popq	%rcx
+	popq	%rax
+	popq	%rsp
+	ret
+
+#endif /* amd64 */
+
+#if	defined(i386)
 		
 /*
    savecontext(f, area1, newsp)