Index: arch/amd64/src/context.S
===================================================================
--- arch/amd64/src/context.S	(revision b524f8160fac39354818c5041d71a7fbb61fa89a)
+++ arch/amd64/src/context.S	(revision b524f8160fac39354818c5041d71a7fbb61fa89a)
@@ -0,0 +1,78 @@
+#
+# Copyright (C) 2001-2004 Jakub Jermar
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# - Redistributions of source code must retain the above copyright
+#   notice, this list of conditions and the following disclaimer.
+# - Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+# - The name of the author may not be used to endorse or promote products
+#   derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+.text
+
+.global context_save
+.global context_restore
+
+#include "context_offset.h"
+
+## Save current CPU context
+#
+# Save CPU context to the kernel_context variable
+# pointed by the 1st argument. Returns 1 in EAX.
+#
+context_save:
+	movq (%rsp), %rdx     # the caller's return %eip
+	# In %edi is passed 1st argument
+	movq %rdx, OFFSET_PC(%rdi)
+	movq %rsp, OFFSET_SP(%rdi)
+	
+	movq %rbx, OFFSET_RBX(%rdi)
+	movq %rbp, OFFSET_RBP(%rdi)
+	movq %r12, OFFSET_R12(%rdi)
+	movq %r13, OFFSET_R13(%rdi)
+	movq %r14, OFFSET_R14(%rdi)
+	movq %r15, OFFSET_R15(%rdi)
+	
+	xorq %rax,%rax		# context_save returns 1
+	incq %rax
+	ret
+
+
+## Restore current CPU context
+#
+# Restore CPU context from the kernel_context variable
+# pointed by the 1st argument. Returns 0 in EAX.
+#
+context_restore:	
+	movq OFFSET_R15(%rdi), %r15
+	movq OFFSET_R14(%rdi), %r14
+	movq OFFSET_R13(%rdi), %r13
+	movq OFFSET_R12(%rdi), %r12
+	movq OFFSET_RBP(%rdi), %rbp
+	movq OFFSET_RBX(%rdi), %rbx	
+	
+	movq OFFSET_SP(%rdi), %rsp   # ctx->sp -> %rsp
+	
+	movq OFFSET_PC(%rdi), %rdx
+	movq %rdx,(%rsp)
+
+	xorq %rax,%rax		# context_restore returns 0
+	ret
Index: arch/amd64/src/dummy.s
===================================================================
--- arch/amd64/src/dummy.s	(revision 8fc0d4553a1a8e382979ca225a7ae2d3e376d1a2)
+++ arch/amd64/src/dummy.s	(revision b524f8160fac39354818c5041d71a7fbb61fa89a)
@@ -30,4 +30,5 @@
 
 .global memcopy
+.global memcpy
 .global cpu_priority_high
 .global cpu_priority_low
@@ -35,6 +36,4 @@
 .global cpu_priority_restore
 .global memsetb
-.global context_save
-.global context_restore
 .global userspace
 .global before_thread_runs_arch
@@ -54,5 +53,7 @@
 .global frame_arch_init
 .global dummy
+.global asm_delay_loop
 
+memcpy:	
 memcopy:
 cpu_priority_high:
@@ -61,6 +62,5 @@
 cpu_priority_read:
 memsetb:
-context_save:
-context_restore:
+asm_delay_loop:	
 before_thread_runs_arch:
 userspace: