diff --git a/xen/arch/x86/boot/x86_32.S b/xen/arch/x86/boot/x86_32.S
index d510c1fa1b..b98e1c72bc 100644
--- a/xen/arch/x86/boot/x86_32.S
+++ b/xen/arch/x86/boot/x86_32.S
@@ -1,5 +1,6 @@
 #include <xen/config.h>
 #include <public/xen.h>
+#include <asm/asm_defns.h>
 #include <asm/desc.h>
 #include <asm/page.h>
 #include <asm/msr.h>
@@ -53,6 +54,7 @@ __start:
         mov     %ecx,%gs
         ljmp    $(__HYPERVISOR_CS),$(1f)-__PAGE_OFFSET
 1:      lss     stack_start-__PAGE_OFFSET,%esp
+        add     $(STACK_SIZE-CPUINFO_sizeof-__PAGE_OFFSET),%esp
 
         /* Reset EFLAGS (subsumes CLI and CLD). */
 	pushl	$0
@@ -167,7 +169,7 @@ no_execute_disable:
         lidt    idt_descr
                 
         cmp     $(SECONDARY_CPU_FLAG),%ebx
-        je      init_secondary
+        je      start_secondary
 
         /* Call into main C routine. This should never return.*/
        	call	__start_xen
@@ -189,7 +191,7 @@ ignore_int:
 /*** STACK LOCATION ***/
         
 ENTRY(stack_start)
-        .long cpu0_stack + STACK_SIZE - __PAGE_OFFSET
+        .long cpu0_stack
         .long __HYPERVISOR_DS
         
 /*** DESCRIPTOR TABLES ***/
diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S
index d89b7bf51a..3ab012aad8 100644
--- a/xen/arch/x86/boot/x86_64.S
+++ b/xen/arch/x86/boot/x86_64.S
@@ -1,5 +1,6 @@
 #include <xen/config.h>
 #include <public/xen.h>
+#include <asm/asm_defns.h>
 #include <asm/desc.h>
 #include <asm/page.h>
 #include <asm/msr.h>
@@ -121,7 +122,8 @@ skip_boot_checks:
         mov     %rcx,%cr4
 
         mov     stack_start(%rip),%rsp
-        
+        or      $(STACK_SIZE-CPUINFO_sizeof),%rsp
+
         /* Reset EFLAGS (subsumes CLI and CLD). */
         pushq   $0
         popf
@@ -140,9 +142,9 @@ __high_start:
         mov     %ecx,%ss
 
         lidt    idt_descr(%rip)
-                
+
         cmp     $(SECONDARY_CPU_FLAG),%ebx
-        je      init_secondary
+        je      start_secondary
 
         /* Initialize BSS (no nasty surprises!) */
         lea     __bss_start(%rip),%rdi
@@ -219,7 +221,7 @@ idt:
         .quad   idt_table
 
 ENTRY(stack_start)
-        .quad   cpu0_stack + STACK_SIZE
+        .quad   cpu0_stack
 
 high_start:
         .quad   __high_start
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index f39a43c185..38fb25d16e 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -142,9 +142,7 @@ static void __init do_initcalls(void)
 
 static struct e820entry e820_raw[E820MAX];
 
-static multiboot_info_t *mbi;
-
-void __init start_of_day(void)
+void __init __start_xen(multiboot_info_t *mbi)
 {
     unsigned long vgdt, gdt_pfn;
     char *cmdline;
@@ -561,12 +559,6 @@ void __init start_of_day(void)
     startup_cpu_idle_loop();
 }
 
-void __init __start_xen(multiboot_info_t *__mbi)
-{
-    mbi = __mbi;
-    reset_stack_and_jump(start_of_day);
-}
-
 void arch_get_xen_caps(xen_capabilities_info_t info)
 {
     char *p = info;
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 96117b0727..30ca4864b2 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -429,7 +429,7 @@ static void construct_percpu_idt(unsigned int cpu)
 /*
  * Activate a secondary processor.
  */
-void __init start_secondary(void)
+void __init start_secondary(void *unused)
 {
 	unsigned int cpu = cpucount;
 
@@ -472,11 +472,6 @@ void __init start_secondary(void)
 	startup_cpu_idle_loop();
 }
 
-void __init init_secondary(void)
-{
-    reset_stack_and_jump(start_secondary);
-}
-
 extern struct {
 	void * esp;
 	unsigned short ss;
@@ -768,7 +763,6 @@ static int __init do_boot_cpu(int apicid)
 {
 	struct domain *idle;
 	struct vcpu *v;
-	void *stack;
 	unsigned long boot_error;
 	int timeout, cpu;
 	unsigned long start_eip;
@@ -791,15 +785,10 @@ static int __init do_boot_cpu(int apicid)
 	/* So we see what's up   */
 	printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip);
 
-	stack = alloc_xenheap_pages(STACK_ORDER);
-#if defined(__i386__)
-	stack_start.esp = (void *)__pa(stack) + STACK_SIZE;
-#elif defined(__x86_64__)
-	stack_start.esp = stack + STACK_SIZE;
-#endif
+	stack_start.esp = alloc_xenheap_pages(STACK_ORDER);
 
 	/* Debug build: detect stack overflow by setting up a guard page. */
-	memguard_guard_stack(stack);
+	memguard_guard_stack(stack_start.esp);
 
 	/*
 	 * This grunge runs the startup process for