diff --git a/src/cpu/amd/agesa/cache_as_ram.inc b/src/cpu/amd/agesa/cache_as_ram.inc
index a8dbee8573..b19f03b0a6 100644
--- a/src/cpu/amd/agesa/cache_as_ram.inc
+++ b/src/cpu/amd/agesa/cache_as_ram.inc
@@ -64,9 +64,67 @@ cache_as_ram_setup:
   cvtsi2sd  %ebx, %xmm1
 
   post_code(0xa1)
-  AMD_ENABLE_STACK
 
-  post_code(0xa1)
+#ifdef __x86_64__
+  /* switch to 64 bit long mode */
+  .intel_syntax noprefix
+
+  mov     ecx, esi
+  add     ecx, 0 # core number
+  xor     eax, eax
+  lea     edi, [ecx+0x1000+0x23]
+  mov     dword ptr [ecx+0], edi
+  mov     dword ptr [ecx+4], eax
+
+  lea     edi, [ecx+0x1000]
+  mov     dword ptr [edi+0x00], 0x000000e3
+  mov     dword ptr [edi+0x04], eax
+  mov     dword ptr [edi+0x08], 0x400000e3
+  mov     dword ptr [edi+0x0c], eax
+  mov     dword ptr [edi+0x10], 0x800000e3
+  mov     dword ptr [edi+0x14], eax
+  mov     dword ptr [edi+0x18], 0xc00000e3
+  mov     dword ptr [edi+0x1c], eax
+
+  # load rom based identity mapped page tables
+  mov     eax, ecx
+  mov     cr3,eax
+
+  # enable PAE
+  mov     eax, cr4
+  bts     eax, 5
+  mov     cr4, eax
+
+  # enable long mode
+  mov     ecx, 0xC0000080
+  rdmsr
+  bts     eax, 8
+  wrmsr
+
+  # enable paging
+  mov     eax, cr0
+  bts     eax, 31
+  mov     cr0, eax
+
+  # use call far to switch to 64-bit code segment
+  jmp 0x18,.+7
+
+  /* Pass the BIST result */
+  cvtsd2si        esi, xmm1
+
+  /* Pass the cpu_init_detected */
+  cvtsd2si        edi, xmm0
+
+  /* align the stack */
+  and     esp, 0xFFFFFFF0
+
+  .code64
+  call    cache_as_ram_main
+  .code32
+
+  .att_syntax prefix
+#else
+  AMD_ENABLE_STACK
 
   /* Restore the BIST result */
   cvtsd2si  %xmm0, %edx
@@ -77,6 +135,7 @@ cache_as_ram_setup:
   pushl %ebx  /* init detected */
   pushl %edx  /* bist */
   call  cache_as_ram_main
+#endif
 
   /* Should never see this postcode */
   post_code(0xaf)
@@ -108,3 +167,6 @@ disable_cache_as_ram:
   ret
 
 cache_as_ram_setup_out:
+#ifdef __x86_64__
+.code64
+#endif
diff --git a/src/cpu/amd/agesa/s3_resume.c b/src/cpu/amd/agesa/s3_resume.c
index 5e07d7a405..98671f47d5 100644
--- a/src/cpu/amd/agesa/s3_resume.c
+++ b/src/cpu/amd/agesa/s3_resume.c
@@ -56,10 +56,17 @@ static void move_stack_high_mem(void)
 	memcpy(high_stack, (void *)BSP_STACK_BASE_ADDR, HIGH_ROMSTAGE_STACK_SIZE);
 
 	/* TODO: We only switch stack on BSP. */
+#ifdef __x86_64__
+	__asm__
+	    volatile ("add	%0, %%rsp; add %0, %%rbp; invd"::"g"
+		      (high_stack - BSP_STACK_BASE_ADDR)
+		      :);
+#else
 	__asm__
 	    volatile ("add	%0, %%esp; add %0, %%ebp; invd"::"g"
 		      (high_stack - BSP_STACK_BASE_ADDR)
 		      :);
+#endif
 }
 
 static void set_resume_cache(void)