1 files changed, 5 insertions, 3 deletions

diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S
index 2e559233725a..fa6bed1fac14 100644
--- a/arch/x86/boot/pmjump.S
+++ b/arch/x86/boot/pmjump.S
@@ -28,17 +28,19 @@
  * void protected_mode_jump(u32 entrypoint, u32 bootparams);
  */
 protected_mode_jump:
-        xorl    %ebx, %ebx              # Flag to indicate this is a boot
         movl    %edx, %esi              # Pointer to boot_params table
         movl    %eax, 2f                # Patch ljmpl instruction
-        jmp     1f                      # Short jump to flush instruction q.
 
-1:
         movw    $__BOOT_DS, %cx
+        xorl    %ebx, %ebx              # Per the 32-bit boot protocol
+        xorl    %ebp, %ebp              # Per the 32-bit boot protocol
+        xorl    %edi, %edi              # Per the 32-bit boot protocol
 
         movl    %cr0, %edx
         orb     $1, %dl                 # Protected mode (PE) bit
         movl    %edx, %cr0
+        jmp     1f                      # Short jump to serialize on 386/486
+1:
 
         movw    %cx, %ds
         movw    %cx, %es