From 60e799f7b4479584c1baf7dc36dbf140663706e9 Mon Sep 17 00:00:00 2001
From: Adrian-Ken Rueegsegger <ken@codelabs.ch>
Date: Wed, 18 Feb 2015 00:30:14 +0100
Subject: [PATCH] hw_x86_64: Set segment registers prior to mode transition

The registers for the ds, es, fs and gs segments are hardcoded to GDT
index 4 with requested privilege level set to 3.
---
 repos/base-hw/src/core/spec/x86_64/mode_transition.s | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/repos/base-hw/src/core/spec/x86_64/mode_transition.s b/repos/base-hw/src/core/spec/x86_64/mode_transition.s
index 3bbc0e238..1bfbdea40 100644
--- a/repos/base-hw/src/core/spec/x86_64/mode_transition.s
+++ b/repos/base-hw/src/core/spec/x86_64/mode_transition.s
@@ -90,6 +90,13 @@
 	pushq $0x1b
 	pushq (%rax)
 
+	/* Restore segment registers */
+	mov $0x23, %rbx
+	mov %rbx, %ds
+	mov %rbx, %es
+	mov %rbx, %fs
+	mov %rbx, %gs
+
 	1: jmp 1b
 
 	/* end of the mode transition code */