diff -Npur dbf-sos-9_5/hwcore/cpu_context.c dbf-sos-9_5-modif/hwcore/cpu_context.c
--- dbf-sos-9_5/hwcore/cpu_context.c	2006-06-10 09:18:00.000000000 +0200
+++ dbf-sos-9_5-modif/hwcore/cpu_context.c	2006-06-12 18:22:41.000000000 +0200
@@ -24,6 +24,8 @@
 #include <drivers/x86_videomem.h>
 #include <hwcore/segment.h>
 #include <hwcore/gdt.h>
+#include <hwcore/paging.h>
+#include <hwcore/exception.h>
 #include <sos/uaccess.h>
 
 #include "cpu_context.h"
@@ -214,6 +216,8 @@ struct x86_tss {
 static struct x86_tss kernel_tss;
 static struct x86_tss double_fault_tss;
 
+extern unsigned int double_fault_alternate_stack;
+#define ALTERNATE_DOUBLE_FAULT_STACK_SIZE 512
 
 sos_ret_t sos_cpu_context_subsystem_setup()
 {
@@ -236,6 +240,17 @@ sos_ret_t sos_cpu_context_subsystem_setu
   kernel_tss.ss0 = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KDATA);
 
   double_fault_tss.ss0 = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KDATA);
+  double_fault_tss.esp0 = double_fault_alternate_stack + ALTERNATE_DOUBLE_FAULT_STACK_SIZE;
+  double_fault_tss.cr3 = sos_paging_get_current_PD_paddr();
+  double_fault_tss.eip = (sos_vaddr_t) sos_exception_get_routine(SOS_EXCEPT_DOUBLE_FAULT);
+  asm ("pushf ; popl %0"
+	: "=r" (double_fault_tss.eflags));
+  double_fault_tss.es = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KDATA);
+  double_fault_tss.cs = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KCODE);
+  double_fault_tss.ss = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KDATA);
+  double_fault_tss.ds = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KDATA);
+  double_fault_tss.fs = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KDATA);
+  double_fault_tss.gs = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KDATA);
 
   /* Register the double fault TSS into the GDT */
   sos_gdt_register_double_fault_tss((sos_vaddr_t) &double_fault_tss);
diff -Npur dbf-sos-9_5/hwcore/exception.c dbf-sos-9_5-modif/hwcore/exception.c
--- dbf-sos-9_5/hwcore/exception.c	2006-01-22 12:48:00.000000000 +0100
+++ dbf-sos-9_5-modif/hwcore/exception.c	2006-06-12 18:11:21.000000000 +0200
@@ -167,7 +167,7 @@ sos_exception_handler_t sos_exception_ge
 
   /* Double fault not supported */
   if (exception_number == SOS_EXCEPT_DOUBLE_FAULT)
-    return NULL;
+    return sos_exception_wrapper_array[SOS_EXCEPT_DOUBLE_FAULT];
   
   /* Expected to be atomic */
   return sos_exception_handler_array[exception_number];
diff -Npur dbf-sos-9_5/hwcore/exception_wrappers.S dbf-sos-9_5-modif/hwcore/exception_wrappers.S
--- dbf-sos-9_5/hwcore/exception_wrappers.S	2006-01-22 12:48:00.000000000 +0100
+++ dbf-sos-9_5-modif/hwcore/exception_wrappers.S	2006-06-12 18:20:00.000000000 +0200
@@ -30,6 +30,8 @@
    with exception.c */
 .globl sos_exception_wrapper_array
 
+.globl double_fault_alternate_stack
+
 /** Update the kernel TSS in case we are switching to a thread in user
 	mode in order to come back into the correct kernel stack */
 .extern sos_cpu_context_update_kernel_tss
diff -Npur dbf-sos-9_5/hwcore/idt.c dbf-sos-9_5-modif/hwcore/idt.c
--- dbf-sos-9_5/hwcore/idt.c	2006-06-10 09:31:00.000000000 +0200
+++ dbf-sos-9_5-modif/hwcore/idt.c	2006-06-12 17:45:08.000000000 +0200
@@ -82,7 +82,14 @@ sos_ret_t sos_idt_subsystem_setup()
 
       /* Setup an empty IDTE interrupt gate, see figure 5-2 in Intel
 	 x86 doc, vol 3 */
-      idte->seg_sel   = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KCODE);
+      if (i == 8)
+      {
+        idte->seg_sel   = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_DBL_FAULT_TSS);
+      }
+      else
+      {
+        idte->seg_sel   = SOS_BUILD_SEGMENT_REG_VALUE(0, FALSE, SOS_SEG_KCODE);
+      }
       idte->reserved  = 0;
       idte->flags     = 0;
       if(i == 8)               /* Double fault gate */
diff -Npur dbf-sos-9_5/sos/main.c dbf-sos-9_5-modif/sos/main.c
--- dbf-sos-9_5/sos/main.c	2006-06-10 10:03:00.000000000 +0200
+++ dbf-sos-9_5-modif/sos/main.c	2006-06-13 11:50:53.000000000 +0200
@@ -201,6 +201,7 @@ void Toto(void)
 	char Tab[] = "Message a afficher !";
 	I = ((I + 1) % 20);
 	sos_x86_videomem_printf(I, 0, SOS_X86_VIDEO_FG_YELLOW | SOS_X86_VIDEO_BG_BLUE, "Toto  %d %s ", I, Tab);
+	sos_thread_yield();
 	Toto();
 }