Fix trap frame layout.

cpu/isr.h

@@ -28,8 +28,8 @@ enum {
  * - `push eax` whose lower 16-bits contain DS
  */
 typedef struct {
-    uint32_t ds; /* Data segment selector */
     uint32_t edi, esi, ebp, esp, ebx, edx, ecx, eax; /* Pushed by pusha. */
+    uint32_t gs, fs, es, ds; /* Data segment selector */
     uint32_t int_no, err_code; /* Interrupt number and error code (if applicable) */
     uint32_t eip, cs, eflags, useresp, ss; /* Pushed by the processor automatically */
 } registers_t;

cpu/vectors.S

@@ -6,8 +6,8 @@ alltraps:
     pushl %gs
     pushal
 
-    mov $10, %ax
-    mov %ax, %ds
+    //mov $10, %ax
+    //mov %ax, %ds
     
     # Call trap(tf), where tf=%esp
     pushl %esp