diff -r ac48ec8ffd86 platform/pc99/pistachio/src/reboot.cc
--- a/platform/pc99/pistachio/src/reboot.cc	Tue Aug 03 13:10:36 2010 +0200
+++ b/platform/pc99/pistachio/src/reboot.cc	Tue Oct 05 15:30:32 2010 +0200
@@ -58,7 +58,9 @@
 /*
  * Description:   PC99 reset
  */
+
 #include <kernel/arch/platform.h>
+#include <kernel/arch/ioport.h>
 
 /*
  * Reboot the box
@@ -66,6 +68,39 @@
 
 void Platform::reboot(void)
 {
+  asm volatile ("cli  \n" :);
 
-    for (;;);
+  /* i8042: store the next byte at port 0x60 as command byte */
+  while (in_u8(0x64) & 0x2) ;
+  out_u8(0x64, 0x60);
+
+  /* i8042 command byte (PS/2-compatible mode):
+        b0=0 ... no IRQ 1 is generated when data available in
+                 input buffer
+        b1=0 ... no IRQ 1 is generated when mouse data available
+                 in input buffer
+        b2=1 ... set SYS flag in status register -- tells POST
+                 to perform "warm boot" tests/initiailization
+        b3=0 ... reserved
+        b4=0 ... keyboard interface enabled
+        b5=0 ... auxillary PS/2 device (mouse) interface
+                 enabled
+        b6=0 ... translation disabled -- data appears at
+                 input buffer exactly as read from keyboard
+        b7=0 ... reserved
+   */
+   while (in_u8(0x64) & 0x2) ;
+   out_u8(0x60, 0x4);
+
+   /* i8042: pulse output port with 1110b
+         b0=0 ... reset computer
+         b1=1 ... set gate A20
+         b2=1 ... pull mouse data low
+         b3=1 ... pull mouse clock low
+   */
+   while (in_u8(0x64) & 0x2) ;
+   out_u8(0x64, 0xfe);
+
+   for (;;)
+       asm volatile ("hlt  \n" :);
 }