From 15afc798fdf77f773564b68a80c7543f33b2a856 Mon Sep 17 00:00:00 2001
From: John Birrell <jb@FreeBSD.org>
Date: Tue, 9 Mar 2004 02:49:24 +0000
Subject: [PATCH] AMD's ELAN documentation says that you write to the SYS_RST
 register in the Memory Mapped Configuration Region (MMCR) to reset the CPU.
 If CPU_ELAN is set, try this first to reset the CPU before the traditional
 way.

Without this change, my Compulab board powers down on 'reset' instead
of rebooting.
---
 sys/i386/i386/vm_machdep.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c
index b09128d483c..7007e54909a 100644
--- a/sys/i386/i386/vm_machdep.c
+++ b/sys/i386/i386/vm_machdep.c
@@ -43,6 +43,7 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include "opt_cpu.h"
 #include "opt_isa.h"
 #include "opt_kstack_pages.h"
 #include "opt_npx.h"
@@ -77,6 +78,9 @@ __FBSDID("$FreeBSD$");
 #include <machine/pcb.h>
 #include <machine/pcb_ext.h>
 #include <machine/vm86.h>
+#ifdef	CPU_ELAN
+#include <machine/elan_mmcr.h>
+#endif
 
 #ifdef CPU_ELAN
 #include <machine/elan_mmcr.h>
@@ -559,6 +563,12 @@ cpu_reset_real()
 	}
 	outb(0xf0, 0x00);		/* Reset. */
 #else
+#ifdef	CPU_ELAN
+	if (elan_mmcr != NULL)
+		/* SYS_RST */
+		elan_mmcr->RESCFG = 1;
+#endif
+
 	/*
 	 * Attempt to do a CPU reset via the keyboard controller,
 	 * do not turn of the GateA20, as any machine that fails