From b7acd877ae1c91c02f5e78a6843ce3e01257dee8 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 30 Apr 2002 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2002-04-30

---
 bitsy/fns.h    |  2 ++
 bitsy/l.s      | 25 ++++++++++++++++++++++++-
 bitsy/trap.c   |  9 +++++++--
 pc/devvga.c    |  8 ++++----
 pc/mmu.c       |  1 +
 port/devproc.c |  3 +++
 6 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/bitsy/fns.h b/bitsy/fns.h
index 65fbff23b59866e7541b9003b5c2505e7281f42f..6fe8dd2f5668fe5bf9c0fb9a4f47a073f0c41e4a 100644
--- a/bitsy/fns.h
+++ b/bitsy/fns.h
@@ -43,6 +43,8 @@ ulong	getsp(void);
 void	gpiointrenable(ulong, int, void (*)(Ureg*, void*), void*, char*);
 void	h3650uartsetup(void);
 int	havetimer(void);
+void	_hibernate(void);
+void	(*hibernate)(void);
 void	icacheinvalidate(void);
 void	idle(void);
 void	idlehands(void);
diff --git a/bitsy/l.s b/bitsy/l.s
index a7516c9bb974697fa5cae749ba791580567b1922..8ab29d04cf8c907c46c3cd01cb470cb740629f5c 100644
--- a/bitsy/l.s
+++ b/bitsy/l.s
@@ -722,15 +722,38 @@ l14:	SUB		$1,R0
 	MOVW	0x2c(R3),R2
 	AND		$(~0x00030003),R2
 	MOVW	R2,0x2c(R3)
-	MOVW	R0,R0			/* filler */
 
+	MOVW	R0,R0
+	MOVW	R0,R0
+	MOVW	R0,R0
+	MOVW	R0,R0
+	MOVW	R0,R0
+	MOVW	R0,R0
+	MOVW	R0,R0
+	MOVW	R0,R0
+	MOVW	R0,R0
+	/* align this on a cache-line boundary */
 	MOVW	$1,R2
 	MOVW	R4,0x1c(R3)
 	MOVW	R6,0x1c(R3)
 	MOVW	R12,0x0(R3)
 	MOVW	R11,0x1c(R3)
 	MOVW	R2,0x0(R5)
+xlloop:
+	B		xlloop			/* loop waiting for sleep */
 
+/* The first instruction of this function needs to be on a cache-line
+ * boundary; to make this happen, it will be copied (in trap.c).
+ *
+ * Hibernate puts the machine into hibernation.
+ */
+TEXT _hibernate(SB), $-4
+	MOVW	$1,R2
+	MOVW	R4,0x1c(R3)
+	MOVW	R6,0x1c(R3)
+	MOVW	R12,0x0(R3)
+	MOVW	R11,0x1c(R3)
+	MOVW	R2,0x0(R5)
 slloop:
 	B		slloop			/* loop waiting for sleep */
 
diff --git a/bitsy/trap.c b/bitsy/trap.c
index 126df3fd0c481e1530ea8a0975acca629ab12799..3602ca91032f8b9cc37c5505372f5be64aaf6038 100644
--- a/bitsy/trap.c
+++ b/bitsy/trap.c
@@ -31,9 +31,10 @@ typedef struct Vpage0 {
 Vpage0 *vpage0;
 
 /*
- *  An cached line for the doze code
+ *  A cached line for the doze and hibernate code
  */
 void (*doze)(void);
+void (*hibernate)(void);
 
 static void	irq(Ureg*);
 static void	gpiointr(Ureg*, void*);
@@ -65,9 +66,13 @@ trapinit(void)
 	memmove(vpage0->vectors, vectors, sizeof(vpage0->vectors));
 	memmove(vpage0->vtable, vtable, sizeof(vpage0->vtable));
 
-	/* relocate the doze routine to a cache line boundary in cached mem */
+	/* relocate the doze and hibernate routines
+	 * to a cache line boundary in cached mem
+	 */
 	doze = xspanalloc(12*sizeof(long), 16, 0);
 	memmove(doze, _doze, 12*sizeof(long));
+	hibernate = xspanalloc(8*sizeof(long), 16, 0);
+	memmove(hibernate, _hibernate, 8*sizeof(long));
 	wbflush();
 
 	/* use exception vectors at 0xFFFF0000 */
diff --git a/pc/devvga.c b/pc/devvga.c
index 13a6f8473659bf63b0b7b622b313fd84df777c38..765eb83d673251e961c20ce54f8c258be5b614fc 100644
--- a/pc/devvga.c
+++ b/pc/devvga.c
@@ -97,7 +97,7 @@ vgaopen(Chan* c, int omode)
 
 	scr = &vgascreen[0];
 	if ((ulong)c->qid.path == Qvgaovlctl) {
-		if (scr->dev->ovlctl)
+		if (scr->dev && scr->dev->ovlctl)
 			scr->dev->ovlctl(scr, c, openctl, strlen(openctl));
 		else 
 			error(Enonexist);
@@ -113,7 +113,7 @@ vgaclose(Chan* c)
 
 	scr = &vgascreen[0];
 	if((ulong)c->qid.path == Qvgaovlctl)
-		if(scr->dev->ovlctl){
+		if(scr->dev && scr->dev->ovlctl){
 			if(waserror()){
 				print("ovlctl error: %s\n", up->errstr);
 				return;
@@ -418,7 +418,7 @@ vgawrite(Chan* c, void* a, long n, vlong off)
 
 	case Qvgaovl:
 		scr = &vgascreen[0];
-		if (scr->dev->ovlwrite == nil) {
+		if (scr->dev == nil || scr->dev->ovlwrite == nil) {
 			error(Enooverlay);
 			break;
 		}
@@ -426,7 +426,7 @@ vgawrite(Chan* c, void* a, long n, vlong off)
 
 	case Qvgaovlctl:
 		scr = &vgascreen[0];
-		if (scr->dev->ovlctl == nil) {
+		if (scr->dev == nil || scr->dev->ovlctl == nil) {
 			error(Enooverlay);
 			break;
 		}
diff --git a/pc/mmu.c b/pc/mmu.c
index 3e7080e8a9152181e7a33dd91c465195b69e9e95..4a2a0ed1f8c59b324bc24c228a63918c51967a75 100644
--- a/pc/mmu.c
+++ b/pc/mmu.c
@@ -56,6 +56,7 @@ memglobal(void)
 	int i, j;
 	ulong *pde, *pte;
 
+return;
 	/* only need to do this once, on bootstrap processor */
 	if(m->machno != 0)
 		return;
diff --git a/port/devproc.c b/port/devproc.c
index a0e8e32b20a1c8ef6d0148e6da9aa00448e262ec..d0fedbdaf1a453270a766fa9e915abe13af23a76 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -556,6 +556,9 @@ procread(Chan *c, void *va, long n, vlong off)
 		|| (offset >= USTKTOP-USTKSIZE && offset < USTKTOP))
 			return procctlmemio(p, offset, n, va, 1);
 
+		if(!iseve())
+			error(Eperm);
+
 		/* validate kernel addresses */
 		if(offset < (ulong)end) {
 			if(offset+n > (ulong)end)