From 6e8dc5bc374ed6ea4096b1504e5d50aa4cbdc43a Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sat, 9 Apr 1994 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1994-04-09

---
 pc/devvga.c    |  2 ++
 pc/l.s         | 51 +++++++++++++++++++++++++++++++++++++++++++++++---
 port/devproc.c |  2 +-
 3 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/pc/devvga.c b/pc/devvga.c
index ac0c2b266ee8342c2f743d3159799a17bc54ce46..4243ad5f2eb9f88f2a6069990e5f88a68bc9c0c3 100644
--- a/pc/devvga.c
+++ b/pc/devvga.c
@@ -627,6 +627,8 @@ screenupdate(void)
 		break;
 	case 3:
 		f = memmove;
+		r.min.x &= ~3;
+		r.max.x = ROUND(r.max.x, 4);
 		len = r.max.x - r.min.x;
 		break;
 	default:
diff --git a/pc/l.s b/pc/l.s
index 5d234639623136e63a26aa6f017c6372bca550e2..4d59232201ec9257eb47301e78cbf7cfa8f0fa3d 100644
--- a/pc/l.s
+++ b/pc/l.s
@@ -567,22 +567,29 @@ TEXT	idle(SB),$0
 	RET
 
 /*
- *  return cpu type (what is a pentium?)
+ *  return cpu type (586 == pentium or better)
  */
 TEXT	x86(SB),$0
 
 	PUSHFL
 	MOVL	0(SP),AX
-	ORL	$0x40000,AX
+	ORL	$0x240000,AX
 	PUSHL	AX
 	POPFL
 	PUSHFL
-	POPL	AX
+	MOVL	0(SP),AX
 	ANDL	$0x40000,AX
 	JZ	is386
+	POPL	AX
+	ANDL	$0x200000,AX
+	JZ	is486
+	MOVL	$586,AX
+	JMP	done
+is486
 	MOVL	$486,AX
 	JMP	done
 is386:
+	POPL	AX
 	MOVL	$386,AX
 done:
 	POPFL
@@ -818,3 +825,41 @@ dsploop:
 
 dspout:
 	RET
+
+
+	TEXT	damove(SB), $0
+
+	MOVL	p1+0(FP), DI
+	MOVL	p2+4(FP), SI
+	MOVL	n+8(FP), BX
+	CLD
+/*
+ * less than a word, just copy bytes
+ */
+	CMPL	BX, $4
+	JLS	bybyte
+/*
+ * copy bytes till dest is word alligned
+ */
+	MOVL	DI, DX
+	ANDL	$3, DX
+	JEQ	byword
+	MOVL	$4, CX
+	SUBL	DX, CX
+	SUBL	CX, BX
+	REP;	MOVSB
+/*
+ * copy whole longs
+ */
+byword:
+	MOVL	BX, CX
+	SHRL	$2, CX
+	REP;	MOVSL
+/*
+ * copy the rest, by bytes
+ */
+	ANDL	$3, BX
+bybyte:
+	MOVL	BX, CX
+	REP;	MOVSB
+	RET
diff --git a/port/devproc.c b/port/devproc.c
index eb244a50ad0baf23b1f7384be91a858596671c73..b4dd53f20ace441a6837c825ba9f2ca4b1fbf529 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -775,7 +775,7 @@ procctlmemio(Proc *p, ulong offset, int n, void *va, int read)
 		if(offset+n >= s->top)
 			n = s->top-offset;
 
-		if((s->type&SG_TYPE) == SG_TEXT)
+		if(!read && (s->type&SG_TYPE) == SG_TEXT)
 			s = txt2data(p, s);
 
 		s->steal++;