From 27806bee8a156f30e9634a8e8356ffcb85e89f1e Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Fri, 1 Oct 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-10-01

---
 carrera/kbd.c    | 13 +++++++++++--
 carrera/screen.c |  2 +-
 carrera/trap.c   |  3 +++
 port/segment.c   | 37 +++++++++++++++++++++++--------------
 4 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/carrera/kbd.c b/carrera/kbd.c
index c471ea6bfe88c1ee30131c9dca114e825ab29da9..e60664d346963e6030ab8ca8ebbe7f4bdba54fc0 100644
--- a/carrera/kbd.c
+++ b/carrera/kbd.c
@@ -166,9 +166,8 @@ kbdwait(void)
 	int tries;
 
 	for(tries = 0; tries < 2000; tries++){
-		if(KBDCTL & Sobf){
+		if(KBDCTL & Sobf)
 			return 1;
-		}
 		kdbdly(1);
 	}
 	return 0;
@@ -185,6 +184,16 @@ kbdackwait(void)
 	return 0;
 }
 
+void
+mouseintr(void)
+{
+	uchar code;
+
+	kbdwait();
+	code = KBDDAT;
+	print("mouse intr %d\n", code);
+}
+
 int
 kbdintr(void)
 {
diff --git a/carrera/screen.c b/carrera/screen.c
index 5101ad5e82a87cf4d49d1425c2940952c416bb0d..30d4d3e624a25073decc057d127c32e9bc5e3ebe 100644
--- a/carrera/screen.c
+++ b/carrera/screen.c
@@ -270,7 +270,7 @@ screenputc(char *buf)
 		cursor.x += pos*w;
 		break;
 	case '\b':
-		if(cursor.x-w >= 0)
+		if(cursor.x-w >= window.min.x)
 			cursor.x -= w;
 		break;
 	default:
diff --git a/carrera/trap.c b/carrera/trap.c
index d6a2bcb23131c318b6df9a8738068d0d429267aa..020dd11867751671ebc677ef230392ba2d967457 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -305,6 +305,9 @@ intr(Ureg *ur)
 			case 0x1C:
 				kbdintr();
 				break;
+			case 0x20:
+				mouseintr();
+				break;
 			}
 		}
 		cause &= ~INTR3;
diff --git a/port/segment.c b/port/segment.c
index 2de99627f7208b9f88ba61c32009a375854200f8..7875e2e092dd7e89eec4c782c83440bf5e1e8298 100644
--- a/port/segment.c
+++ b/port/segment.c
@@ -464,12 +464,9 @@ pteflush(Pte *pte, int s, int e)
 	int i;
 	Page *p;
 
-	if(pte == 0)
-		return;
-
 	for(i = s; i < e; i++) {
 		p = pte->pages[i];
-		if(p != 0)
+		if(pagedout(p) == 0)
 			memset(p->cachectl, PG_TXTFLUSH, sizeof(p->cachectl));
 	}
 }
@@ -478,7 +475,8 @@ long
 syssegflush(ulong *arg)
 {
 	Segment *s;
-	ulong addr, ua, l;
+	ulong addr, l;
+	Pte *pte;
 	int chunk, ps, pe, len;
 
 	addr = arg[0];
@@ -490,23 +488,34 @@ syssegflush(ulong *arg)
 			error(Ebadarg);
 
 		s->flushme = 1;
-
+	more:
 		l = len;
 		if(addr+l > s->top)
 			l = s->top - addr;
-		ua = addr-s->base;
-		ps = ua&(PTEMAPMEM-1);
-		pe = (ua+l)&(PTEMAPMEM-1);
-		pe = (pe+BY2PG-1)&~(BY2PG-1);
-		if(pe > PTEMAPMEM)
-			pe = PTEMAPMEM;
-	
-		pteflush(s->map[ua/PTEMAPMEM], ps/BY2PG, pe/BY2PG);
+
+		ps = addr-s->base;
+		pte = s->map[ps/PTEMAPMEM];
+		ps &= PTEMAPMEM-1;
+		pe = PTEMAPMEM;
+		if(pe-ps > l){
+			pe = ps + l;
+			pe = (pe+BY2PG-1)&~(BY2PG-1);
+		}
+		if(pe == ps) {
+			qunlock(&s->lk);
+			error(Ebadarg);
+		}
+
+		if(pte)
+			pteflush(pte, ps/BY2PG, pe/BY2PG);
 
 		chunk = pe-ps;
 		len -= chunk;
 		addr += chunk;
 
+		if(len > 0 && addr < s->top)
+			goto more;
+
 		qunlock(&s->lk);
 	}
 	flushmmu();