From b4332373ab225bb7ee66a6683e3afa9630265a6a Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 22 Dec 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-12-22

---
 gnot/bbmalloc.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++
 gnot/screen.c   |  2 +-
 gnot/screen.h   |  2 +-
 power/main.c    |  3 +--
 ss/main.c       |  2 +-
 5 files changed, 75 insertions(+), 5 deletions(-)
 create mode 100644 gnot/bbmalloc.c

diff --git a/gnot/bbmalloc.c b/gnot/bbmalloc.c
new file mode 100644
index 0000000000000000000000000000000000000000..30f1edb78c60bf8a6b928554a959d8c6992e5b0b
--- /dev/null
+++ b/gnot/bbmalloc.c
@@ -0,0 +1,71 @@
+#include	"u.h"
+#include	"lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"io.h"
+
+/*
+ * Allocate memory for use in kernel bitblts.
+ * The allocated memory must have a flushed instruction
+ * cache, and the data cache must be flushed by bbdflush().
+ * To avoid the need for frequent cache flushes, the memory
+ * is allocated out of an arena, and the i-cache is only
+ * flushed when it has to be reused.  By returning an
+ * address in non-cached space, the need for flushing the
+ * d-cache is avoided.
+ *
+ * This code will have to be interlocked if we ever get
+ * a multiprocessor with a bitmapped display.
+ */
+
+/* a 0->3 bitblt can take 800 longs */
+enum {
+	narena=2,	/* put interrupt time stuff in separate arena */
+	nbbarena=4096	/* number of words in an arena */
+};
+
+static ulong	bbarena[narena][nbbarena];
+static ulong	*bbcur[narena] = {&bbarena[0][0], &bbarena[1][0]};
+static ulong	*bblast[narena] = {0, 0};
+
+#define INTLEVEL(v)	((v)&0x700)
+void *
+bbmalloc(int nbytes)
+{
+	int nw, a;
+	int s;
+	ulong *ans;
+
+	nw = nbytes/sizeof(long);
+	s = splhi();
+	a = INTLEVEL(s)? 1 : 0;
+	if(bbcur[a] + nw > &bbarena[a][nbbarena])
+		ans = bbarena[a];
+	else
+		ans = bbcur[a];
+	bbcur[a] = ans + nw;
+	splx(s);
+	bblast[a] = ans;
+	return ans;
+}
+
+void
+bbfree(void *p, int n)
+{
+	ulong *up;
+	int a, s;
+
+	s = splhi();
+	a = INTLEVEL(s)? 1 : 0;
+	if(p == bblast[a])
+		bbcur[a] = (ulong *)(((char *)bblast[a]) + n);
+	splx(s);
+}
+
+void *
+bbdflush(void *p, int n)
+{
+	flushcpucache();
+	return (void *)(((ulong)p));
+}
diff --git a/gnot/screen.c b/gnot/screen.c
index c6c79cf28f7fd6ec0b3000287f6fa1573eaec91f..99f738555a8ac5c9124dcabd5939e319c399d8f0 100644
--- a/gnot/screen.c
+++ b/gnot/screen.c
@@ -74,7 +74,7 @@ screenputc(int c)
 			screenputc('\n');
 		buf[0] = c&0x7F;
 		buf[1] = 0;
-		out.pos = gbitbltstring(&gscreen, out.pos, defont, buf, S);
+		out.pos = gstring(&gscreen, out.pos, defont, buf, S);
 	}
 }
 
diff --git a/gnot/screen.h b/gnot/screen.h
index 4fd92d336c661a0dd8759b7da095c92e15da3dc9..45d3e2938c0e831ba69f83aa307f1717bfdb5102 100644
--- a/gnot/screen.h
+++ b/gnot/screen.h
@@ -32,4 +32,4 @@ extern void		mouseupdate(int);
  * kernel mustn't use balu; user (/dev/bitblt) can
  */
 #define kbitblt 	gbitblt
-#define	ubitblt		balubitblt
+#define	ubitblt		gbitblt
diff --git a/power/main.c b/power/main.c
index 4803fa206cd96ffbecdf701b25303d27e3723769..6acba6103c0aab7e9d5e87832aaf827bab07582d 100644
--- a/power/main.c
+++ b/power/main.c
@@ -222,7 +222,6 @@ init0(void)
 	 */
 	u->slash = (*devtab[0].attach)(0);
 	u->dot = clone(u->slash, 0);
-
 	chandevinit();
 
 	if(!waserror()){
@@ -265,7 +264,7 @@ userinit(void)
 	 */
 	p->sched.pc = (ulong)init0;
 	p->sched.sp = USERADDR+BY2PG-(1+MAXSYSARG)*BY2WD;
-	p->upage = newpage(0, 0, USERADDR|(p->pid&0xFFFF));
+	p->upage = newpage(1, 0, USERADDR|(p->pid&0xFFFF));
 
 	/*
 	 * User
diff --git a/ss/main.c b/ss/main.c
index 20cb47c9aa841e9de4cb933422131c97f344fff3..8dc04bb461d72af6206641f6028e13c1530dacf3 100644
--- a/ss/main.c
+++ b/ss/main.c
@@ -143,7 +143,7 @@ userinit(void)
 	 */
 	p->sched.pc = (((ulong)init0) - 8);	/* 8 because of RETURN in gotolabel */
 	p->sched.sp = USERADDR+BY2PG-(1+MAXSYSARG)*BY2WD;
-	p->upage = newpage(0, 0, USERADDR|(p->pid&0xFFFF));
+	p->upage = newpage(1, 0, USERADDR|(p->pid&0xFFFF));
 
 	/*
 	 * User