From 2412f2817dde1e398af6640f472882438f8c502b Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 27 Aug 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-08-27

---
 gnot/mmu.c |  7 +++++++
 pc/fns.h   |  2 +-
 pc/main.c  | 16 ++++++++--------
 pc/mmu.c   |  2 +-
 pc/trap.c  |  2 +-
 5 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/gnot/mmu.c b/gnot/mmu.c
index 7687323efbc3447318ce1ea17eb0e038aa2e3768..75067dfb42683c73f19fdb4c100cf420cca664bc 100644
--- a/gnot/mmu.c
+++ b/gnot/mmu.c
@@ -143,7 +143,9 @@ KMap*
 kmap(Page *pg)
 {
 	KMap *k;
+	int s;
 
+	s = splhi();
 	lock(&kmapalloc);
 	k = kmapalloc.free;
 	if(k == 0){
@@ -152,6 +154,7 @@ kmap(Page *pg)
 	}
 	kmapalloc.free = k->next;
 	unlock(&kmapalloc);
+	splx(s);
 
 	k->pa = pg->pa;
 	putkmmu(k->va, PPN(k->pa) | PTEVALID | PTEKERNEL);
@@ -161,13 +164,17 @@ kmap(Page *pg)
 void
 kunmap(KMap *k)
 {
+	int s;
+
 	k->pa = 0;
 	putkmmu(k->va, INVALIDPTE);
 
+	s = splhi();
 	lock(&kmapalloc);
 	k->next = kmapalloc.free;
 	kmapalloc.free = k;
 	unlock(&kmapalloc);
+	splx(s);
 }
 
 void
diff --git a/pc/fns.h b/pc/fns.h
index 5241c1e7490ba6b771bbf49045a985375492620b..40c8b0bd1eb95c19d8870359c26bd5ded3db8ab2 100644
--- a/pc/fns.h
+++ b/pc/fns.h
@@ -1,6 +1,6 @@
 #include "../port/portfns.h"
 
-void	a20enable(void);
+void	meminit(void);
 #define	clearmmucache()		/* 386 doesn't have one */
 void	clock(Ureg*);
 void	clockinit(void);
diff --git a/pc/main.c b/pc/main.c
index 5b0f87c3212ea7a9d1aaf87e5b50959936130759..b994647c7eaa7e40e0026ae359dbe967a309e71f 100644
--- a/pc/main.c
+++ b/pc/main.c
@@ -13,12 +13,12 @@ extern long edata;
 void
 main(void)
 {
-	a20enable();
+	meminit();
 	machinit();
 	confinit();
 	screeninit();
 	printinit();
-	print("%lud K bytes of physical memory\n", 1024 + conf.npage1*BY2PG/1024);
+	print("%ludK bytes of physical memory\n", (conf.base1 + conf.npage1*BY2PG)/1024);
 	mmuinit();
 	trapinit();
 	kbdinit();
@@ -174,14 +174,14 @@ confinit(void)
 			break;
 		x += 0x3141526;
 	}
-	conf.npage1 = (i-2)*1024/4;
-	conf.base1 = 1024*1024;
+	conf.base1 = 0x100000;
+	conf.npage1 = ((i-1)*1024*1024 - conf.base1)/BY2PG;
 
 	conf.npage = conf.npage0 + conf.npage1;
 	conf.maxialloc = 2*1024*1024;
 
 	mul = 1;
-	conf.nproc = 20 + 20*mul;
+	conf.nproc = 10 + 10*mul;
 	conf.npgrp = conf.nproc/2;
 	conf.nseg = conf.nproc*3;
 	conf.npagetab = (conf.nseg*14)/10;
@@ -198,7 +198,7 @@ confinit(void)
 	conf.nmntbuf = conf.nmntdev+3;
 	conf.nmnthdr = 2*conf.nmntdev;
 	conf.nsrv = 16*mul;			/* was 32 */
-	conf.nbitmap = 512*mul;
+	conf.nbitmap = 256*mul;
 	conf.nbitbyte = conf.nbitmap*1024*screenbits();
 	conf.nfont = 10*mul;
 	conf.nnoifc = 1;
@@ -296,9 +296,9 @@ enum
  *  enable address bit 20
  */
 void
-a20enable(void)
+meminit(void)
 {
-	outb(Head, A20ena);
+	outb(Head, A20ena);		/* enable memory address bit 20 */
 }
 
 /*
diff --git a/pc/mmu.c b/pc/mmu.c
index 208fc5212d0e90accb6120a3a7bb7c6a47200d04..a770f37cb8ad8acef09ea6f5754e1d295feb9ad3 100644
--- a/pc/mmu.c
+++ b/pc/mmu.c
@@ -124,7 +124,7 @@ mmuinit(void)
 	 */
 
 	/*  allocate and fill low level page tables for kernel mem */
-	npage = (1024*1024)/BY2PG + conf.npage1;
+	npage = conf.base1/BY2PG + conf.npage1;
 	nbytes = PGROUND(npage*BY2WD);		/* words of page map */
 	nkpt = nbytes/BY2PG;			/* pages of page map */
 	kpt = ialloc(nbytes, 1);
diff --git a/pc/trap.c b/pc/trap.c
index 6e0edc742f8f911dca7e5df684fee1f52ae2ab12..67a5ba150d50b871b14a6a5301154e76f8466792 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -174,7 +174,7 @@ trap(Ureg *ur)
 
 	v = ur->trap;
 	if(v>=256 || ivec[v] == 0){
-		print("bad trap type %d %lux %lux %lux\n", v, ur->pc, int0mask, int1mask);
+		panic("bad trap type %d %lux %lux %lux\n", v, ur->pc, int0mask, int1mask);
 		return;
 	}