From 9067c13a4d4d2b9ce16749d68e592a01c1e503c4 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Fri, 17 Dec 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-12-17

---
 carrera/dat.h      |  1 -
 carrera/devether.c | 17 +++++++----
 carrera/l.s        | 12 +++++++-
 carrera/main.c     | 70 ++++++++++++++++++++++++++++++++++++----------
 carrera/trap.c     |  1 -
 pc/devvga.c        |  8 +++---
 port/chan.c        |  9 ++++++
 port/devcons.c     |  6 ++++
 8 files changed, 97 insertions(+), 27 deletions(-)

diff --git a/carrera/dat.h b/carrera/dat.h
index 19b25371d02bfcab1e8c217af37e55c228948da1..af09dce8180c41bd57c1c6c3ee5763816ecdeb2c 100644
--- a/carrera/dat.h
+++ b/carrera/dat.h
@@ -139,7 +139,6 @@ struct KMap
 	KMap*	next;
 	KMap*	konmach[MAXMACH];
 	Page*	pg;
-	char	inuse;			/* number of procs using kmap */
 };
 
 #define	VA(k)		((k)->virt)
diff --git a/carrera/devether.c b/carrera/devether.c
index 500d76292bee6bdf56f16e593d23c4aaa7936f5f..81c774f8c5a2c87fdc732fd7492eb5c2117754ee 100644
--- a/carrera/devether.c
+++ b/carrera/devether.c
@@ -15,8 +15,8 @@
 
 #define SONICADDR	((Sonic*)Sonicbase)
 
-#define RD(rn)		(delay(1), *(ulong*)((ulong)&SONICADDR->rn^4))
-#define WR(rn, v)	(delay(1), *(ulong*)((ulong)&SONICADDR->rn^4) = (v))
+#define RD(rn)		(delay(0), *(ulong*)((ulong)&SONICADDR->rn^4))
+#define WR(rn, v)	(delay(0), *(ulong*)((ulong)&SONICADDR->rn^4) = (v))
 #define ISquad(s)	if((ulong)s & 0x7) panic("sonic: Quad alignment");
 
 typedef struct Pbuf Pbuf;
@@ -74,8 +74,8 @@ typedef struct
 
 enum
 {
-	Nrb		= 16,		/* receive buffers */
-	Ntb		= 16,		/* transmit buffers */
+	Nrb		= 8,		/* receive buffers */
+	Ntb		= 8,		/* transmit buffers */
 };
 
 enum
@@ -530,8 +530,10 @@ etherintr(void)
 			status &= ~Hbl;
 		}
 		if(status & Br){
-			print("sonic: bus retry occurred\n");
+			WR(cr, 0);
+			iprint("sonic: bus retry occurred\n");
 			status &= ~Br;
+			for(;;);
 		}
 	
 		if(status & AllIntr)
@@ -560,9 +562,10 @@ static void
 initbufs(Ether *c)
 {
 	int i;
-	uchar *mem;
+	uchar *mem, *base;
 
 	mem = xspanalloc(64*1024, BY2PG, 0);
+	base = mem;
 	mem = CACHELINE(uchar, mem);
 
 	/*
@@ -595,6 +598,8 @@ initbufs(Ether *c)
 		mem += sizeof(Pbuf);
 		mem = QUAD(uchar, mem);
 	}
+	if(mem >= base+64*1024)
+		panic("sonic init");
 }
 
 void
diff --git a/carrera/l.s b/carrera/l.s
index eec3b94c7db726e75e256270d4fcb53488d30623..2cf998d4b5896973dd5e941959f8cc9b63943a17 100644
--- a/carrera/l.s
+++ b/carrera/l.s
@@ -12,7 +12,17 @@
 
 #define	CONST(x,r)	MOVW $((x)&0xffff0000), r; OR  $((x)&0xffff), r
 
-#define	RDBGSV		CONST(0x80020000, R26); MOVW R29, 0(R26); MOVW M(EPC), R27; MOVW R27, 4(R26); MOVW R31, 8(R26)
+#define	RDBGSV		CONST(0x80020000, R26);	\
+			MOVW R29, 0(R26); \
+			MOVW M(EPC), R27; \
+			MOVW R27, 4(R26); \
+			MOVW R31, 8(R26); \
+			MOVW M(CAUSE), R27; \
+			MOVW R27, 12(R26); \
+			MOVW M(STATUS), R27; \
+			MOVW R27, 16(R26); \
+			MOVW M(BADVADDR), R27; \
+			MOVW R27, 20(R26)
 
 /*
  *  R4000 instructions
diff --git a/carrera/main.c b/carrera/main.c
index 6a3346c52b13e054afe60127b1a4ec480e224930..91f8c35856703d476854310831cec4eb5d5f5435 100644
--- a/carrera/main.c
+++ b/carrera/main.c
@@ -37,8 +37,9 @@ extern	ulong	rdbglen;
 void
 main(void)
 {
-	tlbinit();		/* Very early to establish IO mappings */
-	ioinit(1);
+	rdbginit();
+	tlbinit();
+	ioinit(1);		/* Very early to establish IO mappings */
 	arginit();
 	confinit();
 	savefpregs(&initfp);
@@ -62,6 +63,7 @@ main(void)
 	schedinit();
 }
 
+
 /*
  *  copy arguments passed by the boot kernel (or ROM) into a temporary buffer.
  *  we do this because the arguments are in memory that may be allocated
@@ -398,10 +400,15 @@ confinit(void)
 	conf.copymode = 0;		/* copy on write */
 }
 
+void
+procsave(Proc *p)
+{
+	USED(p);
 
-/*
- *  for the sake of devcons
- */
+	/* keep track of tlbfaults */
+	up->counter[TLBCNTR] += m->tlbfault - m->otlbfault;
+	m->otlbfault = m->tlbfault;
+}
 
 void
 buzz(int f, int d)
@@ -410,18 +417,53 @@ buzz(int f, int d)
 	USED(d);
 }
 
-void
-rdbginit(void)
+/*
+	register offsets of ARCS prom jmpbuf
+		JB_PC		0
+		JB_SP		1
+		JB_FP		2
+		JB_S0		3
+		JB_S1		4
+		JB_S2		5
+		JB_S3		6
+		JB_S4		7
+		JB_S5		8
+		JB_S6		9
+		JB_S7		10
+*/
+
+struct 
 {
-	memmove((void*)0xA001C000, rdbgcode, rdbglen);
-}
+	ulong	pc;
+	ulong	sp;
+	ulong	fp;
+	ulong	s[7];
+} Mipsjmpbuf;
 
 void
-procsave(Proc *p)
+rdbginit(void)
 {
-	USED(p);
+	uchar *vec;
+	ulong jba;
 
-	/* keep track of tlbfaults */
-	up->counter[TLBCNTR] += m->tlbfault - m->otlbfault;
-	m->otlbfault = m->tlbfault;
+	/* Only interested in the PC */
+	Mipsjmpbuf.pc = 0xA001C020;
+
+	/* Link an NMI handler to the debugger
+	 * - addresses from the ARCS rom source
+	 */
+	vec = (uchar*)0xA0000420;
+	jba = (ulong)UNCACHED(void, &Mipsjmpbuf);
+
+	vec[0] = 'N';
+	vec[1] = 'm';
+	vec[2] = 'i';
+	vec[3] = 's';
+	vec[4] = jba>>24;
+	vec[5] = jba>>16;
+	vec[6] = jba>>8;
+	vec[7] = jba;
+
+	/* Install the debugger code in a known place */
+	memmove((void*)0xA001C000, rdbgcode, rdbglen);
 }
diff --git a/carrera/trap.c b/carrera/trap.c
index e20e330b90c956ab559ec942c9400bfae765775c..0d7eb87b54c21560e2d60bca09484026dea5f251 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -617,7 +617,6 @@ forkchild(Proc *p, Ureg *ur)
 	memmove(cur, ur, sizeof(Ureg));
 
 	cur->pc += 4;
-	cur->status |= CU0;
 
 	/* Things from bottom of syscall we never got to execute */
 	p->psstate = 0;
diff --git a/pc/devvga.c b/pc/devvga.c
index 2c22c1771f535c96b65ec8f8ecfbdf8b05c05ab5..e8b043b3bd34e29fb72ebc874f3fba5c9fcbe6c6 100644
--- a/pc/devvga.c
+++ b/pc/devvga.c
@@ -518,9 +518,9 @@ setscreen(int maxx, int maxy, int ldepth)
 }
 
 /*
- * paste tile into soft screen.
- * tile is at location r, first pixel in *data.  tl is length of scan line to insert,
- * l is amount to advance data after each scan line.
+ *   paste tile into soft screen.
+ *   tile is at location r, first pixel in *data.  tl is length of scan line to insert,
+ *   l is amount to advance data after each scan line.
  */
 void
 screenload(Rectangle r, uchar *data, int tl, int l)
@@ -588,7 +588,7 @@ screenload(Rectangle r, uchar *data, int tl, int l)
 }
 
 /*
- *  copy litte endian soft screen to big endian hard screen
+ *  copy little endian soft screen to big endian hard screen
  */
 void
 screenupdate(void)
diff --git a/port/chan.c b/port/chan.c
index 2e3e66773dc3ad0dd38a8c89f16b611b3dc5cce8..42c440f7d64cd2e6f5e5f1fac07dcd6e3bf1b777 100644
--- a/port/chan.c
+++ b/port/chan.c
@@ -195,11 +195,20 @@ mount(Chan *new, Chan *old, int flag, char *spec)
 	}
 
 	if(m == 0) {
+		/*
+		 *  nothing mounted here yet.  create a mount
+		 *  head and add to the hash table.
+		 */
 		m = smalloc(sizeof(Mhead));
 		m->from = old;
 		incref(old);
 		m->hash = *l;
 		*l = m;
+
+		/*
+		 *  if this is a union mount, add the old
+		 *  node to the mount chain.
+		 */
 		if(order != MREPL) 
 			m->mount = newmount(m, old, 0, 0);
 	}
diff --git a/port/devcons.c b/port/devcons.c
index 3ca32fd97714fe26a83fd57da15dab2f63470cd1..7456badfc5f420b8e4c64295d651bd33e477d69b 100644
--- a/port/devcons.c
+++ b/port/devcons.c
@@ -212,6 +212,12 @@ echo(Rune r, char *buf, int n)
 		case 'r':
 			exit(0);
 			break;
+case 'q':
+print("%lux\n", *(ulong*)0xe0000004);
+print("%lux\n", *(ulong*)0x80000420);
+print("%lux\n", *(ulong*)0x80000424);
+for(pid = 0; pid < 30; pid++)
+print(":%lux\n", ((ulong*)0xbfc00000)[pid]);
 		}
 		break;
 	case 3: