From b066eacb9b83637b113eb042641e3a286fedd805 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 22 May 1994 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1994-05-22

---
 carrera/l.s   | 12 +++++++++++-
 carrera/mem.h |  6 +++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/carrera/l.s b/carrera/l.s
index ea07a3e4611695c8302adffd0f0ae3d10ef59968..eb7c65273a3bfac9b97f1bc4f4e554e7520a3960 100644
--- a/carrera/l.s
+++ b/carrera/l.s
@@ -20,18 +20,23 @@
 #define	LL(base, rt)		WORD	$((060<<26)|((base)<<21)|((rt)<<16))
 #define	SC(base, rt)		WORD	$((070<<26)|((base)<<21)|((rt)<<16))
 
+#define DBG(S)	CONST(0xa0001000, R20);CONST(S, R21);MOVW	R21,(R20)
+
 /*
  * Boot first processor
  */
 TEXT	start(SB), $-4
 
+DBG(0x55aa0000)
 	MOVW	$setR30(SB), R30
-	MOVW	$(CU1|INTR7|INTR6|INTR5|INTR4|INTR3|INTR2|INTR1|INTR0), R1
+	MOVW	$(BEV|DE|CU1|INTR7|INTR6|INTR5|INTR4|INTR3|INTR2|INTR1|INTR0), R1
 	MOVW	R1, M(STATUS)
 	WAIT
+DBG(0x55aa0001)
 
 	MOVW	$TLBROFF, R1
 	MOVW	R1, M(WIRED)
+DBG(0x55aa0002)
 
 	MOVW	$((0x1C<<7)|(1<<24)), R1
 	MOVW	R1, FCR31	/* permit only inexact and underflow */
@@ -53,14 +58,19 @@ TEXT	start(SB), $-4
 	MOVD	F24, F18
 	MOVD	F24, F20
 	MOVD	F24, F22
+DBG(0x55aa0003)
 
 	MOVW	$MACHADDR, R(MACH)
 	ADDU	$(BY2PG-4), R(MACH), SP
 	MOVW	$0, R(USER)
+DBG(0x55aa0010)
+MOVW R(MACH),4(R20)
 	MOVW	R0, 0(R(MACH))
+DBG(0x55aa0011)
 
 	MOVW	$edata(SB), R1
 	MOVW	$end(SB), R2
+DBG(0x55aa0004)
 
 clrbss:
 	MOVB	$0, (R1)
diff --git a/carrera/mem.h b/carrera/mem.h
index 13c47ad859e484451ff35e380dd85ed6a4223f6e..d8a273b15e0c28ae5f729d5e28aa7cf98a4bf88e 100644
--- a/carrera/mem.h
+++ b/carrera/mem.h
@@ -75,8 +75,8 @@
 #define INTR5		0x00002000
 #define INTR6		0x00004000
 #define INTR7		0x00008000
-#define ISC		0x00010000
-#define SWC		0x00020000
+#define DE		0x00010000
+#define BEV		0x00400000
 #define CU0		0x10000000
 #define CU1		0x20000000
 
@@ -162,7 +162,7 @@
 #define	TSTKTOP	(0xC0000000+USTKSIZE-BY2PG) /* top of temporary stack */
 #define	TSTKSIZ 100
 #define	KZERO	KSEG0			/* base of kernel address space */
-#define	KTZERO	(KZERO+0x20000)		/* first address in kernel text */
+#define	KTZERO	(KZERO+0x2000)		/* first address in kernel text */
 #define	USTKSIZE	(4*1024*1024)	/* size of user stack */
 #define globalmem(x)	(((ulong)x)&KZERO)	/* addresses valid in all contexts */
 /*