From 0bfcefded9010495d808abdbd69a1d2891778b1c Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 9 Jun 1994 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1994-06-09

---
 carrera/dat.h    |   4 +-
 carrera/fptrap.c |  11 +--
 carrera/l.s      | 227 +++++++++++++++++++++--------------------------
 carrera/main.c   |   3 +-
 carrera/mem.h    |  45 +++++++++-
 carrera/trap.c   |  29 +++---
 carrera/ureg.h   |  46 ++++++++++
 pc/main.c        |   1 +
 8 files changed, 218 insertions(+), 148 deletions(-)
 create mode 100644 carrera/ureg.h

diff --git a/carrera/dat.h b/carrera/dat.h
index eb9be43835cdb535700ee3c6f3cfb607fdbb393f..d7a43a27c8821d0279a9e9ce3c4cc30e3e720759 100644
--- a/carrera/dat.h
+++ b/carrera/dat.h
@@ -15,7 +15,7 @@ typedef struct Ureg	Ureg;
 /*
  *  parameters for sysproc.c
  */
-#define AOUT_MAGIC	V_MAGIC
+#define AOUT_MAGIC	V_MAGIC || magic==M_MAGIC
 
 /*
  *  machine dependent definitions used by ../port/dat.h
@@ -81,7 +81,7 @@ struct PMMU
 struct Notsave
 {
 	ulong	svstatus;
-	ulong	svr1;
+	uvlong	svr1;
 };
 
 #include "../port/portdat.h"
diff --git a/carrera/fptrap.c b/carrera/fptrap.c
index bdf9ea7daff2e5270b5f3a4ddaa9a50ce8a2db18..2b8457ebeafcf67a422adfdf8760baaa7f3dcf25 100644
--- a/carrera/fptrap.c
+++ b/carrera/fptrap.c
@@ -34,10 +34,10 @@ fptrap(Ureg *ur)
 
 print("fpt: %d %s %lux\n", up->pid, up->text, up->fpsave.fpstatus);
 
+	iw = ur->pc;
 	if(ur->cause & (1<<31))
-		iw = *(ulong*)(ur->pc+4);
-	else
-		iw = *(ulong*)ur->pc;
+		iw += 4;
+	iw = *(ulong*)iw;
 
 	if(fpunimp(iw) == 0)
 		return;
@@ -174,7 +174,7 @@ fpunimp(ulong iw)
 	return 0;
 }
 
-static ulong*
+static uvlong*
 reg(Ureg *ur, int regno)
 {
 	/* regs go from R31 down in ureg, R29 is missing */
@@ -192,7 +192,8 @@ branch(Ureg *ur, ulong fcr31)
 {
 	ulong iw, npc, rs, rt, rd, offset;
 
-	iw = *(ulong*)ur->pc;
+	iw = ur->pc;
+	iw = *(ulong*)iw;
 	rs = (iw>>21) & 0x1F;
 	if(rs)
 		rs = *reg(ur, rs);
diff --git a/carrera/l.s b/carrera/l.s
index 7d56a4b510141c2d61355aedeb86a163892f9696..e66047db8754d444baa92a2e2915a25e0c40613f 100644
--- a/carrera/l.s
+++ b/carrera/l.s
@@ -12,10 +12,6 @@
 /*
  *  R4000 instructions
  */
-#define	LD(offset, base, rt)	WORD	$((067<<26)|((base)<<21)|((rt)<<16)|((offset)&0xFFFF))
-#define	STD(rt, offset, base)	WORD	$((077<<26)|((base)<<21)|((rt)<<16)|((offset)&0xFFFF))
-#define	DSLL(sa, rt, rd)	WORD	$(((rt)<<16)|((rd)<<11)|((sa)<<6)|070)
-#define	DSRA(sa, rt, rd)	WORD	$(((rt)<<16)|((rd)<<11)|((sa)<<6)|073)
 #define	LL(base, rt)		WORD	$((060<<26)|((base)<<21)|((rt)<<16))
 #define	SC(base, rt)		WORD	$((070<<26)|((base)<<21)|((rt)<<16))
 
@@ -26,16 +22,13 @@
  */
 TEXT	start(SB), $-4
 
-DBG(0x55aa0000)
 	MOVW	$setR30(SB), R30
 	MOVW	$(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 */
@@ -57,19 +50,14 @@ DBG(0x55aa0002)
 	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)
@@ -93,11 +81,11 @@ TEXT	touser(SB), $-4
 	MOVW	M(STATUS), R4
 	WAIT
 	AND	$(~KMODEMASK), R4
-	OR	$(KUSER|EXL|IE), R4
+	OR	$(KUSER|EXL|IE|UX), R4
 	MOVW	R4, M(STATUS)
 	WAIT
 	MOVW	R1, SP
-	MOVW	R2, M(EPC)
+	MOVV	R2, M(EPC)
 	ERET
 
 TEXT	firmware(SB), $0
@@ -286,6 +274,7 @@ TEXT	gettlbvirt(SB), $0
 	NOOP
 	RET
 
+/* also vector80 */
 TEXT	vector0(SB), $-4
 	NOOP4
 	NOOP4
@@ -372,34 +361,33 @@ TEXT	vector180(SB), $-4
 	NOOP4
 	MOVW	$exception(SB), R26
 	JMP	(R26)
-	NOP
 
 TEXT	exception(SB), $-4
 	MOVW	M(STATUS), R26
 	WAIT
 	AND	$KUSER, R26
 	BEQ	R26, waskernel
+
 wasuser:
 	CONST	(MACHADDR, R27)		/* R27 = m-> */
 	MOVW	8(R27), R26		/* R26 = m->proc */
 	MOVW	8(R26), R27		/* R27 = m->proc->kstack */
-	MOVW	SP, R26			/* save user sp */
-	ADDU	$(KSTACK-UREGSIZE-2*BY2WD), R27, SP
+	MOVV	SP, R26			/* save user sp */
+	ADDU	$(KSTACK-UREGSIZE), R27, SP
 
-	MOVW	R26, 0x10(SP)			/* user SP */
-	MOVW	R31, 0x28(SP)
-	MOVW	R30, 0x2C(SP)
+	MOVV	R26, Ureg_sp(SP)		/* user SP */
+	MOVV	R31, Ureg_r31(SP)
+	MOVV	R30, Ureg_r30(SP)
 	MOVW	M(CAUSE), R26
-	MOVW	R(MACH), 0x3C(SP)
-	MOVW	R(USER), 0x40(SP)
+	MOVV	R25, Ureg_r25(SP)		/* R(USER), R(MACH) */
+	MOVV	R24, Ureg_r24(SP)
 	AND	$(EXCMASK<<2), R26
 	SUBU	$(CSYS<<2), R26
 
 	JAL	saveregs(SB)
 
 	MOVW	$setR30(SB), R30
-	CONST	(MACHADDR, R1)
-	MOVW	R1, R(MACH)			/* R(MACH) = m-> */
+	CONST	(MACHADDR, R(MACH))		/* R(MACH) = m-> */
 	MOVW	8(R(MACH)), R(USER)		/* up = m->proc */
 	MOVW	4(SP), R1			/* first arg for syscall/trap */
 	BNE	R26, notsys
@@ -407,62 +395,60 @@ wasuser:
 	JAL	syscall(SB)
 
 sysrestore:
-	MOVW	0x28(SP), R31
-	MOVW	0x08(SP), R26
-	MOVW	0x2C(SP), R30
+	MOVV	Ureg_r31(SP), R31
+	MOVW	Ureg_status(SP), R26
+	MOVV	Ureg_r30(SP), R30
 	MOVW	R26, M(STATUS)
 	WAIT
-	MOVW	0x0C(SP), R26		/* old pc */
-	MOVW	0x10(SP), SP
-	MOVW	R26, M(EPC)
+	MOVV	Ureg_pc(SP), R26		/* old pc */
+	MOVV	Ureg_sp(SP), SP
+	MOVV	R26, M(EPC)
 	ERET
 
 notsys:
 	JAL	trap(SB)
 restore:
 	JAL	restregs(SB)
-	MOVW	0x28(SP), R31
-	MOVW	0x2C(SP), R30
-	MOVW	0x3C(SP), R(MACH)
-	MOVW	0x40(SP), R(USER)
-	MOVW	0x10(SP), SP
-	MOVW	R26, M(EPC)
+	MOVV	Ureg_r31(SP), R31
+	MOVV	Ureg_r30(SP), R30
+	MOVV	Ureg_r25(SP), R25			/* R(USER), R(MACH) */
+	MOVV	Ureg_r24(SP), R24
+	MOVV	Ureg_sp(SP), SP
+	MOVV	R26, M(EPC)
 	ERET
 
 waskernel:
-	MOVW	$1, R26			/* not syscall */
-	MOVW	SP, -(UREGSIZE-16)(SP)
+	MOVV	SP, R26
 	SUBU	$UREGSIZE, SP
-	MOVW	R31, 0x28(SP)
+	OR	$7, SP
+	XOR	$7, SP
+	MOVV	R26, Ureg_sp(SP)
+	MOVV	R31, Ureg_r31(SP)
+	MOVW	$1, R26			/* not syscall */
 	JAL	saveregs(SB)
 	MOVW	4(SP), R1		/* first arg for trap */
 	JAL	trap(SB)
 	JAL	restregs(SB)
-	MOVW	0x28(SP), R31
-	ADDU	$UREGSIZE, SP
-	MOVW	R26, M(EPC)
+	MOVV	Ureg_r31(SP), R31
+	MOVV	Ureg_sp(SP), SP
+	MOVV	R26, M(EPC)
 	ERET
 
-TEXT	forkret(SB), $0
-	MOVW	R0, R1			/* Fake out system call return */
+TEXT	forkret(SB), $-4
+	MOVV	R0, R1			/* Fake out system call return */
 	JMP	sysrestore
 
 TEXT	saveregs(SB), $-4
-	MOVW	R1, 0x9C(SP)
-	MOVW	R2, 0x98(SP)
-	/* save R5, R6 as 64 bits */
-	ADDU	$(UREGSIZE-16), SP, R1
-	MOVW	$~7, R2			/* don't let him use R28 */
-	AND		R2, R1
-	STD		(5, 0,(1))
-	STD		(6, 8,(1))
-	ADDU	$8, SP, R1
-	MOVW	R1, 0x04(SP)		/* arg to base of regs */
+	MOVV	R1, Ureg_r1(SP)		/* save early to use as temp */
+	MOVV	R2, Ureg_r2(SP)
+
+	ADDU	$Uoffset,SP, R1
+	MOVW	R1, 4(SP)		/* arg to base of regs */
 	MOVW	M(STATUS), R1
-	MOVW	M(EPC), R2
+	MOVV	M(EPC), R2
 	WAIT
-	MOVW	R1, 0x08(SP)
-	MOVW	R2, 0x0C(SP)
+	MOVW	R1, Ureg_status(SP)
+	MOVV	R2, Ureg_pc(SP)
 
 	MOVW	$(~KMODEMASK),R2	/* don't let him use R28 */
 	AND	R2, R1
@@ -471,93 +457,86 @@ TEXT	saveregs(SB), $-4
 	BEQ	R26, return		/* sys call, don't save */
 
 	MOVW	M(CAUSE), R1
-	MOVW	M(BADVADDR), R2
+	MOVV	M(BADVADDR), R2
 	NOOP
-	MOVW	R1, 0x14(SP)
-	MOVW	M(TLBVIRT), R1
+	MOVW	R1, Ureg_cause(SP)
+	MOVV	M(TLBVIRT), R1
 	NOOP
-	MOVW	R2, 0x18(SP)
-	MOVW	R1, 0x1C(SP)
+	MOVV	R2, Ureg_badvaddr(SP)
+	MOVV	R1, Ureg_tlbvirt(SP)
 	MOVW	HI, R1
 	MOVW	LO, R2
-	MOVW	R1, 0x20(SP)
-	MOVW	R2, 0x24(SP)
+	MOVV	R1, Ureg_hi(SP)
+	MOVV	R2, Ureg_lo(SP)
 					/* LINK,SB,SP missing */
-	MOVW	R28, 0x30(SP)
+	MOVV	R28, Ureg_r28(SP)
 					/* R27, R26 not saved */
 					/* R25, R24 missing */
-	MOVW	R23, 0x44(SP)
-	MOVW	R22, 0x48(SP)
-	MOVW	R21, 0x4C(SP)
-	MOVW	R20, 0x50(SP)
-	MOVW	R19, 0x54(SP)
-	MOVW	R18, 0x58(SP)
-	MOVW	R17, 0x5C(SP)
-	MOVW	R16, 0x60(SP)
-	MOVW	R15, 0x64(SP)
-	MOVW	R14, 0x68(SP)
-	MOVW	R13, 0x6C(SP)
-	MOVW	R12, 0x70(SP)
-	MOVW	R11, 0x74(SP)
-	MOVW	R10, 0x78(SP)
-	MOVW	R9, 0x7C(SP)
-	MOVW	R8, 0x80(SP)
-	MOVW	R7, 0x84(SP)
-	MOVW	R6, 0x88(SP)
-	MOVW	R5, 0x8C(SP)
-	MOVW	R4, 0x90(SP)
-	MOVW	R3, 0x94(SP)
+	MOVV	R23, Ureg_r23(SP)
+	MOVV	R22, Ureg_r22(SP)
+	MOVV	R21, Ureg_r21(SP)
+	MOVV	R20, Ureg_r20(SP)
+	MOVV	R19, Ureg_r19(SP)
+	MOVV	R18, Ureg_r18(SP)
+	MOVV	R17, Ureg_r17(SP)
+	MOVV	R16, Ureg_r16(SP)
+	MOVV	R15, Ureg_r15(SP)
+	MOVV	R14, Ureg_r14(SP)
+	MOVV	R13, Ureg_r13(SP)
+	MOVV	R12, Ureg_r12(SP)
+	MOVV	R11, Ureg_r11(SP)
+	MOVV	R10, Ureg_r10(SP)
+	MOVV	R9, Ureg_r9(SP)
+	MOVV	R8, Ureg_r8(SP)
+	MOVV	R7, Ureg_r7(SP)
+	MOVV	R6, Ureg_r6(SP)
+	MOVV	R5, Ureg_r5(SP)
+	MOVV	R4, Ureg_r4(SP)
+	MOVV	R3, Ureg_r3(SP)
 return:
 	RET
 
 TEXT	restregs(SB), $-4
 					/* LINK,SB,SP missing */
-	MOVW	0x30(SP), R28
+	MOVV	Ureg_r28(SP), R28
 					/* R27, R26 not saved */
 					/* R25, R24 missing */
-	MOVW	0x44(SP), R23
-	MOVW	0x48(SP), R22
-	MOVW	0x4C(SP), R21
-	MOVW	0x50(SP), R20
-	MOVW	0x54(SP), R19
-	MOVW	0x58(SP), R18
-	MOVW	0x5C(SP), R17
-	MOVW	0x60(SP), R16
-	MOVW	0x64(SP), R15
-	MOVW	0x68(SP), R14
-	MOVW	0x6C(SP), R13
-	MOVW	0x70(SP), R12
-	MOVW	0x74(SP), R11
-	MOVW	0x78(SP), R10
-	MOVW	0x7C(SP), R9
-	MOVW	0x80(SP), R8
-	MOVW	0x84(SP), R7
-	/*
-	 * restored below
-	 * MOVW	0x88(SP), R6
-	 * MOVW	0x8C(SP), R5
-	 */
-	MOVW	0x90(SP), R4
-	MOVW	0x94(SP), R3
-	MOVW	0x24(SP), R2
-	MOVW	0x20(SP), R1
+	MOVV	Ureg_r23(SP), R23
+	MOVV	Ureg_r22(SP), R22
+	MOVV	Ureg_r21(SP), R21
+	MOVV	Ureg_r20(SP), R20
+	MOVV	Ureg_r19(SP), R19
+	MOVV	Ureg_r18(SP), R18
+	MOVV	Ureg_r17(SP), R17
+	MOVV	Ureg_r16(SP), R16
+	MOVV	Ureg_r15(SP), R15
+	MOVV	Ureg_r14(SP), R14
+	MOVV	Ureg_r13(SP), R13
+	MOVV	Ureg_r12(SP), R12
+	MOVV	Ureg_r11(SP), R11
+	MOVV	Ureg_r10(SP), R10
+	MOVV	Ureg_r9(SP), R9
+	MOVV	Ureg_r8(SP), R8
+	MOVV	Ureg_r7(SP), R7
+	MOVV	Ureg_r6(SP), R6
+	MOVV	Ureg_r5(SP), R5
+	MOVV	Ureg_r4(SP), R4
+	MOVV	Ureg_r3(SP), R3
+
+	MOVV	Ureg_lo(SP), R2
+	MOVV	Ureg_hi(SP), R1
 	MOVW	R2, LO
 	MOVW	R1, HI
-	/* restore 64-bit R5, R6 */
-	ADDU	$(UREGSIZE-16), SP, R1
-	MOVW	$~7, R2			/* don't let him use R28 */
-	AND		R2, R1
-	LD		(0,(1), 5)
-	LD		(8,(1), 6)
-	MOVW	0x08(SP), R1
-	MOVW	0x98(SP), R2
+
+	MOVW	Ureg_status(SP), R1
+	MOVV	Ureg_r2(SP), R2
 	MOVW	R1, M(STATUS)
 	WAIT
-	MOVW	0x9C(SP), R1
-	MOVW	0x0C(SP), R26		/* old pc */
+	MOVV	Ureg_r1(SP), R1
+	MOVV	Ureg_pc(SP), R26		/* old pc */
 	RET
 
-TEXT	rfnote(SB), $0
+TEXT	rfnote(SB), $-4
 	MOVW	R1, R26			/* 1st arg is &uregpointer */
 	SUBU	$(BY2WD), R26, SP	/* pc hole */
 	JMP	restore
diff --git a/carrera/main.c b/carrera/main.c
index 658df70264c3bc3d4358f7e6ad55457a3e39c7f7..44d1abfab10b3561488984fac3a4f3da8d015a14 100644
--- a/carrera/main.c
+++ b/carrera/main.c
@@ -310,7 +310,8 @@ iomapinit(void)
 void
 vecinit(void)
 {
-	memmove((ulong*)UTLBMISS, (ulong*)vector0, 0x100);
+	memmove((ulong*)UTLBMISS, (ulong*)vector0, 0x80);
+	memmove((ulong*)XEXCEPTION, (ulong*)vector0, 0x80);
 	memmove((ulong*)CACHETRAP, (ulong*)vector100, 0x80);
 	memmove((ulong*)EXCEPTION, (ulong*)vector180, 0x80);
 
diff --git a/carrera/mem.h b/carrera/mem.h
index b5b062b4c672e6aee21e420720958bcf82206555..23feecd918cc66c8c40a16254caa72214d7b2ebc 100644
--- a/carrera/mem.h
+++ b/carrera/mem.h
@@ -66,6 +66,7 @@
 #define ERL		0x00000004
 #define KSUPER		0x00000008
 #define KUSER		0x00000010
+#define UX		0x00000020
 #define INTMASK		0x0000ff00
 #define INTR0		0x00000100
 #define INTR1		0x00000200
@@ -98,8 +99,48 @@
  * Fundamental addresses
  */
 #define	MACHADDR	(KTZERO-MAXMACH*BY2PG)	/* warning: rdbg is near here */
-/* Sizeof(Ureg)+R5,R6+16 bytes slop+retpc & ur */
-#define	UREGSIZE	0xC0		
+/* Sizeof(Ureg)+retpc & ur+16 bytes slop */
+#define	UREGSIZE	(36*8 + 2*4 + 2*4 + 16)
+#define	Uoffset		8
+
+#define	Ureg_status	(Uoffset+0)
+#define	Ureg_cause	(Uoffset+4)
+#define	Ureg_pc		(Uoffset+8)
+#define	Ureg_sp		(Uoffset+16)
+#define	Ureg_badvaddr	(Uoffset+24)
+#define	Ureg_tlbvirt	(Uoffset+32)
+#define	Ureg_hi		(Uoffset+40)
+#define	Ureg_lo		(Uoffset+48)
+#define	Ureg_r31	(Uoffset+56)
+#define	Ureg_r30	(Uoffset+64)
+#define	Ureg_r28	(Uoffset+72)
+#define	Ureg_r27	(Uoffset+80)
+#define	Ureg_r26	(Uoffset+88)
+#define	Ureg_r25	(Uoffset+96)
+#define	Ureg_r24	(Uoffset+104)
+#define	Ureg_r23	(Uoffset+112)
+#define	Ureg_r22	(Uoffset+120)
+#define	Ureg_r21	(Uoffset+128)
+#define	Ureg_r20	(Uoffset+136)
+#define	Ureg_r19	(Uoffset+144)
+#define	Ureg_r18	(Uoffset+152)
+#define	Ureg_r17	(Uoffset+160)
+#define	Ureg_r16	(Uoffset+168)
+#define	Ureg_r15	(Uoffset+176)
+#define	Ureg_r14	(Uoffset+184)
+#define	Ureg_r13	(Uoffset+192)
+#define	Ureg_r12	(Uoffset+200)
+#define	Ureg_r11	(Uoffset+208)
+#define	Ureg_r10	(Uoffset+216)
+#define	Ureg_r9		(Uoffset+224)
+#define	Ureg_r8		(Uoffset+232)
+#define	Ureg_r7		(Uoffset+240)
+#define	Ureg_r6		(Uoffset+248)
+#define	Ureg_r5		(Uoffset+256)
+#define	Ureg_r4		(Uoffset+264)
+#define	Ureg_r3		(Uoffset+272)
+#define	Ureg_r2		(Uoffset+280)
+#define	Ureg_r1		(Uoffset+288)
 #define	MACHP(n)	((Mach *)(MACHADDR+(n)*BY2PG))
 
 /*
diff --git a/carrera/trap.c b/carrera/trap.c
index a79f4e013621e7b50c49e1108835a15222e67451..b9d20067c6d9089afa216e9521018719914d20f9 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -253,7 +253,7 @@ trap(Ureg *ur)
 			postnote(up, 1, buf, NDebug);
 			break;
 		}
-		print("kernel %s pc=%lux\n", excname[ecode], ur->pc);
+		print("kernel %s pc=%llux\n", excname[ecode], ur->pc);
 		dumpregs(ur);
 		dumpstack();
 		if(m->machno == 0)
@@ -373,7 +373,7 @@ fpexcname(Ureg *ur, ulong fcr31, char *buf)
 {
 	int i;
 	char *s;
-	ulong fppc;
+	uvlong fppc;
 
 	fppc = ur->pc;
 	if(ur->cause & (1<<31))	/* branch delay */
@@ -392,7 +392,7 @@ fpexcname(Ureg *ur, ulong fcr31, char *buf)
 	if(s == 0)
 		return "no floating point exception";
 
-	sprint(buf, "%s fppc=0x%lux", s, fppc);
+	sprint(buf, "%s fppc=0x%llux", s, fppc);
 	return buf;
 }
 
@@ -402,7 +402,7 @@ void
 kernfault(Ureg *ur, int code)
 {
 	print("kfault %s badvaddr=0x%lux\n", excname[code], ur->badvaddr);
-	print("UP=0x%lux SR=0x%lux PC=0x%lux R31=%lux SP=0x%lux\n",
+	print("UP=0x%lux SR=0x%lux PC=0x%llux R31=%llux SP=0x%llux\n",
 				up, ur->status, ur->pc, ur->r31, ur->sp);
 
 	dumpregs(ur);
@@ -465,10 +465,10 @@ notify(Ureg *ur)
 	n = &up->note[0];
 	if(strncmp(n->msg, "sys:", 4) == 0) {
 		l = strlen(n->msg);
-		if(l > ERRLEN-15)	/* " pc=0x12345678\0" */
-			l = ERRLEN-15;
+		if(l > ERRLEN-23)	/* " pc=0x12345678\0" */
+			l = ERRLEN-23;
 
-		sprint(n->msg+l, " pc=0x%lux", ur->pc);
+		sprint(n->msg+l, " pc=0x%llux", ur->pc);
 	}
 
 	if(n->flag != NUser && (up->notified || up->notify==0)) {
@@ -490,10 +490,11 @@ notify(Ureg *ur)
 		pexit(n->msg, n->flag!=NDebug);
 	}
 	up->svstatus = ur->status;
-	sp = ur->usp - sizeof(Ureg);
+	sp = ur->usp & ~(BY2V-1);
+	sp -= sizeof(Ureg);
 
-	if(sp&0x3 || !okaddr((ulong)up->notify, BY2WD, 0)
-	|| !okaddr(sp-ERRLEN-3*BY2WD, sizeof(Ureg)+ERRLEN-3*BY2WD, 1)) {
+	if(!okaddr((ulong)up->notify, BY2WD, 0) ||
+	   !okaddr(sp-ERRLEN-3*BY2WD, sizeof(Ureg)+ERRLEN-3*BY2WD, 1)) {
 		pprint("suicide: bad address or sp in notify\n");
 		qunlock(&up->debug);
 		pexit("Suicide", 0);
@@ -507,8 +508,8 @@ notify(Ureg *ur)
 	*(ulong*)(sp+2*BY2WD) = sp+3*BY2WD;	/* arg 2 is string */
 	up->svr1 = ur->r1;			/* save away r1 */
 	ur->r1 = (ulong)up->ureg;		/* arg 1 is ureg* */
-	*(ulong*)(sp+1*BY2WD) = (ulong)up->ureg;	/* arg 1 0(FP) is ureg* */
-	*(ulong*)(sp+0*BY2WD) = 0;		/* arg 0 is pc */
+	((ulong*)sp)[1] = (ulong)up->ureg;	/* arg 1 0(FP) is ureg* */
+	((ulong*)sp)[0] = 0;			/* arg 0 is pc */
 	ur->usp = sp;
 	ur->pc = (ulong)up->notify;
 	up->notified = 1;
@@ -607,13 +608,13 @@ syscall(Ureg *aur)
 		goto error;
 
 	if(up->scallnr >= nsyscall){
-		pprint("bad sys call %d pc %lux\n", up->scallnr, ur->pc);
+		pprint("bad sys call %d pc %llux\n", up->scallnr, ur->pc);
 		postnote(up, 1, "sys: bad sys call", NDebug);
 		error(Ebadarg);
 	}
 
 	if(sp & (BY2WD-1)){
-		pprint("odd sp in sys call pc %lux sp %lux\n", ur->pc, ur->sp);
+		pprint("odd sp in sys call pc %llux sp %llux\n", ur->pc, ur->sp);
 		postnote(up, 1, "sys: odd stack", NDebug);
 		error(Ebadarg);
 	}
diff --git a/carrera/ureg.h b/carrera/ureg.h
new file mode 100644
index 0000000000000000000000000000000000000000..e3f37f5be4407a2707344b73a8933ff47fc83564
--- /dev/null
+++ b/carrera/ureg.h
@@ -0,0 +1,46 @@
+
+struct Ureg
+{
+	ulong	status;
+	ulong	cause;
+	uvlong	pc;
+	union{
+		uvlong	sp;
+		uvlong	usp;
+	};
+	uvlong	badvaddr;
+	uvlong	tlbvirt;
+
+	uvlong	hi;
+	uvlong	lo;
+	uvlong	r31;
+	uvlong	r30;
+	uvlong	r28;
+	uvlong	r27;
+	uvlong	r26;
+	uvlong	r25;
+	uvlong	r24;
+	uvlong	r23;
+	uvlong	r22;
+	uvlong	r21;
+	uvlong	r20;
+	uvlong	r19;
+	uvlong	r18;
+	uvlong	r17;
+	uvlong	r16;
+	uvlong	r15;
+	uvlong	r14;
+	uvlong	r13;
+	uvlong	r12;
+	uvlong	r11;
+	uvlong	r10;
+	uvlong	r9;
+	uvlong	r8;
+	uvlong	r7;
+	uvlong	r6;
+	uvlong	r5;
+	uvlong	r4;
+	uvlong	r3;
+	uvlong	r2;
+	uvlong	r1;
+};
diff --git a/pc/main.c b/pc/main.c
index 9f3474ffa52de25a5fb1b589889299638e1299d5..5ddc339d6bc627660bf1542a5d2611057c0a4180 100644
--- a/pc/main.c
+++ b/pc/main.c
@@ -63,6 +63,7 @@ main(void)
 	chandevreset();
 	swapinit();
 	userinit();
+print("CR0 %lux\n", getcr0());
 	schedinit();
 }