--- xinu/sys/startup.s	2018/04/24 17:39:02	1.1.1.1
+++ xinu/sys/startup.s	2018/04/24 17:39:28	1.1.1.2
@@ -1,99 +1,12 @@
-/* startup.s - start */
+.globl _console
+.data
+_console: .long 0	   | for printf, etc.
+.text
+DISABLE = 0x2700
 
-#include <procreg.h>
-#include <conf.h>
-#include <kernel.h>
-#include <mach.h>
+	movw #DISABLE,sr  | make sure no ints for startup
+	jsr _sizmem       | find out how much mem we have
+	movel _maxaddr,sp  | relocate stack there
+	jmp _nulluser      | and run nulluser
 
-#define	PSLDISAB	0x001f0000	/* initial PSL -- interrupts	*/
-					/* disabled, on kernel stack,	*/
-					/* kernel mode			*/
 
-/*----------------------------------------------------------------------------
- *  Xinu system entry point -- first location beyond interrupt vectors
- *  assumption: processor is in kernel mode on entry 
- *----------------------------------------------------------------------------
-*/
-	.text
-	.globl	start
-	.globl	_restart
-start:					/* boot utility entry pt	*/
-_restart:				/* shell reboot cmd entry pt	*/
-	nop; nop			/* == .word 0x0101; can jmp to	*/
-					/* start or calls $0, start	*/
-	mtpr	$DISABLE, $IPL		/* disable interrupts 		*/
-#if defined(VAX750) || defined(VAX730) || defined(VAX725) || \
-    defined(UVAX)
-	mtpr	$IURSET, $IUR		/* reset the bus		*/
-	mtpr	$IURUNSET, $IUR		/* unreset the bus		*/
-#endif
-	mtpr	$intstk, $ISP		/* interrupt stack given memory	*/
-	mtpr	$NOMAP, $MAPEN		/* disable memory management	*/
-	movab	_end, r2		/* zero out bss	(just in case)	*/
- 	movab	_edata, r1
-clrbss:
-	clrb	(r1)+
-	cmpl	r1, r2			/* more bss to zero?		*/
-	jlssu	clrbss			/* yes => back to clrbss	*/
-	mtpr	$lowcore, $SCBB		/* sys ctrl blck pts to vectors	*/
-	mtpr	_nullpcb, $PCBB		/* PCBB points to null process'	*/
-					/* process control block entry	*/
-					/* in proctab[]			*/
-					/* set up nulluser's proc ctrl	*/
-	movl	_nullpcb, r1 		/* block--init all general reg	*/
-	addl3	$72, r1, r0		/* clear fp first, then r12-r0	*/
-pcbloop:				/* then 4 stack pointers	*/
-	clrl	-(r0)
-	cmpl	r0, r1
-	jgtru	pcbloop
-	moval	kernstk, (r0)		/* stack pointer given memory--	*/
-					/* kernstk used for now		*/
-	movab	pcbcont, 72(r0)		/* PC points to pcbcont		*/
-	movl	$PSLDISAB, 76(r0)	/* initial psl, interrupts 	*/
-					/* disabled, on kernel stack	*/
-	movl	$INITBR, 80(r0)		/* set P0BR			*/
-	movl	$INITLR, 84(r0)		/* AST lvl set to none pending,	*/
-					/* P0LR set to 0		*/
-	movl	$INITBR, 88(r0)		/* set P1BR			*/
-	clrl	92(r0)			/* set P1LR			*/
-	ldpctx				/* load new context		*/
-	rei				/* resume at pcbcont		*/
-pcbcont:				/* set all pertinent internal	*/
-					/* processor registers		*/
-					/*   (it may not be necessary	*/
-					/*    to set all of these)	*/
-					/* (r0 is now 0)		*/
-	mtpr	r0, $SISR		/* clear software intrpt summary*/
-	mtpr	r0, $ICCS		/* clear interval clock csr	*/
-	mtpr	r0, $RXCS		/* clr cons recv intrrpt enable	*/
-	mfpr	$SID, r1		/* get system id register value	*/
-	bicl2	$SYSTYPE, r1		/* mask off system id		*/
-	movl 	r1, _machinesid		/* move machine system id 	*/
-	mfpr	$RXDB, r1		/* clear incoming byte if any	*/
-	mtpr	r0, $TXCS		/* clear cons trans int enable	*/
-#if	defined(VAX750) || defined(VAX730) || defined(VAX725) || \
-	defined(UVAX)
-	mtpr	$3, $TBDR		/* disable translation buffer	*/
-	mtpr	$MCESRCLR, $MCESR	/* clear machine check error reg*/
-	mtpr	r0, $CAER		/* clear cache error register	*/
-	mtpr	r0, $CADR		/* enable cache 		*/
-#endif
-#if	defined(VAX780) || defined(VAX785)
-	mtpr	r0, $SBIFS		/* clear SBI fault and status	*/
-	mtpr	r0, $SBIER		/* clear SBI error register	*/
-#endif
-#if defined(VAX8600)
-	mtpr	$0, $EHSR		/* clear error handling status	*/
-#endif
-	mtpr	r0, $TBIA		/* clear trans buffer inval all	*/
-	calls	$0, sizmem		/* _maxaddr set to max address	*/
-	movl	_maxaddr, sp		/* switch stack to high memory	*/
-	calls	$0, _nulluser		/* Run C startup routine	*/
-					/* nulluser should never return	*/
-	pushab	errmes			/* trap return to startup	*/
-	calls	$1, _kprintf
-	jmp	__halt
-
-	.data	1
-errmes:
-	.ascii	"error--nulluser returned to startup\n\0"