xref: /csrg-svn/sys/vax/mdec/raboot.c (revision 23769)
1 /*
2  * Copyright (c) 1980 Regents of the University of California.
3  * All rights reserved.  The Berkeley software License Agreement
4  * specifies the terms and conditions for redistribution.
5  */
6 
7 /* "@(#)raboot.c	6.3 (Berkeley) 06/26/85" */
8 
9 /*
10  * UDA50 1st level boot program: loads next 7.5Kbytes from
11  * boot sector of file system and sets it up to run.
12  */
13 	.set	RELOC,0x50000
14 	.set	BOOTLAST,15		/* last boot sector */
15 	.set	RABPSECT,512		/* bytes per sector */
16 
17 init:
18 	.word	0  			/* entry mask for dec monitor */
19 	nop;nop;nop;nop;nop;nop;nop;nop /* some no-ops for 750 boot to skip */
20 	nop;nop;
21 start:
22 	movl	r1,r7			/* UNIBUS I/O page address */
23 	movl	r2,r8			/* boot device CSR */
24 	movl	r3,r9			/* unit number */
25 	movl	r5,r11			/* boot flags */
26 	movl	$RELOC,sp
27 	moval	init,r10
28 	movc3	$end,(r10),(sp)
29 	movl	r7,r1			/* UNIBUS I/O page address */
30 	movl	r8,r2			/* boot device CSR */
31 	movl	r9,r3			/* unit number */
32 	jmp	*$RELOC+start2
33 /* now running relocated */
34 /* bring in the boot program */
35 start2:					/* running relocated */
36 	pushr	$0xffff			/* BEGIN FIREWALL */
37 	movl	$1,r4			/* first boot sector */
38 	clrl	r5			/* transfer address */
39 	clrl	-(sp)			/* transfer address */
40 1:
41 	movl	r4,r8			/* requested sector # */
42 	jsb	(r6)			/* call ROM-based driver */
43 	blbs	r0,2f
44 	halt				/* read error */
45 2:
46 	addl2	$RABPSECT,r5		/* bump address */
47 	movl	r5,(sp)
48 	aobleq	$BOOTLAST,r4,1b
49 
50 	.set	PROGSIZE,((BOOTLAST-1)*RABPSECT)
51 done:
52 	tstl	(sp)+			/* pop address */
53 	popr	$0xffff			/* END FIREWALL */
54 	movl	$PROGSIZE,r3
55 clrcor:
56 	clrq	(r3)
57 	acbl	$RELOC,$8,r3,clrcor
58 /* start loaded program */
59 	movl	$9,r10			/* major("/dev/ra0a") */
60 	calls	$0,*$0
61 	brw	start2
62 end:
63