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1.1 root 1: /*
2: * Copyright (c) 1980, 1986 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: /* "@(#)utboot.s 7.1 (Berkeley) 6/5/86" */
8:
9: /*
10: * VAX tape boot block for distribution tapes
11: * works on unibus tm03
12: *
13: * reads a program from a tp directory on a tape and executes it
14: * program must be stripped of the header and is loaded ``bits as is''
15: * you can return to this loader via ``ret'' as you are called ``calls $0,ent''
16: */
17: .set RELOC,0x70000
18: /* a.out defines */
19: .set HDRSIZ,040 /* size of file header for VAX */
20: .set MAGIC,0410 /* file type id in header */
21: .set TSIZ,4 /* text size */
22: .set DSIZ,8 /* data size */
23: .set BSIZ,12 /* bss size */
24: .set TENT,024 /* task header entry loc */
25: /* tp directory definitions */
26: .set FILSIZ,38 /* tp direc offset for file size */
27: .set BNUM,44 /* tp dir offset for start block no. */
28: .set ENTSIZ,64 /* size of 1 TP dir entry, bytes */
29: .set PTHSIZ,32 /* size of TP path name, bytes */
30: .set BLKSIZ,512 /* tape block size, bytes */
31: .set NUMDIR,24 /* no. of dir blocks on tape */
32: .set ENTBLK,8 /* no. of dir entries per tape block */
33: /* processor registers and bits */
34: .set RXCS,32
35: .set RXDB,33
36: .set TXCS,34
37: .set TXDB,35
38: .set RXCS_DONE,0x80
39: .set TXCS_RDY,0x80
40: .set TXCS_pr,7 /* bit position of TXCS ready bit */
41: .set RXCS_pd,7 /* bit position of RXCS done bit */
42: /* UBA registers */
43: .set UBA_DPR1,68
44: .set UBA_MAP,2048
45: .set BNE,0x80000000
46: .set MRV,0x80000000
47: .set MR_BDP1,0x200000
48:
49: /* UT UBA registers */
50: .set UTCS1,0
51: .set UTWC,02
52: .set UTBA,04
53: .set UTFC,06
54: .set UTCS2,010
55: .set UTDS,012
56: .set UTER,014
57: .set UTAS,016
58: .set UTCC,020
59: .set UTDB,022
60: .set UTMR,024
61: .set UTDT,026
62: .set UTSN,030
63: .set UTTC,032
64:
65: /* UT commands and bits */
66: .set GO,01
67: .set UT_REW,0x6
68: .set UT_RCOM,0x38
69: .set UT_SREV,0x1a
70: .set UT_DCLR,0x8
71: .set UT_crdy,7 /* bit pos. */
72: .set UT_gapsd,13 /* bit; aka "positioning in progress" */
73: .set UTDENS,0x4c0 /* 1600 bpi, PDP-11 format */
74: /* local stack variables */
75: .set tapa,-4 /* desired tape addr */
76: .set mtapa,-8 /* current tape addr */
77: .set name,-8-PTHSIZ /* operator-typed file name */
78: /* register usage */
79: .set rUBA,r10
80: .set rUT,r11
81: /* ===== */
82:
83: /* initialization */
84: init:
85: movl $RELOC,fp /* core loc to which to move this program */
86: addl3 $name,fp,sp /* set stack pointer; leave room for locals */
87: clrl r0
88: 1:
89: movc3 $end,(r0),(fp) /* move boot up to relocated position */
90: jmp start+RELOC
91: start:
92: bsbw rew /* rewind input tape */
93: movab name(fp),r4 /* start of filename storage */
94: movzbl $'=,r0 /* prompt character */
95: bsbw putc /* output char to main console */
96: /* read in a file name */
97: movl r4,r1 /* loc at which to store file name */
98: nxtc:
99: bsbw getc /* get input char's in file name */
100: cmpb r0,$012 /* terminator ? */
101: beql nullc
102: movb r0,(r1)+
103: brb nxtc
104: nullc:
105: subl3 r4,r1,r9 /* size of path name */
106: beql start /* dumb operator */
107: clrb (r1)+
108: incl r9
109: /* user-specified TP filename has been stored at name(fp) */
110: /* read in entire tp directory contents into low core */
111: dirred:
112: movl $8,tapa(fp) /* tp directory starts at block 8 */
113: movl $(NUMDIR*BLKSIZ),r6 /* no. bytes in total dir */
114: bsbw taper /* read no. bytes indicated */
115: /* search entire directory for user-specified file name */
116: clrl r5 /* dir buff loc = 0 */
117: nxtdir:
118: cmpc3 r9,(r5),(r4) /* see if dir entry matches filename */
119: beql fndfil /* found match */
120: acbl $NUMDIR*BLKSIZ-1,$ENTSIZ,r5,nxtdir
121: /* see if done with tp dir */
122: brw start /* entry not in directory; start over */
123: /* found desired tp dir entry */
124: fndfil:
125: movzwl BNUM(r5),tapa(fp) /* start block no., 2 bytes */
126: addl2 $7,tapa(fp) /* skip 7 boot blocks */
127: movzwl FILSIZ(r5),r6 /* low 2 bytes file size */
128: insv FILSIZ-1(r5),$16,$8,r6 /* file size, high byte */
129: cmpl r6,$RELOC-512 /* check if file fits below stack */
130: blss filok /* file o.k. */
131: brw start /* file too large */
132: /* time to read in desired file from tape */
133: filok:
134: movl r6,r7 /* save r6 */
135: bsbb taper
136: bsbw rew
137: /* clear core */
138: subl3 r7,$RELOC-4,r0 /* no. bytes to clear */
139: 1:
140: clrb (r7)+
141: sobgtr r0,1b
142: /* time to jump to start of file & execute */
143: addl3 $20,fp,ap
144: clrl r5
145: calls $0,(r5)
146: brw start
147: /* taper: movcTAPE (r6),tapa(fp),0 */
148: rew2:
149: bsbb rew /* beginning of tape */
150: taper0:
151: bsbb rrec /* advance 1 block; never want blk 0 */
152: taper:
153: clrl r0 /* page no. */
154: cmpl mtapa(fp),tapa(fp) /* current position .vs. desired */
155: bgtr rew2
156: blss taper0
157: 1:
158: bsbb rrec
159: acbl $1,$-BLKSIZ,r6,1b
160: rsb
161: /* rew: rewind the tape */
162: rew:
163: clrl mtapa(fp) /* current position */
164: movw $UTDENS,UTTC(%rUT) /* select drive */
165: movw $UT_REW+GO,UTCS1(%rUT)
166: rsb
167: /* rrec: read 1 block from mag tape into page (r0) */
168: rrec:
169: /* pushl r0; movzbl $'r,r0; bsbw putc; movl (sp)+,r0; */
170: jsb utquiet
171: movw $-BLKSIZ,UTFC(%rUT)
172: movw $-256,UTWC(%rUT) /* !!!!!!!!!!!!!! */
173: bisl3 $MRV|MR_BDP1,r0,UBA_MAP(%rUBA)
174: movw $0,UTBA(%rUT)
175: movw $UTDENS,UTTC(%rUT) /* select drive */
176: movw $UT_RCOM+GO,UTCS1(%rUT)
177: jsb utquiet
178: bisl2 $BNE,UBA_DPR1(%rUBA)
179: tstw UTER(%rUT)
180: jgeq 2f
181: mnegw $1,UTWC(%rUT)
182: movw $UTDENS,UTTC(%rUT) /* select drive */
183: movw $UT_SREV+GO,UTCS1(%rUT)
184: jmp rrec
185: 2:
186: incl r0 /* next page no. */
187: incl mtapa(fp) /* mag tape block position */
188: rsb
189: getc:
190: mfpr $RXCS,r0
191: bbc $RXCS_pd,r0,getc /* receiver ready ? */
192: mfpr $RXDB,r0
193: extzv $0,$7,r0,r0
194: cmpb r0,$015
195: bneq putc
196: bsbb putc
197: movb $0,r0
198: bsbb putc
199: movb $012,r0
200: putc:
201: mfpr $TXCS,r2
202: bbc $TXCS_pr,r2,putc /* transmitter ready ? */
203: extzv $0,$7,r0,r0
204: mtpr r0,$TXDB
205: rsb
206: utquiet:
207: movw UTCS1(%rUT),r2
208: bbc $UT_crdy,r2,utquiet
209: 1:
210: movw UTDS(%rUT),r2
211: bbs $UT_gapsd,r2,1b
212: rsb
213: end:
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