Commit | Line | Data |
---|---|---|
7890b1d6 C |
1 | /* |
2 | * VAX tape boot block for distribution tapes | |
3 | * works on unibus tm03 | |
4 | * | |
5 | * reads a program from a tp directory on a tape and executes it | |
6 | * program must be stripped of the header and is loaded ``bits as is'' | |
7 | * you can return to this loader via ``ret'' as you are called ``calls $0,ent'' | |
8 | */ | |
9 | .set RELOC,0x70000 | |
10 | /* a.out defines */ | |
11 | .set HDRSIZ,040 /* size of file header for VAX */ | |
12 | .set MAGIC,0410 /* file type id in header */ | |
13 | .set TSIZ,4 /* text size */ | |
14 | .set DSIZ,8 /* data size */ | |
15 | .set BSIZ,12 /* bss size */ | |
16 | .set TENT,024 /* task header entry loc */ | |
17 | /* tp directory definitions */ | |
18 | .set FILSIZ,38 /* tp direc offset for file size */ | |
19 | .set BNUM,44 /* tp dir offset for start block no. */ | |
20 | .set ENTSIZ,64 /* size of 1 TP dir entry, bytes */ | |
21 | .set PTHSIZ,32 /* size of TP path name, bytes */ | |
22 | .set BLKSIZ,512 /* tape block size, bytes */ | |
23 | .set NUMDIR,24 /* no. of dir blocks on tape */ | |
24 | .set ENTBLK,8 /* no. of dir entries per tape block */ | |
25 | /* processor registers and bits */ | |
26 | .set RXCS,32 | |
27 | .set RXDB,33 | |
28 | .set TXCS,34 | |
29 | .set TXDB,35 | |
30 | .set RXCS_DONE,0x80 | |
31 | .set TXCS_RDY,0x80 | |
32 | .set TXCS_pr,7 /* bit position of TXCS ready bit */ | |
33 | .set RXCS_pd,7 /* bit position of RXCS done bit */ | |
34 | /* UBA registers */ | |
35 | .set UBA_DPR1,68 | |
36 | .set UBA_MAP,2048 | |
37 | .set BNE,0x80000000 | |
38 | .set MRV,0x80000000 | |
39 | .set MR_BDP1,0x200000 | |
40 | /* TM UBA registers */ | |
41 | .set TMER,0 | |
42 | .set TMCS,2 | |
43 | .set TMBC,4 | |
44 | .set TMBA,6 | |
45 | /* TM commands and bits */ | |
46 | .set GO,1 | |
47 | .set TM_REW,016 | |
48 | .set TM_RCOM,02 | |
49 | .set TM_SREV,012 | |
50 | .set TM_DCLR,010000 | |
51 | .set TM_crdy,7 | |
52 | .set TM_gapsd,3 | |
53 | .set TMDENS,0 /* 1600 bpi */ | |
54 | /* local stack variables */ | |
55 | .set tapa,-4 /* desired tape addr */ | |
56 | .set mtapa,-8 /* current tape addr */ | |
57 | .set name,-8-PTHSIZ /* operator-typed file name */ | |
58 | /* register usage */ | |
59 | .set rUBA,r10 | |
60 | .set rTM,r11 | |
61 | /* ===== */ | |
62 | ||
63 | /* initialization */ | |
64 | init: | |
65 | movl $RELOC,fp /* core loc to which to move this program */ | |
66 | addl3 $name,fp,sp /* set stack pointer; leave room for locals */ | |
67 | clrl r0 | |
68 | 1: | |
69 | movc3 $end,(r0),(fp) /* move boot up to relocated position */ | |
70 | jmp start+RELOC | |
71 | start: | |
72 | bsbw rew /* rewind input tape */ | |
73 | movab name(fp),r4 /* start of filename storage */ | |
74 | movzbl $'=,r0 /* prompt character */ | |
75 | bsbw putc /* output char to main console */ | |
76 | /* read in a file name */ | |
77 | movl r4,r1 /* loc at which to store file name */ | |
78 | nxtc: | |
79 | bsbw getc /* get input char's in file name */ | |
80 | cmpb r0,$012 /* terminator ? */ | |
81 | beql nullc | |
82 | movb r0,(r1)+ | |
83 | brb nxtc | |
84 | nullc: | |
85 | subl3 r4,r1,r9 /* size of path name */ | |
86 | beql start /* dumb operator */ | |
87 | clrb (r1)+ | |
88 | incl r9 | |
89 | /* user-specified TP filename has been stored at name(fp) */ | |
90 | /* read in entire tp directory contents into low core */ | |
91 | dirred: | |
92 | movl $8,tapa(fp) /* tp directory starts at block 8 */ | |
93 | movl $(NUMDIR*BLKSIZ),r6 /* no. bytes in total dir */ | |
94 | bsbw taper /* read no. bytes indicated */ | |
95 | /* search entire directory for user-specified file name */ | |
96 | clrl r5 /* dir buff loc = 0 */ | |
97 | nxtdir: | |
98 | cmpc3 r9,(r5),(r4) /* see if dir entry matches filename */ | |
99 | beql fndfil /* found match */ | |
100 | acbl $NUMDIR*BLKSIZ-1,$ENTSIZ,r5,nxtdir | |
101 | /* see if done with tp dir */ | |
102 | brw start /* entry not in directory; start over */ | |
103 | /* found desired tp dir entry */ | |
104 | fndfil: | |
105 | movzwl BNUM(r5),tapa(fp) /* start block no., 2 bytes */ | |
106 | addl2 $7,tapa(fp) /* skip 7 boot blocks */ | |
107 | movzwl FILSIZ(r5),r6 /* low 2 bytes file size */ | |
108 | insv FILSIZ-1(r5),$16,$8,r6 /* file size, high byte */ | |
109 | cmpl r6,$RELOC-512 /* check if file fits below stack */ | |
110 | blss filok /* file o.k. */ | |
111 | brw start /* file too large */ | |
112 | /* time to read in desired file from tape */ | |
113 | filok: | |
114 | movl r6,r7 /* save r6 */ | |
115 | bsbb taper | |
116 | bsbw rew | |
117 | /* clear core */ | |
118 | subl3 r7,$RELOC-4,r0 /* no. bytes to clear */ | |
119 | 1: | |
120 | clrb (r7)+ | |
121 | sobgtr r0,1b | |
122 | /* time to jump to start of file & execute */ | |
123 | addl3 $20,fp,ap | |
124 | clrl r5 | |
125 | calls $0,(r5) | |
126 | brw start | |
127 | /* taper: movcTAPE (r6),tapa(fp),0 */ | |
128 | rew2: | |
129 | bsbb rew /* beginning of tape */ | |
130 | taper0: | |
131 | bsbb rrec /* advance 1 block; never want blk 0 */ | |
132 | taper: | |
133 | clrl r0 /* page no. */ | |
134 | cmpl mtapa(fp),tapa(fp) /* current position .vs. desired */ | |
135 | bgtr rew2 | |
136 | blss taper0 | |
137 | 1: | |
138 | bsbb rrec | |
139 | acbl $1,$-BLKSIZ,r6,1b | |
140 | rsb | |
141 | /* rew: rewind the tape */ | |
142 | rew: | |
143 | clrl mtapa(fp) /* current position */ | |
144 | movw $TM_REW+TMDENS+GO,TMCS(%rTM) | |
145 | rsb | |
146 | /* rrec: read 1 block from mag tape into page (r0) */ | |
147 | rrec: | |
148 | /* pushl r0; movzbl $'r,r0; bsbw putc; movl (sp)+,r0; */ | |
149 | jsb tmquiet | |
150 | movw $-BLKSIZ,TMBC(%rTM) | |
151 | bisl3 $MRV|MR_BDP1,r0,UBA_MAP(%rUBA) | |
152 | movw $0,TMBA(%rTM) | |
153 | movw $TM_RCOM+TMDENS+GO,TMCS(%rTM) | |
154 | jsb tmquiet | |
155 | bisl2 $BNE,UBA_DPR1(%rUBA) | |
156 | tstw TMER(%rTM) | |
157 | jgeq 2f | |
158 | mnegw $1,TMBC(%rTM) | |
159 | movw $TM_SREV+TMDENS+GO,TMCS(%rTM) | |
160 | jmp rrec | |
161 | 2: | |
162 | incl r0 /* next page no. */ | |
163 | incl mtapa(fp) /* mag tape block position */ | |
164 | rsb | |
165 | getc: | |
166 | mfpr $RXCS,r0 | |
167 | bbc $RXCS_pd,r0,getc /* receiver ready ? */ | |
168 | mfpr $RXDB,r0 | |
169 | extzv $0,$7,r0,r0 | |
170 | cmpb r0,$015 | |
171 | bneq putc | |
172 | bsbb putc | |
173 | movb $0,r0 | |
174 | bsbb putc | |
175 | movb $012,r0 | |
176 | putc: | |
177 | mfpr $TXCS,r2 | |
178 | bbc $TXCS_pr,r2,putc /* transmitter ready ? */ | |
179 | extzv $0,$7,r0,r0 | |
180 | mtpr r0,$TXDB | |
181 | rsb | |
182 | tmquiet: | |
183 | movw TMCS(%rTM),r2 | |
184 | bbc $TM_crdy,r2,tmquiet | |
185 | 1: | |
186 | movw TMER(%rTM),r2 | |
187 | blbc r2,1b /* low bit == TUR */ | |
188 | bbs $TM_gapsd,r2,1b | |
189 | rsb | |
190 | end: |