Commit | Line | Data |
---|---|---|
2afab629 SL |
1 | /* utboot.c 4.1 83/02/16 */ |
2 | ||
3 | /* | |
4 | * VAX tape boot block for distribution tapes | |
5 | * works on unibus tm03 | |
6 | * | |
7 | * reads a program from a tp directory on a tape and executes it | |
8 | * program must be stripped of the header and is loaded ``bits as is'' | |
9 | * you can return to this loader via ``ret'' as you are called ``calls $0,ent'' | |
10 | */ | |
11 | .set RELOC,0x70000 | |
12 | /* a.out defines */ | |
13 | .set HDRSIZ,040 /* size of file header for VAX */ | |
14 | .set MAGIC,0410 /* file type id in header */ | |
15 | .set TSIZ,4 /* text size */ | |
16 | .set DSIZ,8 /* data size */ | |
17 | .set BSIZ,12 /* bss size */ | |
18 | .set TENT,024 /* task header entry loc */ | |
19 | /* tp directory definitions */ | |
20 | .set FILSIZ,38 /* tp direc offset for file size */ | |
21 | .set BNUM,44 /* tp dir offset for start block no. */ | |
22 | .set ENTSIZ,64 /* size of 1 TP dir entry, bytes */ | |
23 | .set PTHSIZ,32 /* size of TP path name, bytes */ | |
24 | .set BLKSIZ,512 /* tape block size, bytes */ | |
25 | .set NUMDIR,24 /* no. of dir blocks on tape */ | |
26 | .set ENTBLK,8 /* no. of dir entries per tape block */ | |
27 | /* processor registers and bits */ | |
28 | .set RXCS,32 | |
29 | .set RXDB,33 | |
30 | .set TXCS,34 | |
31 | .set TXDB,35 | |
32 | .set RXCS_DONE,0x80 | |
33 | .set TXCS_RDY,0x80 | |
34 | .set TXCS_pr,7 /* bit position of TXCS ready bit */ | |
35 | .set RXCS_pd,7 /* bit position of RXCS done bit */ | |
36 | /* UBA registers */ | |
37 | .set UBA_DPR1,68 | |
38 | .set UBA_MAP,2048 | |
39 | .set BNE,0x80000000 | |
40 | .set MRV,0x80000000 | |
41 | .set MR_BDP1,0x200000 | |
42 | ||
43 | /* UT UBA registers */ | |
44 | .set UTCS1,0 | |
45 | .set UTWC,02 | |
46 | .set UTBA,04 | |
47 | .set UTFC,06 | |
48 | .set UTCS2,010 | |
49 | .set UTDS,012 | |
50 | .set UTER,014 | |
51 | .set UTAS,016 | |
52 | .set UTCK,020 | |
53 | .set UTDB,022 | |
54 | .set UTMR,024 | |
55 | .set UTDT,026 | |
56 | .set UTSN,030 | |
57 | .set UTTC,032 | |
58 | ||
59 | /* UT commands and bits */ | |
60 | .set GO,01 | |
61 | .set UT_REW,06 | |
62 | .set UT_RCOM,070 | |
63 | .set UT_SREV,032 | |
64 | .set UT_DCLR,010 | |
65 | .set UT_crdy,0200 | |
66 | .set UT_gapsd,020000 /* aka "positioning in progress" */ | |
67 | .set UTDENS,0 /* 1600 bpi */ | |
68 | /* local stack variables */ | |
69 | .set tapa,-4 /* desired tape addr */ | |
70 | .set mtapa,-8 /* current tape addr */ | |
71 | .set name,-8-PTHSIZ /* operator-typed file name */ | |
72 | /* register usage */ | |
73 | .set rUBA,r10 | |
74 | .set rUT,r11 | |
75 | /* ===== */ | |
76 | ||
77 | /* initialization */ | |
78 | init: | |
79 | movl $RELOC,fp /* core loc to which to move this program */ | |
80 | addl3 $name,fp,sp /* set stack pointer; leave room for locals */ | |
81 | clrl r0 | |
82 | 1: | |
83 | movc3 $end,(r0),(fp) /* move boot up to relocated position */ | |
84 | jmp start+RELOC | |
85 | start: | |
86 | bsbw rew /* rewind input tape */ | |
87 | movab name(fp),r4 /* start of filename storage */ | |
88 | movzbl $'=,r0 /* prompt character */ | |
89 | bsbw putc /* output char to main console */ | |
90 | /* read in a file name */ | |
91 | movl r4,r1 /* loc at which to store file name */ | |
92 | nxtc: | |
93 | bsbw getc /* get input char's in file name */ | |
94 | cmpb r0,$012 /* terminator ? */ | |
95 | beql nullc | |
96 | movb r0,(r1)+ | |
97 | brb nxtc | |
98 | nullc: | |
99 | subl3 r4,r1,r9 /* size of path name */ | |
100 | beql start /* dumb operator */ | |
101 | clrb (r1)+ | |
102 | incl r9 | |
103 | /* user-specified TP filename has been stored at name(fp) */ | |
104 | /* read in entire tp directory contents into low core */ | |
105 | dirred: | |
106 | movl $8,tapa(fp) /* tp directory starts at block 8 */ | |
107 | movl $(NUMDIR*BLKSIZ),r6 /* no. bytes in total dir */ | |
108 | bsbw taper /* read no. bytes indicated */ | |
109 | /* search entire directory for user-specified file name */ | |
110 | clrl r5 /* dir buff loc = 0 */ | |
111 | nxtdir: | |
112 | cmpc3 r9,(r5),(r4) /* see if dir entry matches filename */ | |
113 | beql fndfil /* found match */ | |
114 | acbl $NUMDIR*BLKSIZ-1,$ENTSIZ,r5,nxtdir | |
115 | /* see if done with tp dir */ | |
116 | brw start /* entry not in directory; start over */ | |
117 | /* found desired tp dir entry */ | |
118 | fndfil: | |
119 | movzwl BNUM(r5),tapa(fp) /* start block no., 2 bytes */ | |
120 | addl2 $7,tapa(fp) /* skip 7 boot blocks */ | |
121 | movzwl FILSIZ(r5),r6 /* low 2 bytes file size */ | |
122 | insv FILSIZ-1(r5),$16,$8,r6 /* file size, high byte */ | |
123 | cmpl r6,$RELOC-512 /* check if file fits below stack */ | |
124 | blss filok /* file o.k. */ | |
125 | brw start /* file too large */ | |
126 | /* time to read in desired file from tape */ | |
127 | filok: | |
128 | movl r6,r7 /* save r6 */ | |
129 | bsbb taper | |
130 | bsbw rew | |
131 | /* clear core */ | |
132 | subl3 r7,$RELOC-4,r0 /* no. bytes to clear */ | |
133 | 1: | |
134 | clrb (r7)+ | |
135 | sobgtr r0,1b | |
136 | /* time to jump to start of file & execute */ | |
137 | addl3 $20,fp,ap | |
138 | clrl r5 | |
139 | calls $0,(r5) | |
140 | brw start | |
141 | /* taper: movcTAPE (r6),tapa(fp),0 */ | |
142 | rew2: | |
143 | bsbb rew /* beginning of tape */ | |
144 | taper0: | |
145 | bsbb rrec /* advance 1 block; never want blk 0 */ | |
146 | taper: | |
147 | clrl r0 /* page no. */ | |
148 | cmpl mtapa(fp),tapa(fp) /* current position .vs. desired */ | |
149 | bgtr rew2 | |
150 | blss taper0 | |
151 | 1: | |
152 | bsbb rrec | |
153 | acbl $1,$-BLKSIZ,r6,1b | |
154 | rsb | |
155 | /* rew: rewind the tape */ | |
156 | rew: | |
157 | clrl mtapa(fp) /* current position */ | |
158 | movw $UTDENS,UTTC(%rUT) /* select drive */ | |
159 | movw $UT_REW+GO,UTCS1(%rUT) | |
160 | rsb | |
161 | /* rrec: read 1 block from mag tape into page (r0) */ | |
162 | rrec: | |
163 | /* pushl r0; movzbl $'r,r0; bsbw putc; movl (sp)+,r0; */ | |
164 | jsb xtquiet | |
165 | movw $-BLKSIZ,UTFC(%rUT) | |
166 | movw $-256,UTWC(%rUT) /* !!!!!!!!!!!!!! */ | |
167 | bisl3 $MRV|MR_BDP1,r0,UBA_MAP(%rUBA) | |
168 | movw $0,UTBA(%rUT) | |
169 | movw $UTDENS,UTTC(%rUT) /* select drive */ | |
170 | movw $UT_RCOM+GO,UTCS1(%rUT) | |
171 | jsb xtquiet | |
172 | bisl2 $BNE,UBA_DPR1(%rUBA) | |
173 | tstw UTER(%rUT) | |
174 | jgeq 2f | |
175 | mnegw $1,UTWC(%rUT) | |
176 | movw $UTDENS,UTTC(%rUT) /* select drive */ | |
177 | movw $UT_SREV+GO,UTCS1(%rUT) | |
178 | jmp rrec | |
179 | 2: | |
180 | incl r0 /* next page no. */ | |
181 | incl mtapa(fp) /* mag tape block position */ | |
182 | rsb | |
183 | getc: | |
184 | mfpr $RXCS,r0 | |
185 | bbc $RXCS_pd,r0,getc /* receiver ready ? */ | |
186 | mfpr $RXDB,r0 | |
187 | extzv $0,$7,r0,r0 | |
188 | cmpb r0,$015 | |
189 | bneq putc | |
190 | bsbb putc | |
191 | movb $0,r0 | |
192 | bsbb putc | |
193 | movb $012,r0 | |
194 | putc: | |
195 | mfpr $TXCS,r2 | |
196 | bbc $TXCS_pr,r2,putc /* transmitter ready ? */ | |
197 | extzv $0,$7,r0,r0 | |
198 | mtpr r0,$TXDB | |
199 | rsb | |
200 | xtquiet: | |
201 | movw UTCS1(%rUT),r2 | |
202 | bbc $UT_crdy,r2,xtquiet | |
203 | 1: | |
204 | movw UTDS(%rUT),r2 | |
205 | bbs $UT_gapsd,r2,1b | |
206 | rsb | |
207 | end: |