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 /* "@(#)tmboot.c 7.1 (Berkeley) 06/05/86" */ 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 /* TM UBA registers */ 49 .set TMER,0 50 .set TMCS,2 51 .set TMBC,4 52 .set TMBA,6 53 /* TM commands and bits */ 54 .set GO,1 55 .set TM_REW,016 56 .set TM_RCOM,02 57 .set TM_SREV,012 58 .set TM_DCLR,010000 59 .set TM_crdy,7 60 .set TM_gapsd,3 61 .set TMDENS,0 /* 1600 bpi */ 62 /* local stack variables */ 63 .set tapa,-4 /* desired tape addr */ 64 .set mtapa,-8 /* current tape addr */ 65 .set name,-8-PTHSIZ /* operator-typed file name */ 66 /* register usage */ 67 .set rUBA,r10 68 .set rTM,r11 69 /* ===== */ 70 71 /* initialization */ 72 init: 73 movl $RELOC,fp /* core loc to which to move this program */ 74 addl3 $name,fp,sp /* set stack pointer; leave room for locals */ 75 clrl r0 76 1: 77 movc3 $end,(r0),(fp) /* move boot up to relocated position */ 78 jmp start+RELOC 79 start: 80 bsbw rew /* rewind input tape */ 81 movab name(fp),r4 /* start of filename storage */ 82 movzbl $'=,r0 /* prompt character */ 83 bsbw putc /* output char to main console */ 84 /* read in a file name */ 85 movl r4,r1 /* loc at which to store file name */ 86 nxtc: 87 bsbw getc /* get input char's in file name */ 88 cmpb r0,$012 /* terminator ? */ 89 beql nullc 90 movb r0,(r1)+ 91 brb nxtc 92 nullc: 93 subl3 r4,r1,r9 /* size of path name */ 94 beql start /* dumb operator */ 95 clrb (r1)+ 96 incl r9 97 /* user-specified TP filename has been stored at name(fp) */ 98 /* read in entire tp directory contents into low core */ 99 dirred: 100 movl $8,tapa(fp) /* tp directory starts at block 8 */ 101 movl $(NUMDIR*BLKSIZ),r6 /* no. bytes in total dir */ 102 bsbw taper /* read no. bytes indicated */ 103 /* search entire directory for user-specified file name */ 104 clrl r5 /* dir buff loc = 0 */ 105 nxtdir: 106 cmpc3 r9,(r5),(r4) /* see if dir entry matches filename */ 107 beql fndfil /* found match */ 108 acbl $NUMDIR*BLKSIZ-1,$ENTSIZ,r5,nxtdir 109 /* see if done with tp dir */ 110 brw start /* entry not in directory; start over */ 111 /* found desired tp dir entry */ 112 fndfil: 113 movzwl BNUM(r5),tapa(fp) /* start block no., 2 bytes */ 114 addl2 $7,tapa(fp) /* skip 7 boot blocks */ 115 movzwl FILSIZ(r5),r6 /* low 2 bytes file size */ 116 insv FILSIZ-1(r5),$16,$8,r6 /* file size, high byte */ 117 cmpl r6,$RELOC-512 /* check if file fits below stack */ 118 blss filok /* file o.k. */ 119 brw start /* file too large */ 120 /* time to read in desired file from tape */ 121 filok: 122 movl r6,r7 /* save r6 */ 123 bsbb taper 124 bsbw rew 125 /* clear core */ 126 subl3 r7,$RELOC-4,r0 /* no. bytes to clear */ 127 1: 128 clrb (r7)+ 129 sobgtr r0,1b 130 /* time to jump to start of file & execute */ 131 addl3 $20,fp,ap 132 clrl r5 133 calls $0,(r5) 134 brw start 135 /* taper: movcTAPE (r6),tapa(fp),0 */ 136 rew2: 137 bsbb rew /* beginning of tape */ 138 taper0: 139 bsbb rrec /* advance 1 block; never want blk 0 */ 140 taper: 141 clrl r0 /* page no. */ 142 cmpl mtapa(fp),tapa(fp) /* current position .vs. desired */ 143 bgtr rew2 144 blss taper0 145 1: 146 bsbb rrec 147 acbl $1,$-BLKSIZ,r6,1b 148 rsb 149 /* rew: rewind the tape */ 150 rew: 151 clrl mtapa(fp) /* current position */ 152 movw $TM_REW+TMDENS+GO,TMCS(%rTM) 153 rsb 154 /* rrec: read 1 block from mag tape into page (r0) */ 155 rrec: 156 /* pushl r0; movzbl $'r,r0; bsbw putc; movl (sp)+,r0; */ 157 jsb tmquiet 158 movw $-BLKSIZ,TMBC(%rTM) 159 bisl3 $MRV|MR_BDP1,r0,UBA_MAP(%rUBA) 160 movw $0,TMBA(%rTM) 161 movw $TM_RCOM+TMDENS+GO,TMCS(%rTM) 162 jsb tmquiet 163 bisl2 $BNE,UBA_DPR1(%rUBA) 164 tstw TMER(%rTM) 165 jgeq 2f 166 mnegw $1,TMBC(%rTM) 167 movw $TM_SREV+TMDENS+GO,TMCS(%rTM) 168 jmp rrec 169 2: 170 incl r0 /* next page no. */ 171 incl mtapa(fp) /* mag tape block position */ 172 rsb 173 getc: 174 mfpr $RXCS,r0 175 bbc $RXCS_pd,r0,getc /* receiver ready ? */ 176 mfpr $RXDB,r0 177 extzv $0,$7,r0,r0 178 cmpb r0,$015 179 bneq putc 180 bsbb putc 181 movb $0,r0 182 bsbb putc 183 movb $012,r0 184 putc: 185 mfpr $TXCS,r2 186 bbc $TXCS_pr,r2,putc /* transmitter ready ? */ 187 extzv $0,$7,r0,r0 188 mtpr r0,$TXDB 189 rsb 190 tmquiet: 191 movw TMCS(%rTM),r2 192 bbc $TM_crdy,r2,tmquiet 193 1: 194 movw TMER(%rTM),r2 195 blbc r2,1b /* low bit == TUR */ 196 bbs $TM_gapsd,r2,1b 197 rsb 198 end: 199