1 /* tmboot.c 6.1 83/07/29 */ 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 /* TM UBA registers */ 43 .set TMER,0 44 .set TMCS,2 45 .set TMBC,4 46 .set TMBA,6 47 /* TM commands and bits */ 48 .set GO,1 49 .set TM_REW,016 50 .set TM_RCOM,02 51 .set TM_SREV,012 52 .set TM_DCLR,010000 53 .set TM_crdy,7 54 .set TM_gapsd,3 55 .set TMDENS,0 /* 1600 bpi */ 56 /* local stack variables */ 57 .set tapa,-4 /* desired tape addr */ 58 .set mtapa,-8 /* current tape addr */ 59 .set name,-8-PTHSIZ /* operator-typed file name */ 60 /* register usage */ 61 .set rUBA,r10 62 .set rTM,r11 63 /* ===== */ 64 65 /* initialization */ 66 init: 67 movl $RELOC,fp /* core loc to which to move this program */ 68 addl3 $name,fp,sp /* set stack pointer; leave room for locals */ 69 clrl r0 70 1: 71 movc3 $end,(r0),(fp) /* move boot up to relocated position */ 72 jmp start+RELOC 73 start: 74 bsbw rew /* rewind input tape */ 75 movab name(fp),r4 /* start of filename storage */ 76 movzbl $'=,r0 /* prompt character */ 77 bsbw putc /* output char to main console */ 78 /* read in a file name */ 79 movl r4,r1 /* loc at which to store file name */ 80 nxtc: 81 bsbw getc /* get input char's in file name */ 82 cmpb r0,$012 /* terminator ? */ 83 beql nullc 84 movb r0,(r1)+ 85 brb nxtc 86 nullc: 87 subl3 r4,r1,r9 /* size of path name */ 88 beql start /* dumb operator */ 89 clrb (r1)+ 90 incl r9 91 /* user-specified TP filename has been stored at name(fp) */ 92 /* read in entire tp directory contents into low core */ 93 dirred: 94 movl $8,tapa(fp) /* tp directory starts at block 8 */ 95 movl $(NUMDIR*BLKSIZ),r6 /* no. bytes in total dir */ 96 bsbw taper /* read no. bytes indicated */ 97 /* search entire directory for user-specified file name */ 98 clrl r5 /* dir buff loc = 0 */ 99 nxtdir: 100 cmpc3 r9,(r5),(r4) /* see if dir entry matches filename */ 101 beql fndfil /* found match */ 102 acbl $NUMDIR*BLKSIZ-1,$ENTSIZ,r5,nxtdir 103 /* see if done with tp dir */ 104 brw start /* entry not in directory; start over */ 105 /* found desired tp dir entry */ 106 fndfil: 107 movzwl BNUM(r5),tapa(fp) /* start block no., 2 bytes */ 108 addl2 $7,tapa(fp) /* skip 7 boot blocks */ 109 movzwl FILSIZ(r5),r6 /* low 2 bytes file size */ 110 insv FILSIZ-1(r5),$16,$8,r6 /* file size, high byte */ 111 cmpl r6,$RELOC-512 /* check if file fits below stack */ 112 blss filok /* file o.k. */ 113 brw start /* file too large */ 114 /* time to read in desired file from tape */ 115 filok: 116 movl r6,r7 /* save r6 */ 117 bsbb taper 118 bsbw rew 119 /* clear core */ 120 subl3 r7,$RELOC-4,r0 /* no. bytes to clear */ 121 1: 122 clrb (r7)+ 123 sobgtr r0,1b 124 /* time to jump to start of file & execute */ 125 addl3 $20,fp,ap 126 clrl r5 127 calls $0,(r5) 128 brw start 129 /* taper: movcTAPE (r6),tapa(fp),0 */ 130 rew2: 131 bsbb rew /* beginning of tape */ 132 taper0: 133 bsbb rrec /* advance 1 block; never want blk 0 */ 134 taper: 135 clrl r0 /* page no. */ 136 cmpl mtapa(fp),tapa(fp) /* current position .vs. desired */ 137 bgtr rew2 138 blss taper0 139 1: 140 bsbb rrec 141 acbl $1,$-BLKSIZ,r6,1b 142 rsb 143 /* rew: rewind the tape */ 144 rew: 145 clrl mtapa(fp) /* current position */ 146 movw $TM_REW+TMDENS+GO,TMCS(%rTM) 147 rsb 148 /* rrec: read 1 block from mag tape into page (r0) */ 149 rrec: 150 /* pushl r0; movzbl $'r,r0; bsbw putc; movl (sp)+,r0; */ 151 jsb tmquiet 152 movw $-BLKSIZ,TMBC(%rTM) 153 bisl3 $MRV|MR_BDP1,r0,UBA_MAP(%rUBA) 154 movw $0,TMBA(%rTM) 155 movw $TM_RCOM+TMDENS+GO,TMCS(%rTM) 156 jsb tmquiet 157 bisl2 $BNE,UBA_DPR1(%rUBA) 158 tstw TMER(%rTM) 159 jgeq 2f 160 mnegw $1,TMBC(%rTM) 161 movw $TM_SREV+TMDENS+GO,TMCS(%rTM) 162 jmp rrec 163 2: 164 incl r0 /* next page no. */ 165 incl mtapa(fp) /* mag tape block position */ 166 rsb 167 getc: 168 mfpr $RXCS,r0 169 bbc $RXCS_pd,r0,getc /* receiver ready ? */ 170 mfpr $RXDB,r0 171 extzv $0,$7,r0,r0 172 cmpb r0,$015 173 bneq putc 174 bsbb putc 175 movb $0,r0 176 bsbb putc 177 movb $012,r0 178 putc: 179 mfpr $TXCS,r2 180 bbc $TXCS_pr,r2,putc /* transmitter ready ? */ 181 extzv $0,$7,r0,r0 182 mtpr r0,$TXDB 183 rsb 184 tmquiet: 185 movw TMCS(%rTM),r2 186 bbc $TM_crdy,r2,tmquiet 187 1: 188 movw TMER(%rTM),r2 189 blbc r2,1b /* low bit == TUR */ 190 bbs $TM_gapsd,r2,1b 191 rsb 192 end: 193