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 /* "@(#)htboot.c 7.1 (Berkeley) 06/05/86" */ 8 9 10 /* 11 * VAX tape boot block for distribution tapes 12 * works on massbus tu10/te16/tu45/tu77 13 * 14 * reads a program from a tp directory on a tape and executes it 15 * program must be stripped of the header and is loaded ``bits as is'' 16 * you can return to this loader via ``ret'' as you are called ``calls $0,ent'' 17 */ 18 .set RELOC,0x70000 19 /* a.out defines */ 20 .set HDRSIZ,040 /* size of file header for VAX */ 21 .set MAGIC,0410 /* file type id in header */ 22 .set TSIZ,4 /* text size */ 23 .set DSIZ,8 /* data size */ 24 .set BSIZ,12 /* bss size */ 25 .set TENT,024 /* task header entry loc */ 26 /* tp directory definitions */ 27 .set FILSIZ,38 /* tp direc offset for file size */ 28 .set BNUM,44 /* tp dir offset for start block no. */ 29 .set ENTSIZ,64 /* size of 1 TP dir entry, bytes */ 30 .set PTHSIZ,32 /* size of TP path name, bytes */ 31 .set BLKSIZ,512 /* tape block size, bytes */ 32 .set NUMDIR,24 /* no. of dir blocks on tape */ 33 .set ENTBLK,8 /* no. of dir entries per tape block */ 34 /* processor registers and bits */ 35 .set RXCS,32 36 .set RXDB,33 37 .set TXCS,34 38 .set TXDB,35 39 .set RXCS_DONE,0x80 40 .set TXCS_RDY,0x80 41 .set TXCS_pr,7 /* bit position of TXCS ready bit */ 42 .set RXCS_pd,7 /* bit position of RXCS done bit */ 43 /* MBA registers */ 44 .set MBA_CSR,0 /* configuration and status register */ 45 .set MBA_CR,4 /* MBA control reg */ 46 .set MBA_SR,8 /* MBA status reg */ 47 .set MBA_VAR,12 /* MBA virt addr reg */ 48 .set MBA_BCR,16 /* MBA byte count reg */ 49 .set MBA_MAP,0x800 /* start of MBA map reg's */ 50 .set MRV,0x80000000 51 /* TE16/TU45/TU77 mba registers */ 52 .set HTCS1,0 /* HT control 1 reg */ 53 .set HTDS,4 /* status reg */ 54 .set HTER,8 /* error reg */ 55 .set HTAS,16 /* attention summary */ 56 .set HTFC,20 /* frame count */ 57 .set HTTC,36 /* HT tape control */ 58 /* HT commands */ 59 .set GO,1 /* GO bit */ 60 .set HT_REW,6 /* rewind, on-line */ 61 .set HT_DCLR,010 /* drive clear */ 62 .set HT_SREV,032 /* space reverse */ 63 .set HT_RCOM,070 /* read forward */ 64 /* HT bits */ 65 .set ERR,040000 /* composite error bit in status reg */ 66 .set TCHAR,012300 /* unit 0, odd parity, PDP11, 1600 BPI NRZ, */ 67 /* abort on error - for tape controller */ 68 .set DRDY,0200 /* HT/drive ready in status reg */ 69 .set HT_pd,7 /* bit position of HT DRDY bit */ 70 .set HT_pe,14 /* bit position of HT ERROR bit */ 71 /* local stack variables */ 72 .set tapa,-4 /* desired tape addr */ 73 .set mtapa,-8 /* current tape addr */ 74 .set name,-8-PTHSIZ /* operator-typed file name */ 75 /* register usage */ 76 .set rMBA,r10 77 .set rHT,r11 78 79 /* initialization */ 80 init: 81 mull2 $0x80,%rHT 82 addl2 $0x400,%rHT 83 addl2 %rMBA,%rHT 84 movl $RELOC,fp /* core loc to which to move this program */ 85 addl3 $name,fp,sp /* set stack pointer, leaving room for locals */ 86 clrl r0 87 1: 88 movc3 $end,(r0),(fp) /* move boot up to relocated position */ 89 jmp start+RELOC 90 start: 91 movl $1,MBA_CR(%rMBA) /* MBA init */ 92 movl $TCHAR,HTTC(%rHT) /* drive no., etc. */ 93 movl $HT_DCLR+GO,HTCS1(%rHT) /* drive clear */ 94 bsbw rew /* rewind input tape */ 95 movab name(fp),r4 /* start of filename storage */ 96 movzbl $'=,r0 /* prompt character */ 97 bsbw putc /* output char to main console */ 98 /* read in a file name */ 99 movl r4,r1 /* loc at which to store file name */ 100 nxtc: 101 bsbw getc /* get input char's in file name */ 102 cmpb r0,$012 /* terminator ? */ 103 beql nullc 104 movb r0,(r1)+ 105 brb nxtc 106 nullc: 107 subl3 r4,r1,r9 /* size of path name */ 108 beql start /* dumb operator */ 109 clrb (r1)+ 110 incl r9 111 /* user-specified TP filename has been stored at name(fp) */ 112 /* read in entire tp directory contents into low core */ 113 dirred: 114 movl $8,tapa(fp) /* tp directory starts at block 8 */ 115 movl $(NUMDIR*BLKSIZ),r6 /* no. bytes in total dir */ 116 bsbw taper /* read no. bytes indicated */ 117 /* search entire directory for user-specified file name */ 118 clrl r5 /* dir buff loc = 0 */ 119 nxtdir: 120 cmpc3 r9,(r5),(r4) /* see if dir entry matches filename */ 121 beql fndfil /* found match */ 122 acbl $NUMDIR*BLKSIZ-1,$ENTSIZ,r5,nxtdir 123 /* see if done with tp dir */ 124 brw start /* entry not in directory; start over */ 125 /* found desired tp dir entry */ 126 fndfil: 127 movzwl BNUM(r5),tapa(fp) /* start block no., 2 bytes */ 128 addl2 $7,tapa(fp) /* skip 7 boot blocks */ 129 movzwl FILSIZ(r5),r6 /* low 2 bytes file size */ 130 insv FILSIZ-1(r5),$16,$8,r6 /* file size, high byte */ 131 cmpl r6,$RELOC-512 /* check if file fits below stack */ 132 blss filok /* file o.k. */ 133 brw start /* file too large */ 134 /* time to read in desired file from tape */ 135 filok: 136 movl r6,r7 /* save r6 */ 137 bsbb taper 138 bsbw rew 139 /* clear core */ 140 subl3 r7,$RELOC-4,r0 /* no. bytes to clear */ 141 1: 142 clrb (r7)+ 143 sobgtr r0,1b 144 /* time to jump to start of file & execute */ 145 addl3 $20,fp,ap 146 clrl r5 147 calls $0,(r5) 148 brw start 149 /* taper: movcTAPE (r6),tapa(fp),0 */ 150 rew2: 151 bsbb rew /* beginning of tape */ 152 taper0: 153 bsbb rrec /* advance 1 block; never want blk0 */ 154 taper: 155 clrl r0 /* page no. */ 156 cmpl mtapa(fp),tapa(fp) /* current position .vs. desired */ 157 bgtr rew2 158 blss taper0 159 1: 160 bsbb rrec 161 acbl $1,$-BLKSIZ,r6,1b 162 rsb 163 /* rew: rewind the tape */ 164 rew: 165 clrl mtapa(fp) /* current position */ 166 movl $HT_REW+GO,HTCS1(%rHT) /* rewind */ 167 rsb 168 /* rrec: read 1 block from mag tape into page (r0) */ 169 rrec: 170 /* pushl r0; movzbl $'r,r0; bsbw putc; movl (sp)+,r0; */ 171 movl HTDS(%rHT),r2 172 bbc $HT_pd,r2,rrec /* HT & drive ready ? */ 173 movl $-BLKSIZ,MBA_BCR(%rMBA) 174 bisl3 $MRV,r0,MBA_MAP(%rMBA) 175 clrl MBA_VAR(%rMBA) 176 movl $HT_RCOM+GO,HTCS1(%rHT) /* read forward */ 177 1: 178 movl HTDS(%rHT),r2 179 bbc $HT_pd,r2,1b 180 movl HTER(%rHT),r2 181 bbc $HT_pe,r2,2f /* any read errors ? */ 182 clrl HTDS(%rHT) /* clear status - try to recover */ 183 mnegl $1,HTFC(%rHT) /* frame count for backspace */ 184 movl $HT_SREV+GO,HTCS1(%rHT) /* space reverse */ 185 brb rrec 186 2: 187 incl r0 /* next page no. */ 188 incl mtapa(fp) /* mag tape block position */ 189 rsb 190 getc: 191 mfpr $RXCS,r0 192 bbc $RXCS_pd,r0,getc /* receiver ready ? */ 193 mfpr $RXDB,r0 194 extzv $0,$7,r0,r0 195 cmpb r0,$015 196 bneq putc 197 bsbb putc 198 movb $0,r0 199 bsbb putc 200 movb $012,r0 201 putc: 202 mfpr $TXCS,r2 203 bbc $TXCS_pr,r2,putc /* transmitter ready ? */ 204 extzv $0,$7,r0,r0 205 mtpr r0,$TXDB 206 rsb 207 end: 208