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.s 7.1 (Berkeley) 6/5/86" */ 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:
Defined functions
|
Last modified: 1986-06-05
Generated: 2016-12-26 |
Generated by src2html V0.67
page hit count: 1025 |
|