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: /* "@(#)utboot.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: 49: /* UT UBA registers */ 50: .set UTCS1,0 51: .set UTWC,02 52: .set UTBA,04 53: .set UTFC,06 54: .set UTCS2,010 55: .set UTDS,012 56: .set UTER,014 57: .set UTAS,016 58: .set UTCC,020 59: .set UTDB,022 60: .set UTMR,024 61: .set UTDT,026 62: .set UTSN,030 63: .set UTTC,032 64: 65: /* UT commands and bits */ 66: .set GO,01 67: .set UT_REW,0x6 68: .set UT_RCOM,0x38 69: .set UT_SREV,0x1a 70: .set UT_DCLR,0x8 71: .set UT_crdy,7 /* bit pos. */ 72: .set UT_gapsd,13 /* bit; aka "positioning in progress" */ 73: .set UTDENS,0x4c0 /* 1600 bpi, PDP-11 format */ 74: /* local stack variables */ 75: .set tapa,-4 /* desired tape addr */ 76: .set mtapa,-8 /* current tape addr */ 77: .set name,-8-PTHSIZ /* operator-typed file name */ 78: /* register usage */ 79: .set rUBA,r10 80: .set rUT,r11 81: /* ===== */ 82: 83: /* initialization */ 84: init: 85: movl $RELOC,fp /* core loc to which to move this program */ 86: addl3 $name,fp,sp /* set stack pointer; leave room for locals */ 87: clrl r0 88: 1: 89: movc3 $end,(r0),(fp) /* move boot up to relocated position */ 90: jmp start+RELOC 91: start: 92: bsbw rew /* rewind input tape */ 93: movab name(fp),r4 /* start of filename storage */ 94: movzbl $'=,r0 /* prompt character */ 95: bsbw putc /* output char to main console */ 96: /* read in a file name */ 97: movl r4,r1 /* loc at which to store file name */ 98: nxtc: 99: bsbw getc /* get input char's in file name */ 100: cmpb r0,$012 /* terminator ? */ 101: beql nullc 102: movb r0,(r1)+ 103: brb nxtc 104: nullc: 105: subl3 r4,r1,r9 /* size of path name */ 106: beql start /* dumb operator */ 107: clrb (r1)+ 108: incl r9 109: /* user-specified TP filename has been stored at name(fp) */ 110: /* read in entire tp directory contents into low core */ 111: dirred: 112: movl $8,tapa(fp) /* tp directory starts at block 8 */ 113: movl $(NUMDIR*BLKSIZ),r6 /* no. bytes in total dir */ 114: bsbw taper /* read no. bytes indicated */ 115: /* search entire directory for user-specified file name */ 116: clrl r5 /* dir buff loc = 0 */ 117: nxtdir: 118: cmpc3 r9,(r5),(r4) /* see if dir entry matches filename */ 119: beql fndfil /* found match */ 120: acbl $NUMDIR*BLKSIZ-1,$ENTSIZ,r5,nxtdir 121: /* see if done with tp dir */ 122: brw start /* entry not in directory; start over */ 123: /* found desired tp dir entry */ 124: fndfil: 125: movzwl BNUM(r5),tapa(fp) /* start block no., 2 bytes */ 126: addl2 $7,tapa(fp) /* skip 7 boot blocks */ 127: movzwl FILSIZ(r5),r6 /* low 2 bytes file size */ 128: insv FILSIZ-1(r5),$16,$8,r6 /* file size, high byte */ 129: cmpl r6,$RELOC-512 /* check if file fits below stack */ 130: blss filok /* file o.k. */ 131: brw start /* file too large */ 132: /* time to read in desired file from tape */ 133: filok: 134: movl r6,r7 /* save r6 */ 135: bsbb taper 136: bsbw rew 137: /* clear core */ 138: subl3 r7,$RELOC-4,r0 /* no. bytes to clear */ 139: 1: 140: clrb (r7)+ 141: sobgtr r0,1b 142: /* time to jump to start of file & execute */ 143: addl3 $20,fp,ap 144: clrl r5 145: calls $0,(r5) 146: brw start 147: /* taper: movcTAPE (r6),tapa(fp),0 */ 148: rew2: 149: bsbb rew /* beginning of tape */ 150: taper0: 151: bsbb rrec /* advance 1 block; never want blk 0 */ 152: taper: 153: clrl r0 /* page no. */ 154: cmpl mtapa(fp),tapa(fp) /* current position .vs. desired */ 155: bgtr rew2 156: blss taper0 157: 1: 158: bsbb rrec 159: acbl $1,$-BLKSIZ,r6,1b 160: rsb 161: /* rew: rewind the tape */ 162: rew: 163: clrl mtapa(fp) /* current position */ 164: movw $UTDENS,UTTC(%rUT) /* select drive */ 165: movw $UT_REW+GO,UTCS1(%rUT) 166: rsb 167: /* rrec: read 1 block from mag tape into page (r0) */ 168: rrec: 169: /* pushl r0; movzbl $'r,r0; bsbw putc; movl (sp)+,r0; */ 170: jsb utquiet 171: movw $-BLKSIZ,UTFC(%rUT) 172: movw $-256,UTWC(%rUT) /* !!!!!!!!!!!!!! */ 173: bisl3 $MRV|MR_BDP1,r0,UBA_MAP(%rUBA) 174: movw $0,UTBA(%rUT) 175: movw $UTDENS,UTTC(%rUT) /* select drive */ 176: movw $UT_RCOM+GO,UTCS1(%rUT) 177: jsb utquiet 178: bisl2 $BNE,UBA_DPR1(%rUBA) 179: tstw UTER(%rUT) 180: jgeq 2f 181: mnegw $1,UTWC(%rUT) 182: movw $UTDENS,UTTC(%rUT) /* select drive */ 183: movw $UT_SREV+GO,UTCS1(%rUT) 184: jmp rrec 185: 2: 186: incl r0 /* next page no. */ 187: incl mtapa(fp) /* mag tape block position */ 188: rsb 189: getc: 190: mfpr $RXCS,r0 191: bbc $RXCS_pd,r0,getc /* receiver ready ? */ 192: mfpr $RXDB,r0 193: extzv $0,$7,r0,r0 194: cmpb r0,$015 195: bneq putc 196: bsbb putc 197: movb $0,r0 198: bsbb putc 199: movb $012,r0 200: putc: 201: mfpr $TXCS,r2 202: bbc $TXCS_pr,r2,putc /* transmitter ready ? */ 203: extzv $0,$7,r0,r0 204: mtpr r0,$TXDB 205: rsb 206: utquiet: 207: movw UTCS1(%rUT),r2 208: bbc $UT_crdy,r2,utquiet 209: 1: 210: movw UTDS(%rUT),r2 211: bbs $UT_gapsd,r2,1b 212: rsb 213: end:
Defined functions
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Last modified: 1986-06-05
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