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: /* "@(#)mtboot.s 7.1 (Berkeley) 6/5/86" */ 8: 9: /* 10: * VAX tape boot block for distribution tapes 11: * works on massbys tu78 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: * Based on similar driver for tm03 formatter. 18: * Local modifications by Jeffrey R. Schwab June, 1982 19: * Purdue University Computing Center 20: */ 21: .set RELOC,0x70000 22: /* a.out defines */ 23: .set HDRSIZ,040 /* size of file header for VAX */ 24: .set MAGIC,0410 /* file type id in header */ 25: .set TSIZ,4 /* text size */ 26: .set DSIZ,8 /* data size */ 27: .set BSIZ,12 /* bss size */ 28: .set TENT,024 /* task header entry loc */ 29: /* tp directory definitions */ 30: .set FILSIZ,38 /* tp direc offset for file size */ 31: .set BNUM,44 /* tp dir offset for start block no. */ 32: .set ENTSIZ,64 /* size of 1 TP dir entry, bytes */ 33: .set PTHSIZ,32 /* size of TP path name, bytes */ 34: .set BLKSIZ,512 /* tape block size, bytes */ 35: .set NUMDIR,24 /* no. of dir blocks on tape */ 36: .set ENTBLK,8 /* no. of dir entries per tape block */ 37: /* processor registers and bits */ 38: .set RXCS,32 39: .set RXDB,33 40: .set TXCS,34 41: .set TXDB,35 42: .set RXCS_DONE,0x80 43: .set TXCS_RDY,0x80 44: .set TXCS_pr,7 /* bit position of TXCS ready bit */ 45: .set RXCS_pd,7 /* bit position of RXCS done bit */ 46: /* MBA registers */ 47: .set MBA_CSR,0 /* configuration and status register */ 48: .set MBA_CR,4 /* MBA control reg */ 49: .set MBA_SR,8 /* MBA status reg */ 50: .set MBA_VAR,12 /* MBA virt addr reg */ 51: .set MBA_BCR,16 /* MBA byte count reg */ 52: .set MBA_MAP,0x800 /* start of MBA map reg's */ 53: .set MRV,0x80000000 54: .set MBA_bsy,31 /* massbus busy */ 55: /* TU78 mba registers */ 56: .set MTCS,0 /* MT data transfer control reg */ 57: .set MTER,4 /* data transfer error status reg */ 58: .set MTRC,8 /* record count */ 59: .set MTAS,16 /* attention summary */ 60: .set MTBC,20 /* byte count */ 61: .set MTNER,44 /* non data transfer error status reg */ 62: .set MTNCS,48 /* non data transfer control reg */ 63: .set MTID,68 /* internal data reg */ 64: /* MT commands */ 65: .set GO,1 /* GO bit */ 66: .set MT_REW,6 /* rewind, on-line */ 67: .set MT_RCOM,070 /* read forward */ 68: /* MT bits */ 69: .set MT_rdy,15 /* controller ready */ 70: .set MT_rec,2 /* bit for single record count */ 71: .set MT_rcnt,4 /* record count for single record (shifted) */ 72: .set MT_erc,0xffffffc0 /* error code mask */ 73: .set MT_done,1 /* proper completion code */ 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 rMBA,r10 80: .set rMT,r11 81: 82: /* initialization */ 83: init: 84: mull2 $0x80,%rMT 85: addl2 $0x400,%rMT 86: addl2 %rMBA,%rMT 87: movl $RELOC,fp /* core loc to which to move this program */ 88: addl3 $name,fp,sp /* set stack pointer, leaving room for locals */ 89: clrl r0 90: 1: 91: movc3 $end,(r0),(fp) /* move boot up to relocated position */ 92: jmp start+RELOC 93: start: 94: movl $1,MBA_CR(%rMBA) /* MBA init */ 95: 1: 96: movl MTID(%rMT),r2 /* wait for tape controller to ready */ 97: bbc $MT_rdy,r2,1b /* after massbus init */ 98: bsbw rew /* rewind input tape */ 99: movab name(fp),r4 /* start of filename storage */ 100: movzbl $'=,r0 /* prompt character */ 101: bsbw putc /* output char to main console */ 102: /* read in a file name */ 103: movl r4,r1 /* loc at which to store file name */ 104: nxtc: 105: bsbw getc /* get input char's in file name */ 106: cmpb r0,$012 /* terminator ? */ 107: beql nullc 108: movb r0,(r1)+ 109: brb nxtc 110: nullc: 111: subl3 r4,r1,r9 /* size of path name */ 112: beql start /* dumb operator */ 113: clrb (r1)+ 114: incl r9 115: /* user-specified TP filename has been stored at name(fp) */ 116: /* read in entire tp directory contents into low core */ 117: dirred: 118: movl $8,tapa(fp) /* tp directory starts at block 8 */ 119: movl $(NUMDIR*BLKSIZ),r6 /* no. bytes in total dir */ 120: bsbw taper /* read no. bytes indicated */ 121: /* search entire directory for user-specified file name */ 122: clrl r5 /* dir buff loc = 0 */ 123: nxtdir: 124: cmpc3 r9,(r5),(r4) /* see if dir entry matches filename */ 125: beql fndfil /* found match */ 126: acbl $NUMDIR*BLKSIZ-1,$ENTSIZ,r5,nxtdir 127: /* see if done with tp dir */ 128: brw start /* entry not in directory; start over */ 129: /* found desired tp dir entry */ 130: fndfil: 131: movzwl BNUM(r5),tapa(fp) /* start block no., 2 bytes */ 132: addl2 $7,tapa(fp) /* skip 7 boot blocks */ 133: movzwl FILSIZ(r5),r6 /* low 2 bytes file size */ 134: insv FILSIZ-1(r5),$16,$8,r6 /* file size, high byte */ 135: cmpl r6,$RELOC-512 /* check if file fits below stack */ 136: blss filok /* file o.k. */ 137: brw start /* file too large */ 138: /* time to read in desired file from tape */ 139: filok: 140: movl r6,r7 /* save r6 */ 141: bsbb taper 142: bsbw rew 143: /* clear core */ 144: subl3 r7,$RELOC-4,r0 /* no. bytes to clear */ 145: 1: 146: clrb (r7)+ 147: sobgtr r0,1b 148: /* time to jump to start of file & execute */ 149: addl3 $20,fp,ap 150: clrl r5 151: calls $0,(r5) 152: brw start 153: /* taper: movcTAPE (r6),tapa(fp),0 */ 154: rew2: 155: bsbb rew /* beginning of tape */ 156: taper0: 157: bsbb rrec /* advance 1 block; never want blk0 */ 158: taper: 159: clrl r0 /* page no. */ 160: cmpl mtapa(fp),tapa(fp) /* current position .vs. desired */ 161: bgtr rew2 162: blss taper0 163: 1: 164: bsbb rrec 165: acbl $1,$-BLKSIZ,r6,1b 166: rsb 167: /* rew: rewind the tape */ 168: rew: 169: clrl mtapa(fp) /* current position */ 170: movl MTNER(%rMT),r2 /* read non-data status */ 171: movl MTAS(%rMT),MTAS(%rMT) /* and clear any attention bits */ 172: movl $MT_REW+GO,MTNCS(%rMT) /* rewind command and go bit */ 173: 1: 174: movl MTAS(%rMT),r2 /* check attention bits */ 175: beql 1b /* loop if attention not yet set */ 176: movl MTNER(%rMT),r2 /* read non-data status */ 177: movl MTAS(%rMT),MTAS(%rMT) /* and clear any attention bits */ 178: bicl2 $MT_erc,r2 /* isolate error condition */ 179: subl2 $MT_done,r2 /* check with completion condition */ 180: bneq 1b /* wait for completion attention */ 181: rsb 182: /* rrec: read 1 block from mag tape into page (r0) */ 183: rrec: 184: /* pushl r0; movzbl $'r,r0; bsbw putc; movl (sp)+,r0; */ 185: movl MTNER(%rMT),r2 /* read non-data status */ 186: movl MTAS(%rMT),MTAS(%rMT) /* and clear any attention bits */ 187: movl $-BLKSIZ,MBA_BCR(%rMBA) 188: bisl3 $MRV,r0,MBA_MAP(%rMBA) 189: clrl MBA_VAR(%rMBA) 190: movl $BLKSIZ,MTBC(%rMT) /* set byte count */ 191: bisl2 $MT_rcnt,MTRC(%rMT) /* set record count */ 192: movl $MT_RCOM+GO,MTCS(%rMT) /* load read command */ 193: 1: 194: movl MBA_SR(%rMBA),r2 /* load mba status reg */ 195: bbs $MBA_bsy,r2,1b /* wait for mba to go non-busy */ 196: movl MTRC(%rMT),r2 /* fetch record count */ 197: bbs $MT_rec,r2,rrec /* retry read if we did not read a record */ 198: movl MTER(%rMT),r2 /* load data transfer error status */ 199: bicl2 $MT_erc,r2 /* isolate status value */ 200: subl2 $MT_done,r2 /* compare with successful read */ 201: bneq rrec /* load to try read again */ 202: 203: incl r0 /* next page no. */ 204: incl mtapa(fp) /* mag tape block position */ 205: rsb 206: getc: 207: mfpr $RXCS,r0 208: bbc $RXCS_pd,r0,getc /* receiver ready ? */ 209: mfpr $RXDB,r0 210: extzv $0,$7,r0,r0 211: cmpb r0,$015 212: bneq putc 213: bsbb putc 214: movb $0,r0 215: bsbb putc 216: movb $012,r0 217: putc: 218: mfpr $TXCS,r2 219: bbc $TXCS_pr,r2,putc /* transmitter ready ? */ 220: extzv $0,$7,r0,r0 221: mtpr r0,$TXDB 222: rsb 223: end:
Defined functions
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Last modified: 1986-06-05
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