1: MAJOR = 11. / major # from bdevsw[] 2: 3: / BR bootstrap. supports the 32 sec/trk, 19 trk/cyl EATON 1537/1711 4: / Controller and 1538A/B/C/D drive. 5: / 6: / 1995/05/31 - The unit number needs to go in bits 3-5 of bootdev 7: / because the partition number now goes into bits 0-2. 8: / 9: / disk boot program to load and transfer 10: / to a unix entry. 11: / for use with 1 KB byte blocks, CLSIZE is 2. 12: / NDIRIN is the number of direct inode addresses (currently 4) 13: / assembled size must be <= 512; if > 494, the 16-byte a.out header 14: / must be removed 15: 16: / options: none. all options of reading an alternate name or echoing to 17: / the keyboard had to be removed to make room for the 18: / code which understands the new directory structure on disc 19: 20: / constants: 21: CLSIZE = 2. / physical disk blocks per logical block 22: CLSHFT = 1. / shift to multiply by CLSIZE 23: BSIZE = 512.*CLSIZE / logical block size 24: INOSIZ = 64. / size of inode in bytes 25: NDIRIN = 4. / number of direct inode addresses 26: ADDROFF = 12. / offset of first address in inode 27: INOPB = BSIZE\/INOSIZ / inodes per logical block 28: INOFF = 31. / inode offset = (INOPB * (SUPERB+1)) - 1 29: PBSHFT = -4 / shift to divide by inodes per block 30: WC = -256.*CLSIZE / word count 31: 32: / The boot options and device are placed in the last SZFLAGS bytes 33: / at the end of core by the kernel for autobooting. 34: ENDCORE= 160000 / end of core, mem. management off 35: SZFLAGS= 6 / size of boot flags 36: BOOTOPTS= 2 / location of options, bytes below ENDCORE 37: BOOTDEV= 4 38: CHECKWORD= 6 39: 40: .. = ENDCORE-512.-SZFLAGS / save room for boot flags 41: 42: / entry is made by jsr pc,*$0 43: / so return can be rts pc 44: 45: / establish sp, copy 46: / program up to end of core. 47: 48: nop / These two lines must be present or DEC 49: br start / boot ROMs will refuse to run boot block! 50: start: 51: clr r0 / XXX - for Rome 11/70, boot card doesn't work 52: mov $176714,r1 / XXX - for Rome 11/70, boot card doesn't work 53: movb r0,unit+1 / save the unit in high byte (for brcs) 54: mov r1,csr / and csr from the ROMs (not base addr!) 55: mov $..,sp 56: mov sp,r1 57: clr r0 58: 1: 59: mov (r0)+,(r1)+ 60: cmp r1,$end 61: blo 1b 62: jmp *$2f 63: 64: / On error, restart from here. 65: restart: 66: clr r0 67: / clear core to make things clean 68: 2: 69: clr (r0)+ 70: cmp r0,sp 71: blo 2b 72: 73: / initialize controller 74: mov csr,r1 75: mov unit,brcs(r1) / clr addr extension bits, select unit 76: mov $32.,r0 / default # of sec/track 77: bit $2400,brae(r1) / is this a 22 sec/track drive 78: beq 9f 79: mov $22.,r0 80: 9: 81: mov $19.,r5 / default # of tracks/cyl 82: bit $1400,brae(r1) / is this a 5 tr/cy drive? 83: beq 9f / no - br 84: mov $5,r5 85: 9: 86: mov r0,sectors 87: mul r0,r5 / sectors/cyl 88: mov r5,seccyl 89: 90: mov $bootnm, r1 91: mov $2,r0 / ROOTINO 92: jsr pc,iget 93: clr r2 / offset 94: again: 95: jsr pc,readdir 96: beq restart / error - restart 97: mov 4(r0),r4 / dp->d_namlen 98: cmp r4,$bootlen / if (bootlen == dp->d_namlen) 99: bne again / nope, go try next entry 100: mov r0,r3 101: add $6,r3 / r3 = dp->d_name 102: mov r1,r5 / r5 = filename 103: 9: 104: cmpb (r3)+,(r5)+ 105: bne again / no match - go read next entry 106: sob r4,9b 107: mov (r0),r0 / r0 = dp->d_ino 108: jsr pc,iget / fetch boot's inode 109: br loadfile / 'boot'- go read it 110: 111: / get the inode specified in r0 112: iget: 113: add $INOFF,r0 114: mov r0,r5 115: ash $PBSHFT,r0 116: bic $!7777,r0 117: mov r0,dno 118: clr r0 119: jsr pc,rblk 120: bic $!17,r5 121: mov $INOSIZ,r0 122: mul r0,r5 123: add $buf,r5 124: mov $inod,r4 125: 1: 126: movb (r5)+,(r4)+ 127: sob r0,1b 128: rts pc 129: 130: readdir: 131: bit $BSIZE-1,r2 132: bne 1f 133: jsr pc,rmblk / read mapped block (bno) 134: br err / end of file branch 135: clr r2 / start at beginning of buf 136: 1: 137: mov $buf,r0 138: add r2,r0 / dp = buf+offset 139: add buf+2(r2),r2 / dp += dp->d_reclen 140: tst (r0) / dp->d_ino == 0? 141: beq readdir / yes - go look at next 142: rts pc / return with r0 = &dp->d_ino 143: err: 144: clr r0 / return with 145: rts pc / dp = NULL 146: 147: loadfile: 148: clr bno / start at block 0 of inode in 'inod' 149: / read file into core until 150: / a mapping error, (no disk address) 151: clr r1 152: 1: 153: jsr pc,rmblk 154: br 1f 155: mov $buf,r2 156: 2: 157: mov (r2)+,(r1)+ 158: cmp r2,$buf+BSIZE 159: blo 2b 160: br 1b 161: / relocate core around 162: / assembler header 163: 1: 164: clr r0 165: cmp (r0),$407 166: bne 2f 167: 1: 168: mov 20(r0),(r0)+ 169: cmp r0,sp 170: blo 1b 171: / enter program and 172: / restart if return 173: 2: 174: mov ENDCORE-BOOTOPTS, r4 175: movb unit+1,r3 176: ash $3,r3 / unit # in bits 3-5, partition # is 0 177: bis $MAJOR\<8.,r3 178: mov ENDCORE-CHECKWORD, r2 179: mov csr,r1 180: jsr pc,*$0 181: jmp restart 182: 183: / read a mapped block 184: / offset in file is in bno. 185: / skip if success, no skip if fail 186: / the algorithm only handles a single 187: / indirect block. that means that 188: / files longer than NDIRIN+256 blocks (260kb) cannot 189: / be loaded. 190: rmblk: 191: add $2,(sp) 192: mov bno,r0 193: cmp r0,$NDIRIN 194: blt 1f 195: mov $NDIRIN,r0 196: 1: 197: ash $2,r0 198: mov addr+2(r0),dno 199: mov addr(r0),r0 200: bne 1f 201: tst dno 202: beq 2f 203: 1: 204: jsr pc,rblk 205: mov bno,r0 206: inc bno 207: sub $NDIRIN,r0 208: blt 1f 209: ash $2,r0 210: mov buf+2(r0),dno 211: mov buf(r0),r0 212: bne rblk 213: tst dno 214: bne rblk 215: 2: 216: sub $2,(sp) 217: 1: 218: rts pc 219: 220: read = 4 221: go = 1 222: 223: brds = -4 224: brer = -2 225: brcs = 0 / offset from base csr passed by ROMs 226: brwc = 2 227: brba = 4 228: brca = 6 229: brda = 10 230: brae = 12 231: / br disk driver. 232: / low order address in dno, 233: / high order in r0. 234: rblk: 235: mov r1,-(sp) 236: mov dno,r1 237: .if CLSIZE-1 238: ashc $CLSHFT,r0 / multiply by CLSIZE 239: .endif 240: div seccyl,r0 241: mov csr,r3 242: mov r0,brca(r3) 243: clr r0 244: div sectors,r0 245: swab r0 246: bis r1,r0 247: mov r0,brda(r3) 248: mov $buf,brba(r3) 249: mov $WC,brwc(r3) 250: mov unit,r0 251: bis $read+go,r0 252: mov r0,(r3) / brcs 253: 1: 254: tstb (r3) / brcs 255: bge 1b 256: mov (sp)+,r1 257: rts pc 258: 259: bootnm: <boot\0\0> 260: bootlen = 4 / strlen(bootnm) 261: unit: 0 262: csr: 0 263: seccyl: 0 264: sectors: 0 265: end: 266: 267: inod = ..-512.-BSIZE / room for inod, buf, stack 268: addr = inod+ADDROFF / first address in inod 269: buf = inod+INOSIZ 270: bno = buf+BSIZE 271: dno = bno+2
Defined functions
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Last modified: 1995-06-01
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