1: MAJOR = 10. / major # from bdevsw[] 2: 3: / Bootstrap for Diva Comp. IV controller (33 sectors) 4: / 5: / 1995/05/31 - The unit number needs to go in bits 3-5 of bootdev 6: / because the partition number now goes into bits 0-2. 7: / 8: / disk boot program to load and transfer 9: / to a unix entry. 10: / for use with 1 KB byte blocks, CLSIZE is 2. 11: / NDIRIN is the number of direct inode addresses (currently 4) 12: / assembled size must be <= 512; if > 494, the 16-byte a.out header 13: / must be removed 14: 15: / options: none. all options of reading an alternate name or echoing to 16: / the keyboard had to be removed to make room for the 17: / code which understands the new directory structure on disc 18: 19: / constants: 20: CLSIZE = 2. / physical disk blocks per logical block 21: CLSHFT = 1. / shift to multiply by CLSIZE 22: BSIZE = 512.*CLSIZE / logical block size 23: INOSIZ = 64. / size of inode in bytes 24: NDIRIN = 4. / number of direct inode addresses 25: ADDROFF = 12. / offset of first address in inode 26: INOPB = BSIZE\/INOSIZ / inodes per logical block 27: INOFF = 31. / inode offset = (INOPB * (SUPERB+1)) - 1 28: PBSHFT = -4 / shift to divide by inodes per block 29: WC = -256.*CLSIZE / word count 30: 31: / The boot options and device are placed in the last SZFLAGS bytes 32: / at the end of core by the kernel for autobooting. 33: ENDCORE= 160000 / end of core, mem. management off 34: SZFLAGS= 6 / size of boot flags 35: BOOTOPTS= 2 / location of options, bytes below ENDCORE 36: BOOTDEV= 4 37: CHECKWORD= 6 38: 39: .. = ENDCORE-512.-SZFLAGS / save room for boot flags 40: 41: / entry is made by jsr pc,*$0 42: / so return can be rts pc 43: 44: / establish sp, copy 45: / program up to end of core. 46: 47: nop / These two lines must be present or DEC 48: br start / boot ROMs will refuse to run boot block! 49: start: 50: mov r0,unit 51: mov r1,csr 52: mov $..,sp 53: mov sp,r1 54: clr r0 55: 1: 56: mov (r0)+,(r1)+ 57: cmp r1,$end 58: blo 1b 59: jmp *$2f 60: 61: / On error, restart from here. 62: restart: 63: 64: / clear core to make things clean 65: clr r0 66: 2: 67: clr (r0)+ 68: cmp r0,sp 69: blo 2b 70: 71: / initialize disk 72: mov csr,r1 73: mov unit,hpcs2(r1) 74: mov $preset+go,hpcs1(r1) 75: mov $fmt22,hpof(r1) 76: 77: mov $bootnm, r1 78: mov $2,r0 / ROOTINO 79: jsr pc,iget 80: clr r2 / offset 81: again: 82: jsr pc,readdir 83: beq restart / error - restart 84: mov 4(r0),r4 / dp->d_namlen 85: cmp r4,$bootlen / if (bootlen == dp->d_namlen) 86: bne again / nope, go try next entry 87: mov r0,r3 88: add $6,r3 / r3 = dp->d_name 89: mov r1,r5 / r5 = filename 90: 9: 91: cmpb (r3)+,(r5)+ 92: bne again / no match - go read next entry 93: sob r4,9b 94: mov (r0),r0 / r0 = dp->d_ino 95: jsr pc,iget / fetch boot's inode 96: br loadfile / 'boot'- go read it 97: 98: / get the inode specified in r0 99: iget: 100: add $INOFF,r0 101: mov r0,r5 102: ash $PBSHFT,r0 103: bic $!7777,r0 104: mov r0,dno 105: clr r0 106: jsr pc,rblk 107: bic $!17,r5 108: mov $INOSIZ,r0 109: mul r0,r5 110: add $buf,r5 111: mov $inod,r4 112: 1: 113: movb (r5)+,(r4)+ 114: sob r0,1b 115: rts pc 116: 117: readdir: 118: bit $BSIZE-1,r2 119: bne 1f 120: jsr pc,rmblk / read mapped block (bno) 121: br err / end of file branch 122: clr r2 / start at beginning of buf 123: 1: 124: mov $buf,r0 125: add r2,r0 / dp = buf+offset 126: add buf+2(r2),r2 / dp += dp->d_reclen 127: tst (r0) / dp->d_ino == 0? 128: beq readdir / yes - go look at next 129: rts pc / return with r0 = &dp->d_ino 130: err: 131: clr r0 / return with 132: rts pc / dp = NULL 133: 134: loadfile: 135: clr bno / start at block 0 of inode in 'inod' 136: / read file into core until 137: / a mapping error, (no disk address) 138: clr r1 139: 1: 140: jsr pc,rmblk 141: br 1f 142: mov $buf,r2 143: 2: 144: mov (r2)+,(r1)+ 145: cmp r2,$buf+BSIZE 146: blo 2b 147: br 1b 148: / relocate core around 149: / assembler header 150: 1: 151: clr r0 152: cmp (r0),$407 153: bne 2f 154: 1: 155: mov 20(r0),(r0)+ 156: cmp r0,sp 157: blo 1b 158: / enter program and 159: / restart if return 160: 2: 161: mov ENDCORE-BOOTOPTS, r4 162: mov unit,r3 163: ash $3,r3 / unit # in bits 3-5, partition # is 0 164: bis $MAJOR\<8.,r3 165: mov ENDCORE-CHECKWORD, r2 166: mov csr,r1 167: jsr pc,*$0 168: br restart 169: 170: / read a mapped block 171: / offset in file is in bno. 172: / skip if success, no skip if fail 173: / the algorithm only handles a single 174: / indirect block. that means that 175: / files longer than NDIRIN+256 blocks (260kb) cannot 176: / be loaded. 177: rmblk: 178: add $2,(sp) 179: mov bno,r0 180: cmp r0,$NDIRIN 181: blt 1f 182: mov $NDIRIN,r0 183: 1: 184: ash $2,r0 185: mov addr+2(r0),dno 186: mov addr(r0),r0 187: bne 1f 188: tst dno 189: beq 2f 190: 1: 191: jsr pc,rblk 192: mov bno,r0 193: inc bno 194: sub $NDIRIN,r0 195: blt 1f 196: ash $2,r0 197: mov buf+2(r0),dno 198: mov buf(r0),r0 199: bne rblk 200: tst dno 201: bne rblk 202: 2: 203: sub $2,(sp) 204: 1: 205: rts pc 206: 207: read = 70 208: preset = 20 209: go = 1 210: fmt22 = 10000 211: 212: hpcs1 = 0 / offset from base csr 213: hpda = hpcs1+6 214: hpcs2 = hpcs1+10 215: hpds = hpcs1+12 216: hpof = hpcs1+32 217: hpca = hpcs1+34 218: 219: / rp0456 disk driver. 220: / low order address in dno, 221: / high order in r0. 222: rblk: 223: mov r1,-(sp) 224: mov dno,r1 225: .if CLSIZE-1 226: ashc $CLSHFT,r0 / multiply by CLSIZE 227: .endif 228: div $33.*19.,r0 229: mov csr,r3 230: mov r0,hpca(r3) 231: clr r0 232: div $33.,r0 233: swab r0 234: bis r1,r0 235: add $hpcs2,r3 236: mov unit,(r3) 237: mov r0,-(r3) 238: mov $buf,-(r3) 239: mov $WC,-(r3) 240: mov $read+go,-(r3) 241: 1: 242: tstb (r3) 243: bge 1b 244: mov (sp)+,r1 245: rts pc 246: 247: bootnm: <boot\0\0> 248: bootlen = 4 / strlen(bootnm) 249: unit: 0 250: csr: 0 251: end: 252: 253: inod = ..-512.-BSIZE / room for inod, buf, stack 254: addr = inod+ADDROFF / first address in inod 255: buf = inod+INOSIZ 256: bno = buf+BSIZE 257: dno = bno+2
Defined functions
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Last modified: 1995-06-01
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