1: MAJOR = 6 / major # from bdevsw[] 2: 3: / RK05 bootstrap. 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: clr r0 64: / clear core to make things clean 65: 2: 66: clr (r0)+ 67: cmp r0,sp 68: blo 2b 69: 70: / initialize rk 71: mov csr,r1 72: mov $reset+go,rkcs(r1) / reset controller 73: 74: mov $bootnm, r1 75: mov $2,r0 / ROOTINO 76: jsr pc,iget 77: clr r2 / offset 78: again: 79: jsr pc,readdir 80: beq restart / error - restart 81: mov 4(r0),r4 / dp->d_namlen 82: cmp r4,$bootlen / if (bootlen == dp->d_namlen) 83: bne again / nope, go try next entry 84: mov r0,r3 85: add $6,r3 / r3 = dp->d_name 86: mov r1,r5 / r5 = filename 87: 9: 88: cmpb (r3)+,(r5)+ 89: bne again / no match - go read next entry 90: sob r4,9b 91: mov (r0),r0 / r0 = dp->d_ino 92: jsr pc,iget / fetch boot's inode 93: br loadfile / 'boot'- go read it 94: 95: / get the inode specified in r0 96: iget: 97: add $INOFF,r0 98: mov r0,r5 99: ash $PBSHFT,r0 100: bic $!7777,r0 101: mov r0,dno 102: clr r0 103: jsr pc,rblk 104: bic $!17,r5 105: mov $INOSIZ,r0 106: mul r0,r5 107: add $buf,r5 108: mov $inod,r4 109: 1: 110: movb (r5)+,(r4)+ 111: sob r0,1b 112: rts pc 113: 114: readdir: 115: bit $BSIZE-1,r2 116: bne 1f 117: jsr pc,rmblk / read mapped block (bno) 118: br err / end of file branch 119: clr r2 / start at beginning of buf 120: 1: 121: mov $buf,r0 122: add r2,r0 / dp = buf+offset 123: add buf+2(r2),r2 / dp += dp->d_reclen 124: tst (r0) / dp->d_ino == 0? 125: beq readdir / yes - go look at next 126: rts pc / return with r0 = &dp->d_ino 127: err: 128: clr r0 / return with 129: rts pc / dp = NULL 130: 131: loadfile: 132: clr bno / start at block 0 of inode in 'inod' 133: / read file into core until 134: / a mapping error, (no disk address) 135: clr r1 136: 1: 137: jsr pc,rmblk 138: br 1f 139: mov $buf,r2 140: 2: 141: mov (r2)+,(r1)+ 142: cmp r2,$buf+BSIZE 143: blo 2b 144: br 1b 145: / relocate core around 146: / assembler header 147: 1: 148: clr r0 149: cmp (r0),$407 150: bne 2f 151: 1: 152: mov 20(r0),(r0)+ 153: cmp r0,sp 154: blo 1b 155: / enter program and 156: / restart if return 157: 2: 158: mov ENDCORE-BOOTOPTS, r4 159: mov unit,r3 160: ash $3,r3 / unit # in bits 3-5, partition # is 0 161: bis $MAJOR\<8.,r3 162: mov ENDCORE-CHECKWORD, r2 163: mov csr,r1 164: jsr pc,*$0 165: br restart 166: 167: / read a mapped block 168: / offset in file is in bno. 169: / skip if success, no skip if fail 170: / the algorithm only handles a single 171: / indirect block. that means that 172: / files longer than NDIRIN+256 blocks (260kb) cannot 173: / be loaded. 174: rmblk: 175: add $2,(sp) 176: mov bno,r0 177: cmp r0,$NDIRIN 178: blt 1f 179: mov $NDIRIN,r0 180: 1: 181: ash $2,r0 182: mov addr+2(r0),dno 183: mov addr(r0),r0 184: bne 1f 185: tst dno 186: beq 2f 187: 1: 188: jsr pc,rblk 189: mov bno,r0 190: inc bno 191: sub $NDIRIN,r0 192: blt 1f 193: ash $2,r0 194: mov buf+2(r0),dno 195: mov buf(r0),r0 196: bne rblk 197: tst dno 198: bne rblk 199: 2: 200: sub $2,(sp) 201: 1: 202: rts pc 203: 204: read = 4 205: reset = 0 206: go = 1 207: 208: rkcs = 0 / offset from base csr 209: rkwc = 2 210: rkba = 4 211: rkda = 6 212: / rk05 disk driver. 213: / low order address in dno, 214: / high order in r0. 215: rblk: 216: mov r1,-(sp) 217: mov dno,r1 218: .if CLSIZE-1 219: ashc $CLSHFT,r0 / multiply by CLSIZE 220: .endif 221: div $12.,r0 222: ash $4,r0 223: bis r1,r0 224: mov unit,r3 225: ash $13.,r3 226: bis r3,r0 227: mov csr,r3 228: mov r0,rkda(r3) / stuff disc address 229: mov $buf,rkba(r3) / where to put it. 230: mov $WC,rkwc(r3) / yes sir, yes sir, three bags full 231: mov $read+go,(r3) / rkcs - press the button 232: 1: 233: tstb (r3) / rkcs 234: bge 1b 235: mov (sp)+,r1 236: rts pc 237: 238: bootnm: <boot\0\0> 239: bootlen = 4 / strlen(bootnm) 240: unit: 0 241: csr: 0 242: end: 243: 244: inod = ..-512.-BSIZE / room for inod, buf, stack 245: addr = inod+ADDROFF / first address in inod 246: buf = inod+INOSIZ 247: bno = buf+BSIZE 248: dno = bno+2
Defined functions
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Last modified: 1995-06-01
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