2.11BSD#431 - /usr/src/sys/mdec/boilerplate

   1:         mov     $bootnm, r1
   2:         mov     $2,r0                   / ROOTINO
   3:         jsr     pc,iget
   4:         clr     r2                      / offset
   5: again:
   6:         jsr     pc,readdir
   7:         beq     restart                 / error - restart
   8:         mov     4(r0),r4                / dp->d_namlen
   9:         cmp     r4,$bootlen             / if (len == dp->d_namlen)
  10:         bne     again                   /    nope, go try next entry
  11:         mov     r0,r3
  12:         add     $6,r3                   / r3 = dp->d_name
  13:         mov     r1,r5                   / r5 = filename
  14: 9:
  15:         cmpb    (r3)+,(r5)+
  16:         bne     again                   / no match - go read next entry
  17:         sob     r4,9b
  18:         mov     (r0),r0                 / r0 = dp->d_ino
  19:         jsr     pc,iget                 / fetch boot's inode
  20:         br      loadfile                / 'boot'- go read it
  21: 
  22: / get the inode specified in r0
  23: iget:
  24:         add     $INOFF,r0
  25:         mov     r0,r5
  26:         ash     $PBSHFT,r0
  27:         bic     $!7777,r0
  28:         mov     r0,dno
  29:         clr     r0
  30:         jsr     pc,rblk
  31:         bic     $!17,r5
  32:         mov     $INOSIZ,r0
  33:         mul     r0,r5
  34:         add     $buf,r5
  35:         mov     $inod,r4
  36: 1:
  37:         movb    (r5)+,(r4)+
  38:         sob     r0,1b
  39:         rts     pc
  40: 
  41: readdir:
  42:         bit     $BSIZE-1,r2
  43:         bne     1f
  44:         jsr     pc,rmblk                / read mapped block (bno)
  45:                 br err                  / end of file branch
  46:         clr     r2                      / start at beginning of buf
  47: 1:
  48:         mov     $buf,r0
  49:         add     r2,r0                   / dp = buf+offset
  50:         add     buf+2(r2),r2            / dp += dp->d_reclen
  51:         tst     (r0)                    / dp->d_ino == 0?
  52:         beq     readdir                 / yes - go look at next
  53:         rts     pc                      / return with r0 = &dp->d_ino
  54: err:
  55:         clr     r0                      / return with
  56:         rts     pc                      / dp = NULL
  57: 
  58: loadfile:
  59:         clr     bno                     / start at block 0 of inode in 'inod'

Defined functions