CAC 2021-12-05

DN355

The GICB is transferred to the DN355, and stars executing. It computes a ckecksum and compares it to the expected checksum; this passes; the gicb
has successfully been transferred.

It then compares the mailbox address set by the 355 configuration switches with the value that Multics expects them to see set at, and this faults; Multics is
expecting the address to be zero.

load_fnp_ writes the mailbox address into the gicb image:

/* fill in boot_comm_area */

          call phcs_$fnp_info (fnpno, mbx_absadr, term_cell, emerg_cell, code);
                                                            /* get info about this FNP */
          if code ^= 0
          then do;
               call sys_log_$error_log (1, code, me, "Getting FNP info for FNP ^a.", get_fnp_name_ (fnpno));
               go to exit;
          end;

          boot_comm_area.mbx_addr = mbx_absadr;             /* base of DIA mailbox */
          boot_comm_area.term_cell = bit (fixed (term_cell, 3), 3);
          boot_comm_area.emergency_cell = bit (fixed (emerg_cell, 3), 3);

          boot_comm_area.load_limits.low = prog_limits.low;
          boot_comm_area.load_limits.high = prog_limits.high;

boot_comm_area in gicb:

       00736  0 00000               463 .rtrn. ind     **              spring loaded vector for
       00737  4 71 777      736     464        tra     -1,*            extraneous interrupts

                                    627        ttls    bootload communication block
                                    628
                   01174            629 tbtcom even
                  001234            630 end    equ     *+32            last location to be included in checksum
                                    631                                of bootload program
                   00740            632        loc     480
                                    633
                                    634                mcs/fnp list icw control block
                                    635
       00740  1 00742               636 iclist dcw     icdcw1,**       list icw
       00741  000000
       00742  000000                637 icdcw1 vfd     18/,18/diactf   dcw number one
       00743  000076
       00744  101000                638        vfd     3/w.2,15/.mcs.  load 0 - 8k
       00745  000000                639        vfd     6/0,12/0
       00746  000000                640 icdcw2 vfd     18/,18/diactf   dcw number two
       00747  000076
       00750  121000                641        vfd     3/w.2,15/.mcs.+8192 load 8 - 16k
       00751  000000                642        vfd     6/0,12/0
       00752  000000                643 icdcw3 vfd     18/,18/diactf   dcw number three
       00753  000076
       00754  141000                644        vfd     3/w.2,15/.mcs.+16384 load 16 - 24k
       00755  000000                645        vfd     6/0,12/0
       00756  000000                646 icdcw4 vfd     18/,18/diactf   dcw number four
       00757  000076
       00760  161000                647        vfd     3/w.2,15/.mcs.+24576 load 24 - 32k
       00761  000000                648        vfd     6/0,12/0
       00762  000000                649 icdcw5 vfd     18/,18/diadis   dcw number five - disconnect
       00763  000070
       00764  000000                650        vfd     18/0,18/0
       00765  000000
       00766  000000                651 dimbx  dec     0               cs mailbox address
       00767  000000                652 icintn dec     0               cs interrupt cells
       00770  000000                653        dec     0,0             unused
       00771  000000
       00772  000000                654 iclmts dec     0,0             mcs load limits
       00773  000000
  end of binary card gicb0015
       00774  000000                655 icksma dec     0,0             mcs checksum

The values of the boot comm area has sent by load_fnp_

01174:100742    iclist
01175:000010
01176:010600   icdcw1
01177:000076
01200:101000
01201:040000
01202:020600   icdcw2
01203:000076
01204:121000
01205:020000
01206:030600   icdcw3
01207:060076
01210:141000
01211:007204
01212:000000   icdcw4
01213:060070
01214:100000
01215:020000
01216:000000   icdcw5
01217:000070
01220:000000
01221:000000
01222:003400  dimbx
01223:000037
01224:000000
01225:000000
01226:000000
01227:056410
01230:330707
01231:261613
01232:723652
01233:611260

Wierd. That's correct.

Ahh. I misread gicb; the problem is the mbx address reported by the dn355 is zero.