[Coco] How to use the syscall for mdir.

[Greg]

On 4/28/2021 10:01:07 AM, coco at jechar.ca wrote:

>I am trying to understand how the F$GModDr is used it seems to require
>three parameters regs.x regs.y and regs.u I think I understand what is
>required for regs.x but have no clue what to provide for regs.y and regs.u
>
>I have included enough proposed code (below) to give a clear idea of what I
>am trying to accomplish.
>
>I have no clue where to go from here, can anyone help ?
>
>  PROCEDURE pmdir
>
>(* Demo reimplementation of mdir to ilistrate syscall use.               *)
>(* In this reimplementation 15 , 32 character lines are shown at a time. *)
>
>(* F$GModDr 103F 1A
>(*   ENTRY
>(*          X = Pointer to 2K buffer
>(*          y = End of copied module directory
>(*          u = start address of system module directory.
>(*
>
I think Y and U are exit conditions instead of entry conditions so the 
documentation should be more like this:

Entry Conditions:
X = pointer to a 2048-byte buffer

Exit Conditions:
Y = end of copied module directory
U = start address of the system module directory

Y points to the last byte of the module directory in your buffer, 
although I don't remember what the address in U can be used for.