Parameter

Description

Execution result (output)

0: Terminated normally

-1: Error

File number (input)

Number that is returned when a file is opened

Offset (output)

Current position of the file pointer (Number of bytes from the top of the file)

_fptell:

        MOV.L       R2,R5           ; Set the value of R2 (offset) in R5.

        MOV.L       #PARM,R2        ; Set the address of the parameter block in R2.

        MOV.B       R1,1h:5[R2]   ; Set the value of R1 (file number) in R2 + 1 bytes 

                                    ; (direction).

        MOV.L       #010D0000h,R1   ; Set the function code of FTELL in R1.

        MOV.L       #SIM_IO,R3      ; Set the address of the system call in R3.

        JSR         R3              ; System call

        NOP

        MOV.L       #PARM,R2        ; Set the address of the parameter block in R2.

        MOV.L       4h:5[R2],R1   ; Set the value of R2 + 4 bytes (new offset) in R1.

        MOV.L       R1,[R5]   ; Set the value of R1 in the location pointed to by R5 

                              ; (offset pointer).

        MOV.B       [R2],R1   ; Set the first byte of R2 (result of execution) in R1.

        RTS                   ; Return to the address where the function was called.

         .SECTION  B,DATA,ALIGN=4

PARM:       .BLKL   2               ; Parameter block area