;
-; Ullrich von Bassewitz, 2003-03-07
-; Stefan Haubenthal, 2011-01-28
+; 2003-03-07, Ullrich von Bassewitz
+; 2011-01-28, Stefan Haubenthal
+; 2014-09-10, Greg King
;
-; Setup arguments for main
+; Set up arguments for main
;
- .constructor initmainargs, 24
- .import __argc, __argv
- .macpack generic
+ .constructor initmainargs, 24
+ .import __argc, __argv
-MAXARGS = 10 ; Maximum number of arguments allowed
-REM = $9d ; BASIC token-code
-NAME_LEN = 16 ; maximum length of command-name
-BASIC_BUF = $35
-FNAM = $293
+ .include "atmos.inc"
+ .macpack generic
+
+MAXARGS = 10 ; Maximum number of arguments allowed
+REM = $9D ; BASIC token-code
;---------------------------------------------------------------------------
-; Get possible command-line arguments. Goes into the special INIT segment,
-; which may be reused after the startup code is run
+; Get possible command-line arguments. Goes into the special ONCE segment,
+; which will be reused after the startup code is run.
-.segment "INIT"
+.segment "ONCE"
-.proc initmainargs
+.proc initmainargs
; Assume that the program was loaded, a moment ago, by the traditional LOAD
; statement. Save the "most-recent filename" as argument #0.
-; Because the buffer, that we're copying into, was zeroed out,
-; we don't need to add a NUL character.
-;
- ldy #NAME_LEN - 1 ; limit the length
-L0: lda FNAM,y
- sta name,y
- dey
- bpl L0
- inc __argc ; argc always is equal to, at least, 1
+
+ ldy #FNAME_LEN ; Limit the length
+ lda #0 ; The terminating NUL character
+ beq L1 ; Branch always
+L0: lda CFOUND_NAME,y
+L1: sta name,y
+ dey
+ bpl L0
+ inc __argc ; argc always is equal to, at least, 1
; Find the "rem" token.
-;
- ldx #0
-L2: lda BASIC_BUF,x
- beq done ; no "rem," no args.
- inx
- cmp #REM
- bne L2
- ldy #1 * 2
+
+ ldx #0
+L2: lda BASIC_BUF,x
+ beq done ; No "rem", no args.
+ inx
+ cmp #REM
+ bne L2
+
+; The arguments must be copied to a safe place because BASIC's input buffer
+; might be re-used by the stdin console.
+
+ ldy #(SCREEN_XSIZE * 2 - 1) - 1
+L3: lda BASIC_BUF,y
+ sta args,y
+ dey
+ bpl L3
+
+ ldy #1 * 2 ; Point to second argv slot
; Find the next argument
-next: lda BASIC_BUF,x
- beq done ; End of line reached
- inx
- cmp #' ' ; Skip leading spaces
- beq next ;
+next: lda BASIC_BUF,x
+ beq done ; End of line reached
+ inx
+ cmp #' ' ; Skip leading spaces
+ beq next
; Found start of next argument. We've incremented the pointer in X already, so
; it points to the second character of the argument. This is useful since we
; will check now for a quoted argument, in which case we will have to skip this
; first character.
-found: cmp #'"' ; Is the argument quoted?
- beq setterm ; Jump if so
- dex ; Reset pointer to first argument character
- lda #' ' ; A space ends the argument
-setterm:sta term ; Set end of argument marker
+found: cmp #'"' ; Is the argument quoted?
+ beq setterm ; Jump if so
+ dex ; Reset pointer to first argument character
+ lda #' ' ; A space ends the argument
+setterm:sta term ; Set end of argument marker
-; Now store a pointer to the argument into the next slot. Since the BASIC
-; input buffer is located at the zero page, no calculations are necessary.
+; Now, store a pointer, to the argument, into the next slot.
- txa ; Get low byte
- add #<BASIC_BUF ; Not at page boundary
- sta argv,y ; argv[y]= &arg
- iny
- iny
- inc __argc ; Found another arg
+ txa ; Get low byte
+ add #<args
+ sta argv,y ; argv[y]=&arg
+ lda #>$0000
+ adc #>args
+ sta argv+1,y
+ iny
+ iny
+ inc __argc ; Found another arg
; Search for the end of the argument
-argloop:lda BASIC_BUF,x
- beq done
- inx
- cmp term
- bne argloop
+argloop:lda BASIC_BUF,x
+ beq done
+ inx
+ cmp term
+ bne argloop
; We've found the end of the argument. X points one character behind it, and
; A contains the terminating character. To make the argument a valid C string,
; replace the terminating character by a zero.
- lda #0
- sta BASIC_BUF-1,x
+ lda #0
+ sta args-1,x
; Check if the maximum number of command line arguments is reached. If not,
; parse the next one.
- lda __argc ; Get low byte of argument count
- cmp #MAXARGS ; Maximum number of arguments reached?
- bcc next ; Parse next one if not
+ lda __argc ; Get low byte of argument count
+ cmp #MAXARGS ; Maximum number of arguments reached?
+ bcc next ; Parse next one if not
; (The last vector in argv[] already is NULL.)
-done: lda #<argv
- ldx #>argv
- sta __argv
- stx __argv + 1
-
- rts
+done: lda #<argv
+ ldx #>argv
+ sta __argv
+ stx __argv + 1
+ rts
.endproc
-; These arrays are zeroed before initmainargs is called.
-; char name[16+1];
-; char* argv[MAXARGS+1]={name};
-;
-.bss
-term: .res 1
-name: .res NAME_LEN + 1
+.segment "INIT"
+
+term: .res 1
+name: .res FNAME_LEN + 1
+args: .res SCREEN_XSIZE * 2 - 1
.data
-argv: .addr name
- .res MAXARGS * 2
+
+; This array has zeroes when initmainargs starts.
+; char* argv[MAXARGS+1]={name};
+
+argv: .addr name
+ .res MAXARGS * 2
projects / cc65 / blobdiff