New version from Oliver Schmidt

git-svn-id: svn://svn.cc65.org/cc65/trunk@3736 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/apple2/mainargs.s b/libsrc/apple2/mainargs.s
index aa0ad5d3289d12fb5387ff4cca09de94e9f71697..a6a2e372fbcfda200a8a591ae8a3658b6821ca29 100644 (file)
--- a/libsrc/apple2/mainargs.s
+++ b/libsrc/apple2/mainargs.s
@@ -33,20 +33,28 @@
 
 MAXARGS = 10
 
+; ProDOS stores the filename in the second half of BASIC's input buffer, so
+; there are 128 characters left. At least 7 characters are necessary for the
+; CALLxxxx:REM so 121 characters may be used before overwriting the ProDOS
+; filename. As we don't want to put further restrictions on the command-line
+; length we reserve those 121 characters terminated by a zero.
+
+BUF_LEN = 122
+
 BASIC_BUF = $200
 FNAM_LEN  = $280
 FNAM      = $281
 REM       = $B2                        ; BASIC token-code
 
 ; Get possible command-line arguments. Goes into the special INIT segment,
-; which may be reused after the startup code is run
+; which may be reused after the startup code is run.
 
         .segment        "INIT"
 
 initmainargs:
 
 ; Assume that the program was loaded, a moment ago, by the traditional BLOAD
-; statement of BASIC.SYSTEM. Save the "most-recent filename" as argument #0.
+; statement of BASIC.SYSTEM. Save the filename as argument #0 if available.
 
         ldx    __dos_type      ; No ProDOS -> argv[0] = ""
         beq    :+
@@ -67,7 +75,25 @@ initmainargs:
         inx
         cmp    #REM
         bne    :-
-        ldy    #$01 * 2        ; Start with argv[1]
+
+; If a clock is present it is called by ProDOS on file operations. On machines
+; with a slot-based clock (like the Thunder Clock) the clock firmware places
+; the current date in BASIC's input buffer. Therefore we have to create a copy
+; of the command-line in a different buffer before the original is potentially
+; destroyed.
+
+       ldy     #$00
+:      lda     BASIC_BUF,x
+       sta     buffer,y
+       inx
+       iny
+       cpy     #BUF_LEN - 1    ; Keep the terminating zero intact
+       bcc     :-
+
+; Start processing the arguments.
+
+       ldx     #$00
+       ldy     #$01 * 2        ; Start with argv[1]
 
 ; Find the next argument. Stop if the end of the string or a character with the
 ; hibit set is reached. The later is true if the string isn't already parsed by
@@ -79,7 +105,7 @@ initmainargs:
 ; for the REM token we stumbled across the first '2' character ($32+$80 = $B2)
 ; and interpreted the rest of the date as a spurious command-line parameter.
 
-next:   lda    BASIC_BUF,x
+next:   lda    buffer,x
         beq    done
         bmi    done
         inx
@@ -92,39 +118,40 @@ next:   lda        BASIC_BUF,x
 ; first character.
 
         cmp    #'"'            ; Is the argument quoted?
-        beq    setterm         ; Jump if so
+        beq    :+              ; Jump if so
         dex                    ; Reset pointer to first argument character
         lda    #' '            ; A space ends the argument
-setterm:sta     tmp1           ; Set end of argument marker
+:       sta     tmp1           ; 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 start of a RAM page, no calculations are
-; necessary.
+; Now store a pointer to the argument into the next slot.
 
         txa                    ; Get low byte
+        clc
+        adc    #<buffer
         sta    argv,y          ; argv[y] = &arg
         iny
-        lda    #>BASIC_BUF
+        lda    #$00
+        adc    #>buffer
         sta    argv,y
         iny
         inc    __argc          ; Found another arg
 
-; Search for the end of the argument
+; Search for the end of the argument.
 
-argloop:lda     BASIC_BUF,x
+:       lda     buffer,x
         beq    done
         inx
         cmp    tmp1
-        bne    argloop
+        bne    :-
 
 ; 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    #$00
-        sta    BASIC_BUF-1,x
+        sta    buffer-1,x
 
-; Check if the maximum number of command line arguments is reached. If not,
+; 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
@@ -146,3 +173,7 @@ done:   lda #<argv
 
 argv:   .addr  FNAM
         .res   MAXARGS * 2
+
+       .bss
+
+buffer:        .res    BUF_LEN
\ No newline at end of file