diff --git a/libsrc/pet/crt0.s b/libsrc/pet/crt0.s index 89582885e..1d5641a7c 100644 --- a/libsrc/pet/crt0.s +++ b/libsrc/pet/crt0.s @@ -42,11 +42,19 @@ L1: lda sp,x jsr CLRCH -; Switch to second charset +; Switch to second charset. The routine that is called by BSOUT to switch the +; character set will use FNLEN as temporary storage - YUCK! Since the +; initmainargs routine, which parses the command line for arguments needs this +; information, we need to save and restore it here. +; Thanks to Stefan Haubenthal for this information! + lda FNLEN + pha ; Save FNLEN lda #14 ; sta $E84C ; See PET FAQ jsr BSOUT + pla + sta FNLEN ; Restore FNLEN ; Clear the BSS data diff --git a/libsrc/pet/mainargs.s b/libsrc/pet/mainargs.s index a9233382f..a5892a49c 100644 --- a/libsrc/pet/mainargs.s +++ b/libsrc/pet/mainargs.s @@ -1,24 +1,125 @@ ; ; Ullrich von Bassewitz, 2003-03-07 +; Stefan Haubenthal, 2008-08-11 ; ; Setup arguments for main ; + .constructor initmainargs, 24 + .import __argc, __argv - .constructor initmainargs, 24 - .import __argc, __argv + .include "pet.inc" + +MAXARGS = 10 ; Maximum number of arguments allowed +REM = $8f ; BASIC token-code +NAME_LEN = 16 ; maximum length of command-name +BASIC_BUF= $200 ;--------------------------------------------------------------------------- ; Get possible command-line arguments. Goes into the special INIT segment, ; which may be reused after the startup code is run -.segment "INIT" +.segment "INIT" -.proc initmainargs +.proc initmainargs - rts +; 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 FNLEN + cpy #NAME_LEN + 1 + bcc L1 + ldy #NAME_LEN - 1 ; limit the length +L0: lda (FNADR),y + sta name,y +L1: 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 + +; Find the next argument + +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 + +; 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. + + txa ; Get low byte + sta argv,y ; argv[y]= &arg + iny + lda #>BASIC_BUF + sta argv,y + 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 + +; 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 + +; 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 + +; (The last vector in argv[] already is NULL.) + +done: lda #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 +.data +argv: .addr name + .res MAXARGS * 2