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cc65/libsrc/apple2/exec.s
Oliver Schmidt 3c1cd0d867 Added cmdline support to exec().
The starting point is the CALL2051:REM <cmdline> approach. It uses the BASIC input buffer at $200. ProDOS stores the name of the loaded program at $280 (which we want for argv[0]) leaving us with 128 char buffer. If we run the program via exec() we don't need the CALL2051 but only the REM token (which is just one char). So have a maximum cmdline length of 126 (plus a terminating zero).

There's no specification for ProDOS BIN file cmdline parameters so exec() just supports the CALL2051:REM <cmdline> approach. In contrast ProDOS SYS files allow for a 'startup filename'. A ProDOS filename is short than 126 chars so having exec() general cut the cmdline after 126 chars seems reasonable. If the SYS file we exec() allows for less we cut the cmdline further.

Our 'loader.system' SYS file however allows for an unusually 126 char long "startup filename" as it is targeted towards cc65 BIN porgrams with their 126 cmdline length.
2015-04-26 14:09:20 +02:00

292 lines
8.4 KiB
ArmAsm

;
; Oliver Schmidt, 2011-01-26
;
; int __fastcall__ exec (const char* progname, const char* cmdline);
;
.export _exec
.import pushname, popname
.import popax, done, _exit
.include "zeropage.inc"
.include "errno.inc"
.include "apple2.inc"
.include "mli.inc"
; Wrong file type
typerr: lda #$4A ; "Incompatible file format"
; Cleanup name
oserr: jsr popname ; Preserves A
; Set __oserror
jmp __mappederrno
_exec:
; Save cmdline
sta ptr4
stx ptr4+1
; Get and push name
jsr popax
jsr pushname
bne oserr
; ProDOS TechRefMan, chapter 5.1.5.1:
; "The complete or partial pathname of the system program
; is stored at $280, starting with a length byte."
; In fact BASIC.SYSTEM does the same for BLOAD and BRUN of
; binary programs so we should do the same too in any case
; especially as _we_ rely on it in mainargs.s for argv[0]
ldy #$00
lda (sp),y
tay
: lda (sp),y
sta $0280,y
dey
bpl :-
; Set pushed name
lda sp
ldx sp+1
sta mliparam + MLI::INFO::PATHNAME
stx mliparam + MLI::INFO::PATHNAME+1
; Get file_type and aux_type
lda #GET_INFO_CALL
ldx #GET_INFO_COUNT
jsr callmli
bcs oserr
; If we get here the program file at least exists so we copy
; the loader stub right now and patch it later to set params
ldx #size - 1
: lda source,x
sta target,x
dex
bpl :-
; Check program file type
lda mliparam + MLI::INFO::FILE_TYPE
cmp #$FF ; SYS file?
bne binary ; No, check for BIN file
sta file_type ; Save file type for cmdline handling
; SYS programs replace BASIC.SYSTEM so set in the ProDOS system bit map
; protection for pages $80 - $BF just in case BASIC.SYSTEM is there now
ldx #$0F ; Start with protection for pages $B8 - $BF
lda #%00000001 ; Protect only system global page
: sta $BF60,x ; Set protection for 8 pages
lda #%00000000 ; Protect no page
dex
bpl :-
bmi prodos ; Branch always
binary: cmp #$06 ; BIN file?
bne typerr ; No, wrong file type
; Set BIN program load addr
lda mliparam + MLI::INFO::AUX_TYPE
ldx mliparam + MLI::INFO::AUX_TYPE+1
sta data_buffer
stx data_buffer+1
; Check ProDOS system bit map for presence of BASIC.SYSTEM
lda $BF6F ; Protection for pages $B8 - $BF
cmp #%00000001 ; Exactly system global page is protected
beq setvec
; Get highest available mem addr from BASIC.SYSTEM
ldx HIMEM+1 ; High byte
bne setbuf ; Branch always
; BIN programs are supposed to quit through one of the two DOS
; vectors so we set up those to point to the ProDOS dispatcher
setvec: ldx #$03 - 1 ; Size of JMP opcode
: lda dosvec,x
sta DOSWARM,x ; DOS warm start
sta DOSWARM + 3,x ; DOS cold start
dex
bpl :-
; No BASIC.SYSTEM so use addr of ProDOS system global page
prodos: ldx #>$BF00 ; High byte
; The I/O buffer needs to be page aligned
setbuf: lda #$00 ; Low byte
; The I/O buffer needs four pages
dex
dex
dex
dex
; Set I/O buffer
sta mliparam + MLI::OPEN::IO_BUFFER
stx mliparam + MLI::OPEN::IO_BUFFER+1
; PATHNAME already set
.assert MLI::OPEN::PATHNAME = MLI::INFO::PATHNAME, error
; Lower file level to avoid program file
; being closed by C libary shutdown code
ldx LEVEL
stx level
beq :+
dec LEVEL
; Open file
: lda #OPEN_CALL
ldx #OPEN_COUNT
jsr callmli
; Restore file level
ldx level
stx LEVEL
bcc :+
jmp oserr
; Get and save fd
: lda mliparam + MLI::OPEN::REF_NUM
sta read_ref
sta close_ref
.ifdef __APPLE2ENH__
; Calling the 80 column firmware needs the ROM switched
; in, otherwise it copies the F8 ROM to the LC (@ $CEF4)
bit $C082
; ProDOS TechRefMan, chapter 5.3.1.3:
; "80-column text cards -- and other Apple IIe features -- can
; be turned off using the following sequence of instructions:"
lda #$15
jsr $C300
; Switch in LC bank 2 for R/O
bit $C080
.endif
; Reset stack we already passed
; the point of no return anyway
ldx #$FF
txs
; Store up to 127 chars of cmdline (if any)
; including terminating zero in stack page
ldy #$00
lda ptr4+1 ; NULL?
beq :++ ; Yes, store as '\0'
: lda (ptr4),y
: sta $0100,y
beq :+ ; '\0' stored, done
iny
cpy #$7E
bcc :--
lda #$00 ; '\0'
beq :- ; Branch always
; Call loader stub after C libary shutdown
: lda #<target
ldx #>target
sta done+1
stx done+2
; Initiate C libary shutdown
jmp _exit
.bss
level : .res 1
.rodata
; Read whole program file
source: jsr $BF00
.byte READ_CALL
.word read_param
bcs error
; Close program file
jsr $BF00
.byte CLOSE_CALL
.word close_param
bcs error
; Check for cmdline handling
lda $0100 ; Valid cmdline?
beq jump ; No, jump to program right away
ldx file_type ; SYS file?
bne system ; Yes, check for startup filename
; Store REM and cmdline in BASIC input buffer
lda #$B2 ; REM token
bne :++ ; Branch always
: inx
lda a:$0100-1,x
: sta $0200,x
bne :--
beq jump ; Branch always
; Check for startup filename support
; ProDOS TechRefMan, chapter 5.1.5.1:
; "$2000 is a jump instruction. $2003 and $2004 are $EE."
system: lda $2000
cmp #$4C
bne jump
lda $2003
cmp #$EE
bne jump
lda $2004
cmp #$EE
bne jump
; Store cmdline in startup filename buffer
ldx #$01
: lda a:$0100-1,x
beq :+
sta $2006,x
inx
cpx $2005 ; Buffer full?
bcc :- ; No, continue
: dex
stx $2006 ; Store cmdline length
; Go for it ...
jump: jmp (data_buffer)
file_type = * - source + target
.byte $00
read_param = * - source + target
.byte $04 ; PARAM_COUNT
read_ref = * - source + target
.byte $00 ; REF_NUM
data_buffer = * - source + target
.addr $2000 ; DATA_BUFFER
.word $FFFF ; REQUEST_COUNT
.word $0000 ; TRANS_COUNT
close_param = * - source + target
.byte $01 ; PARAM_COUNT
close_ref = * - source + target
.byte $00 ; REF_NUM
; Quit to ProDOS dispatcher
quit = * - source + target
error: jsr $BF00
.byte $65 ; QUIT
.word quit_param
quit_param = * - source + target
.byte $04 ; PARAM_COUNT
.byte $00 ; QUIT_TYPE
.word $0000 ; RESERVED
.byte $00 ; RESERVED
.word $0000 ; RESERVED
size = * - source
target = DOSWARM - size
dosvec: jmp quit