;
-; Atari XL startup system check
+; Atari startup system check
;
; This routine gets loaded prior to the main part of the executable
; and checks if the system is compatible to run the program.
-; It checks whether the system is an XL type one and that enough
-; memory is installed (which isn't the case for a 600XL).
-; If the system doesn't qualify, the loading of the main program
+; For the XL target it checks whether the system is an XL type one
+; and that enough memory is installed (which isn't the case for a 600XL).
+; For the non-XL target it checks whether there is enough memory
+; installed to run the program.
+; For both targets it checks that the program won't load below MEMLO.
+; If one of the checks fails, the loading of the main program
; is aborted by jumping to DOSVEC.
;
; Christian Groessler, chris@groessler.org, 2013
;
-DEBUG = 1
+;DEBUG = 1
-.if .defined(__ATARIXL__)
+ .export __SYSTEM_CHECK__, __SYSCHK_END__
+ .import __STARTADDRESS__
- .export syschk
- .import __SYSCHK_LOAD__
- .import __SAVEAREA_LOAD__
+ ; the following imports are only needed for the 'atari' target version
+ .import __BSS_SIZE__, __BSS_RUN__
+ .import __STACKSIZE__
+ .import __RESERVED_MEMORY__
+
+ ; import our header and trailers
+ .forceimport __SYSCHKHDR__, __SYSCHKTRL__
.include "zeropage.inc"
.include "atari.inc"
-
.macro print_string text
- .local start, cont
- jmp cont
-start: .byte text, ATEOL
-cont: ldx #0 ; channel 0
- lda #<start
- sta ICBAL,x ; address
- lda #>start
- sta ICBAH,x
- lda #<(cont - start)
- sta ICBLL,x ; length
- lda #>(cont - start)
- sta ICBLH,x
- lda #PUTCHR
- sta ICCOM,x
- jsr CIOV_org
+ .local start, cont
+ jmp cont
+start: .byte text, ATEOL
+cont: ldx #0 ; channel 0
+ lda #<start
+ sta ICBAL,x ; address
+ lda #>start
+ sta ICBAH,x
+ lda #<(cont - start)
+ sta ICBLL,x ; length
+ lda #>(cont - start)
+ sta ICBLH,x
+ lda #PUTCHR
+ sta ICCOM,x
+ jsr CIOV_org
.endmacro
-.macro print_string2 addr, len
-
- ldx #0 ; channel 0
- lda #<addr
- sta ICBAL,x ; address
- lda #>addr
- sta ICBAH,x
- lda #<len
- sta ICBLL,x ; length
- lda #>len
- sta ICBLH,x
- lda #PUTCHR
- sta ICCOM,x
- jsr CIOV_org
+.macro print_string2 addr, len
+ ldx #0 ; channel 0
+ lda #<addr
+ sta ICBAL,x ; address
+ lda #>addr
+ sta ICBAH,x
+ lda #<len
+ sta ICBLL,x ; length
+ lda #>len
+ sta ICBLH,x
+ lda #PUTCHR
+ sta ICCOM,x
+ jsr CIOV_org
.endmacro
; ------------------------------------------------------------------------
-; Chunk header
+; code
-.segment "SYSCHKHDR"
+.segment "SYSCHK"
- .word __SYSCHK_LOAD__
- .word trailer - 1
+ rts ; for older DOSes which unconditionally run the first load chunk
+
+.ifdef __ATARIXL__
+
+; check for SpartaDOS and its usage of RAM below ROM
+; return CF 0/1 for ok/bad
+sdcheck:lda DOS
+ cmp #'S'
+ bne sdcrts0 ; not SpartaDOS, assume RAM is not used
+
+; check for BW-DOS, which always reports itself as SpartaDOS, but doesn't use memory under the ROM
+ lda DOS+3 ; 'B' in BW-DOS
+ cmp #'B'
+ bne sdnobw
+ lda DOS+4 ; 'W' in BW-DOS
+ cmp #'W'
+ beq sdcrts0 ; BW-DOS does not use RAM below ROM
+
+sdnobw: lda DOS+1 ; SD version
+ cmp #$40 ; SD-X has $40 or higher
+ bcc sdcrts1 ; older versions (except maybe 1.x) always use the RAM under the ROM
+ ldy #31 ; offset for OSRMFLG
+ lda (DOSVEC),y ; get OSRMFLG
+ bne sdcrts1
+
+sdcrts0:clc
+ rts
+sdcrts1:sec
+ rts
+
+ramrom_txt:
+ .byte "Memory under ROM is in use.", ATEOL
+ .byte "Cannot run this program.", ATEOL
+ramrom_txt_len = * - ramrom_txt
+
+lmemerrxl_txt:
+ .byte "Not enough memory to move screen", ATEOL
+ .byte "memory to low memory. Consider using", ATEOL
+ .byte "a higher load address.", ATEOL
+lmemerrxl_txt_len = * - lmemerrxl_txt
-; ------------------------------------------------------------------------
-; Actual code
+; no XL machine
+no_xl: print_string "This program needs an XL machine."
+ jmp fail
-.segment "SYSCHK"
-syschk:
- lda $fcd8 ; from ostype.s
- cmp #$a2
- bne is_xl
+; ***** entry point (atarixl) *****
-; no XL machine
- print_string "This program needs an XL machine."
- jmp fail
+syschk: lda $fcd8 ; from ostype.s
+ cmp #$a2
+ beq no_xl
; we have an XL machine, now check memory
-is_xl: lda RAMSIZ
- cmp #$80
- bcs sys_ok
+ lda RAMSIZ
+ cmp #$80
+ bcs sys_ok
-; not enough memory
- print_string "Not enough memory."
-fail: jsr delay
- jmp (DOSVEC)
+ jmp mem_err
+
+sys_ok: jsr sdcheck ; check for SpartaDOS-X, and if found, whether it uses the RAM under the ROM
+ bcc sd_ok
+ print_string2 ramrom_txt, ramrom_txt_len
+ jmp fail
-sys_ok:
- .include "xlmemchk.inc" ; calculate lowest address we will use when we move the screen buffer down
+sd_ok: .include "xlmemchk.inc" ; calculate lowest address we will use when we move the screen buffer down
- sec
- lda MEMLO
- sbc lowadr
- lda MEMLO+1
- sbc lowadr+1
- bcc memlo_ok
+ lda MEMLO
+ cmp lowadr
+ lda MEMLO+1
+ sbc lowadr+1
+ bcc memlo_ok
; load address was too low
- print_string2 lmemerr_txt, lmemerr_txt_len
- jsr delay ; long text takes longer to read, give user additional time
- jmp fail
+ print_string2 lmemerrxl_txt, lmemerrxl_txt_len
+ jsr delay ; long text takes longer to read, give user additional time
+ jmp fail
+
+.else ; above 'atarixl', below 'atari'
+
+.define CIOV_org CIOV ; the print_string macros use CIOV_org, map this to CIOV
+
+lmemerr_txt:
+ .byte "Program would load below MEMLO.", ATEOL
+ .byte "Consider using a higher load address.", ATEOL
+lmemerr_txt_len = * - lmemerr_txt
+
+
+; ***** entry point (atari) *****
+
+syschk:
+ sec
+ lda MEMTOP
+ sbc #<__RESERVED_MEMORY__
+ sta tmp
+ lda MEMTOP+1
+ sbc #>__RESERVED_MEMORY__
+ sta tmp+1
+ lda tmp
+ sec
+ sbc #<__STACKSIZE__
+ sta tmp
+ lda tmp+1
+ sbc #>__STACKSIZE__
+ sta tmp+1
+
+;tmp contains address which must be above .bss's end
+
+ lda tmp
+ cmp #<(__BSS_RUN__ + __BSS_SIZE__)
+ lda tmp+1
+ sbc #>(__BSS_RUN__ + __BSS_SIZE__)
+
+ bcc mem_err ; program doesn't fit into memory
+
+ lda MEMLO
+ cmp #<__STARTADDRESS__
+ lda MEMLO+1
+ sbc #>__STARTADDRESS__
+ bcc memlo_ok
+
+; load address was too low
+ print_string2 lmemerr_txt, lmemerr_txt_len
+ jsr delay ; long text takes longer to read, give user additional time
+ jmp fail
+
+.endif
; all is well(tm), launch the application
memlo_ok:
.ifdef DEBUG
- print_string "Stage #1 OK"
- jsr delay
+ print_string "Stage #1 OK"
+ jsr delay
.endif
- rts
-
-
-lmemerr_txt:
- .byte "Not enough memory to move screen", ATEOL
- .byte "memory to low memory. Consider using", ATEOL
- .byte "a higher load address.", ATEOL
-lmemerr_txt_len = * - lmemerr_txt
+ rts
+; not enough memory
+mem_err:print_string "Not enough memory."
+fail: jsr delay
+ jmp (DOSVEC)
; short delay
-.proc delay
-
- lda #10
-l: jsr delay1
- clc
- sbc #0
- bne l
- rts
-
-delay1: ldx #0
- ldy #0
-loop: dey
- bne loop
- dex
- bne loop
- rts
+.proc delay
+
+ lda #10
+@loop: jsr delay1
+ clc
+ sbc #0
+ bne @loop
+ rts
+
+delay1: ldx #0
+ ldy #0
+@loop: dey
+ bne @loop
+ dex
+ bne @loop
+ rts
.endproc
-; ------------------------------------------------------------------------
-; Chunk "trailer" - sets INITAD
+__SYSTEM_CHECK__=syschk
+__SYSCHK_END__:
-trailer:
- .word INITAD
- .word INITAD+1
- .word __SYSCHK_LOAD__
+.ifndef __ATARIXL__
+tmp: ; outside of the load chunk, some kind of poor man's .bss
+.endif
-.endif ; .if .defined(__ATARIXL__)
projects / cc65 / blobdiff