prog8/compiler/res/prog8lib/atari/syslib.p8

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; Prog8 definitions for the Atari800XL
; Including memory registers, I/O registers, Basic and Kernal subroutines.
atari {
&uword NMI_VEC = $FFFA ; 6502 nmi vector, determined by the kernal if banked in
&uword RESET_VEC = $FFFC ; 6502 reset vector, determined by the kernal if banked in
&uword IRQ_VEC = $FFFE ; 6502 interrupt vector, determined by the kernal if banked in
; ---- kernal routines ----
; TODO
asmsub init_system() {
; Initializes the machine to a sane starting state.
; Called automatically by the loader program logic.
; TODO
%asm {{
sei
cld
clc
; TODO reset screen mode etc etc
clv
cli
rts
}}
}
asmsub init_system_phase2() {
%asm {{
rts ; no phase 2 steps on the Atari
}}
}
}
sys {
; ------- lowlevel system routines --------
const ubyte target = 8 ; compilation target specifier. 64 = C64, 128 = C128, 16 = CommanderX16, 8 = atari800XL
asmsub reset_system() {
; Soft-reset the system back to initial power-on Basic prompt.
; TODO
%asm {{
sei
jmp (atari.RESET_VEC)
}}
}
sub wait(uword jiffies) {
; --- wait approximately the given number of jiffies (1/60th seconds)
; TODO
}
asmsub waitvsync() clobbers(A) {
; --- busy wait till the next vsync has occurred (approximately), without depending on custom irq handling.
; TODO
%asm {{
nop
rts
}}
}
asmsub internal_stringcopy(uword source @R0, uword target @AY) clobbers (A,Y) {
; Called when the compiler wants to assign a string value to another string.
%asm {{
sta P8ZP_SCRATCH_W1
sty P8ZP_SCRATCH_W1+1
lda cx16.r0
ldy cx16.r0+1
jmp prog8_lib.strcpy
}}
}
asmsub memcopy(uword source @R0, uword target @R1, uword count @AY) clobbers(A,X,Y) {
2022-03-02 22:31:07 +00:00
; note: only works for NON-OVERLAPPING memory regions!
; note: can't be inlined because is called from asm as well
%asm {{
ldx cx16.r0
stx P8ZP_SCRATCH_W1 ; source in ZP
ldx cx16.r0+1
stx P8ZP_SCRATCH_W1+1
ldx cx16.r1
stx P8ZP_SCRATCH_W2 ; target in ZP
ldx cx16.r1+1
stx P8ZP_SCRATCH_W2+1
cpy #0
bne _longcopy
; copy <= 255 bytes
tay
bne _copyshort
rts ; nothing to copy
_copyshort
; decrease source and target pointers so we can simply index by Y
lda P8ZP_SCRATCH_W1
bne +
dec P8ZP_SCRATCH_W1+1
+ dec P8ZP_SCRATCH_W1
lda P8ZP_SCRATCH_W2
bne +
dec P8ZP_SCRATCH_W2+1
+ dec P8ZP_SCRATCH_W2
- lda (P8ZP_SCRATCH_W1),y
sta (P8ZP_SCRATCH_W2),y
dey
bne -
rts
_longcopy
sta P8ZP_SCRATCH_B1 ; lsb(count) = remainder in last page
tya
tax ; x = num pages (1+)
ldy #0
- lda (P8ZP_SCRATCH_W1),y
sta (P8ZP_SCRATCH_W2),y
iny
bne -
inc P8ZP_SCRATCH_W1+1
inc P8ZP_SCRATCH_W2+1
dex
bne -
ldy P8ZP_SCRATCH_B1
bne _copyshort
rts
}}
}
asmsub memset(uword mem @R0, uword numbytes @R1, ubyte value @A) clobbers(A,X,Y) {
%asm {{
ldy cx16.r0
sty P8ZP_SCRATCH_W1
ldy cx16.r0+1
sty P8ZP_SCRATCH_W1+1
ldx cx16.r1
ldy cx16.r1+1
jmp prog8_lib.memset
}}
}
asmsub memsetw(uword mem @R0, uword numwords @R1, uword value @AY) clobbers(A,X,Y) {
%asm {{
ldx cx16.r0
stx P8ZP_SCRATCH_W1
ldx cx16.r0+1
stx P8ZP_SCRATCH_W1+1
ldx cx16.r1
stx P8ZP_SCRATCH_W2
ldx cx16.r1+1
stx P8ZP_SCRATCH_W2+1
jmp prog8_lib.memsetw
}}
}
inline asmsub read_flags() -> ubyte @A {
%asm {{
php
pla
}}
}
inline asmsub clear_carry() {
%asm {{
clc
}}
}
inline asmsub set_carry() {
%asm {{
sec
}}
}
inline asmsub clear_irqd() {
%asm {{
cli
}}
}
inline asmsub set_irqd() {
%asm {{
sei
}}
}
inline asmsub exit(ubyte returnvalue @A) {
; -- immediately exit the program with a return code in the A register
; TODO
%asm {{
ldx prog8_lib.orig_stackpointer
txs
rts ; return to original caller
}}
}
inline asmsub progend() -> uword @AY {
%asm {{
lda #<prog8_program_end
ldy #>prog8_program_end
}}
}
}
cx16 {
; the sixteen virtual 16-bit registers that the CX16 has defined in the zeropage
; they are simulated on the Atari as well but their location in memory is different
; TODO
&uword r0 = $1b00
&uword r1 = $1b02
&uword r2 = $1b04
&uword r3 = $1b06
&uword r4 = $1b08
&uword r5 = $1b0a
&uword r6 = $1b0c
&uword r7 = $1b0e
&uword r8 = $1b10
&uword r9 = $1b12
&uword r10 = $1b14
&uword r11 = $1b16
&uword r12 = $1b18
&uword r13 = $1b1a
&uword r14 = $1b1c
&uword r15 = $1b1e
&word r0s = $1b00
&word r1s = $1b02
&word r2s = $1b04
&word r3s = $1b06
&word r4s = $1b08
&word r5s = $1b0a
&word r6s = $1b0c
&word r7s = $1b0e
&word r8s = $1b10
&word r9s = $1b12
&word r10s = $1b14
&word r11s = $1b16
&word r12s = $1b18
&word r13s = $1b1a
&word r14s = $1b1c
&word r15s = $1b1e
&ubyte r0L = $1b00
&ubyte r1L = $1b02
&ubyte r2L = $1b04
&ubyte r3L = $1b06
&ubyte r4L = $1b08
&ubyte r5L = $1b0a
&ubyte r6L = $1b0c
&ubyte r7L = $1b0e
&ubyte r8L = $1b10
&ubyte r9L = $1b12
&ubyte r10L = $1b14
&ubyte r11L = $1b16
&ubyte r12L = $1b18
&ubyte r13L = $1b1a
&ubyte r14L = $1b1c
&ubyte r15L = $1b1e
&ubyte r0H = $1b01
&ubyte r1H = $1b03
&ubyte r2H = $1b05
&ubyte r3H = $1b07
&ubyte r4H = $1b09
&ubyte r5H = $1b0b
&ubyte r6H = $1b0d
&ubyte r7H = $1b0f
&ubyte r8H = $1b11
&ubyte r9H = $1b13
&ubyte r10H = $1b15
&ubyte r11H = $1b17
&ubyte r12H = $1b19
&ubyte r13H = $1b1b
&ubyte r14H = $1b1d
&ubyte r15H = $1b1f
&byte r0sL = $1b00
&byte r1sL = $1b02
&byte r2sL = $1b04
&byte r3sL = $1b06
&byte r4sL = $1b08
&byte r5sL = $1b0a
&byte r6sL = $1b0c
&byte r7sL = $1b0e
&byte r8sL = $1b10
&byte r9sL = $1b12
&byte r10sL = $1b14
&byte r11sL = $1b16
&byte r12sL = $1b18
&byte r13sL = $1b1a
&byte r14sL = $1b1c
&byte r15sL = $1b1e
&byte r0sH = $1b01
&byte r1sH = $1b03
&byte r2sH = $1b05
&byte r3sH = $1b07
&byte r4sH = $1b09
&byte r5sH = $1b0b
&byte r6sH = $1b0d
&byte r7sH = $1b0f
&byte r8sH = $1b11
&byte r9sH = $1b13
&byte r10sH = $1b15
&byte r11sH = $1b17
&byte r12sH = $1b19
&byte r13sH = $1b1b
&byte r14sH = $1b1d
&byte r15sH = $1b1f
}