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prog8/compiler/res/prog8lib/pet32/syslib.p8
Irmen de Jong 2d7ebff8e9 fix shadowing warnings in asm and library code
2023-08-29 11:00:53 +02:00

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; Prog8 definitions for the Commodore PET
; Including memory registers, I/O registers, Basic and Kernal subroutines.
; see: https://www.pagetable.com/?p=926 , http://www.zimmers.net/cbmpics/cbm/PETx/petmem.txt
cbm {
; Commodore (CBM) common variables, vectors and kernal routines
%option no_symbol_prefixing
&ubyte TIME_HI = $8d ; software jiffy clock, hi byte
&ubyte TIME_MID = $8e ; .. mid byte
&ubyte TIME_LO = $8f ; .. lo byte. Updated by IRQ every 1/60 sec
&ubyte STATUS = $96 ; kernal status variable for I/O
&uword CINV = $0090 ; IRQ vector (in ram)
&uword CBINV = $0092 ; BRK vector (in ram)
&uword NMINV = $0094 ; NMI vector (in ram)
&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
; the default addresses for the character screen chars and colors
const uword Screen = $8000 ; to have this as an array[40*25] the compiler would have to support array size > 255
romsub $FFC6 = CHKIN(ubyte logical @ X) clobbers(A,X) -> bool @Pc ; define an input channel
romsub $FFC9 = CHKOUT(ubyte logical @ X) clobbers(A,X) ; define an output channel
romsub $FFCC = CLRCHN() clobbers(A,X) ; restore default devices
romsub $FFCF = CHRIN() clobbers(X, Y) -> ubyte @ A ; input a character (for keyboard, read a whole line from the screen) A=byte read.
romsub $FFD2 = CHROUT(ubyte character @ A) ; output a character
romsub $FFE1 = STOP() clobbers(X) -> bool @ Pz, ubyte @ A ; check the STOP key (and some others in A)
romsub $FFE4 = GETIN() clobbers(X,Y) -> bool @Pc, ubyte @ A ; get a character
romsub $FFE7 = CLALL() clobbers(A,X) ; close all files
romsub $FFEA = UDTIM() clobbers(A,X) ; update the software clock
asmsub STOP2() clobbers(X) -> ubyte @A {
; -- check if STOP key was pressed, returns true if so. More convenient to use than STOP() because that only sets the carry status flag.
%asm {{
jsr cbm.STOP
beq +
lda #0
rts
+ lda #1
rts
}}
}
asmsub SETTIM(ubyte low @ A, ubyte middle @ X, ubyte high @ Y) {
; PET stub to set the software clock
%asm {{
sty TIME_HI
stx TIME_MID
sta TIME_LO
rts
}}
}
asmsub RDTIM() -> ubyte @ A, ubyte @ X, ubyte @ Y {
; PET stub to read the software clock (A=lo,X=mid,Y=high)
%asm {{
ldy TIME_HI
ldx TIME_MID
lda TIME_LO
rts
}}
}
asmsub RDTIM16() clobbers(X) -> uword @AY {
; -- like RDTIM() but only returning the lower 16 bits in AY for convenience
%asm {{
lda TIME_LO
ldy TIME_MID
rts
}}
}
}
sys {
; ------- lowlevel system routines --------
%option no_symbol_prefixing
const ubyte target = 32 ; compilation target specifier. 64 = C64, 128 = C128, 16 = CommanderX16, 32=PET
asmsub init_system() {
; Initializes the machine to a sane starting state.
; Called automatically by the loader program logic.
; Uppercase charset is activated.
%asm {{
sei
cld
lda #142
jsr cbm.CHROUT ; uppercase
lda #147
jsr cbm.CHROUT ; clear screen
clc
clv
cli
rts
}}
}
asmsub init_system_phase2() {
%asm {{
rts ; no phase 2 steps on the PET
}}
}
asmsub cleanup_at_exit() {
; executed when the main subroutine does rts
%asm {{
rts
}}
}
asmsub reset_system() {
; Soft-reset the system back to initial power-on Basic prompt.
%asm {{
sei
jmp (cbm.RESET_VEC)
}}
}
asmsub waitvsync() clobbers(A) {
; --- busy wait till the next vsync has occurred (approximately), without depending on custom irq handling.
; Note: on PET this simply waits until the next jiffy clock update, I don't know if a true vsync is possible there
%asm {{
lda #1
ldy #0
jmp wait
}}
}
asmsub wait(uword jiffies @AY) {
; --- wait approximately the given number of jiffies (1/60th seconds) (N or N+1)
; note: the system irq handler has to be active for this to work as it depends on the system jiffy clock
%asm {{
stx P8ZP_SCRATCH_B1
sta P8ZP_SCRATCH_W1
sty P8ZP_SCRATCH_W1+1
_loop lda P8ZP_SCRATCH_W1
ora P8ZP_SCRATCH_W1+1
bne +
ldx P8ZP_SCRATCH_B1
rts
+ lda cbm.TIME_LO
sta P8ZP_SCRATCH_B1
- lda cbm.TIME_LO
cmp P8ZP_SCRATCH_B1
beq -
lda P8ZP_SCRATCH_W1
bne +
dec P8ZP_SCRATCH_W1+1
+ dec P8ZP_SCRATCH_W1
jmp _loop
}}
}
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) {
; 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 irqsafe_set_irqd() {
%asm {{
php
sei
}}
}
inline asmsub irqsafe_clear_irqd() {
%asm {{
plp
}}
}
inline asmsub exit(ubyte returnvalue @A) {
; -- immediately exit the program with a return code in the A register
%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 {
%option no_symbol_prefixing
; the sixteen virtual 16-bit registers that the CX16 has defined in the zeropage
; they are simulated on the PET as well but their location in memory is different
; (because there's no room for them in the zeropage)
; we select the top page of RAM (assume 32Kb)
&uword r0 = $7fe0
&uword r1 = $7fe2
&uword r2 = $7fe4
&uword r3 = $7fe6
&uword r4 = $7fe8
&uword r5 = $7fea
&uword r6 = $7fec
&uword r7 = $7fee
&uword r8 = $7ff0
&uword r9 = $7ff2
&uword r10 = $7ff4
&uword r11 = $7ff6
&uword r12 = $7ff8
&uword r13 = $7ffa
&uword r14 = $7ffc
&uword r15 = $7ffe
&word r0s = $7fe0
&word r1s = $7fe2
&word r2s = $7fe4
&word r3s = $7fe6
&word r4s = $7fe8
&word r5s = $7fea
&word r6s = $7fec
&word r7s = $7fee
&word r8s = $7ff0
&word r9s = $7ff2
&word r10s = $7ff4
&word r11s = $7ff6
&word r12s = $7ff8
&word r13s = $7ffa
&word r14s = $7ffc
&word r15s = $7ffe
&ubyte r0L = $7fe0
&ubyte r1L = $7fe2
&ubyte r2L = $7fe4
&ubyte r3L = $7fe6
&ubyte r4L = $7fe8
&ubyte r5L = $7fea
&ubyte r6L = $7fec
&ubyte r7L = $7fee
&ubyte r8L = $7ff0
&ubyte r9L = $7ff2
&ubyte r10L = $7ff4
&ubyte r11L = $7ff6
&ubyte r12L = $7ff8
&ubyte r13L = $7ffa
&ubyte r14L = $7ffc
&ubyte r15L = $7ffe
&ubyte r0H = $7fe1
&ubyte r1H = $7fe3
&ubyte r2H = $7fe5
&ubyte r3H = $7fe7
&ubyte r4H = $7fe9
&ubyte r5H = $7feb
&ubyte r6H = $7fed
&ubyte r7H = $7fef
&ubyte r8H = $7ff1
&ubyte r9H = $7ff3
&ubyte r10H = $7ff5
&ubyte r11H = $7ff7
&ubyte r12H = $7ff9
&ubyte r13H = $7ffb
&ubyte r14H = $7ffd
&ubyte r15H = $7fff
&byte r0sL = $7fe0
&byte r1sL = $7fe2
&byte r2sL = $7fe4
&byte r3sL = $7fe6
&byte r4sL = $7fe8
&byte r5sL = $7fea
&byte r6sL = $7fec
&byte r7sL = $7fee
&byte r8sL = $7ff0
&byte r9sL = $7ff2
&byte r10sL = $7ff4
&byte r11sL = $7ff6
&byte r12sL = $7ff8
&byte r13sL = $7ffa
&byte r14sL = $7ffc
&byte r15sL = $7ffe
&byte r0sH = $7fe1
&byte r1sH = $7fe3
&byte r2sH = $7fe5
&byte r3sH = $7fe7
&byte r4sH = $7fe9
&byte r5sH = $7feb
&byte r6sH = $7fed
&byte r7sH = $7fef
&byte r8sH = $7ff1
&byte r9sH = $7ff3
&byte r10sH = $7ff5
&byte r11sH = $7ff7
&byte r12sH = $7ff9
&byte r13sH = $7ffb
&byte r14sH = $7ffd
&byte r15sH = $7fff
asmsub save_virtual_registers() clobbers(A,Y) {
%asm {{
ldy #31
- lda cx16.r0,y
sta _cx16_vreg_storage,y
dey
bpl -
rts
_cx16_vreg_storage
.word 0,0,0,0,0,0,0,0
.word 0,0,0,0,0,0,0,0
}}
}
asmsub restore_virtual_registers() clobbers(A,Y) {
%asm {{
ldy #31
- lda save_virtual_registers._cx16_vreg_storage,y
sta cx16.r0,y
dey
bpl -
rts
}}
}
}
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