prog8/il65/lib/il65lib.ill
2018-01-15 00:46:27 +01:00

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; IL65 internal library routines - always included by the compiler
;
; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
;
; indent format: TABS, size=8
~ il65_lib {
; note: the following ZP scratch registers must be the same as in c64lib
memory .byte SCRATCH_ZP1 = $02 ; scratch register #1 in ZP
memory .byte SCRATCH_ZP2 = $03 ; scratch register #2 in ZP
memory .word SCRATCH_ZPWORD1 = $fb ; scratch word in ZP ($fb/$fc)
memory .word SCRATCH_ZPWORD2 = $fd ; scratch word in ZP ($fd/$fe)
%asm {
; ---- jmp (indirect) routines for register pairs containing the indirect address
jsr_indirect_nozpuse_AX
sta jsr_indirect_tmp
stx jsr_indirect_tmp+1
jmp (jsr_indirect_tmp)
jsr_indirect_nozpuse_AY
sta jsr_indirect_tmp
sty jsr_indirect_tmp+1
jmp (jsr_indirect_tmp)
jsr_indirect_nozpuse_XY
stx jsr_indirect_tmp
sty jsr_indirect_tmp+1
jmp (jsr_indirect_tmp)
jsr_indirect_tmp
.byte 0, 0
jsr_indirect_AX
sta SCRATCH_ZP1
stx SCRATCH_ZP2
jmp (SCRATCH_ZP1)
jsr_indirect_AY
sta SCRATCH_ZP1
sty SCRATCH_ZP2
jmp (SCRATCH_ZP1)
jsr_indirect_XY
stx SCRATCH_ZP1
sty SCRATCH_ZP2
jmp (SCRATCH_ZP1)
; copy memory UP from (SCRATCH_ZPWORD1) to (SCRATCH_ZPWORD2) of length X/Y (16-bit, X=lo, Y=hi)
; clobbers register A,X,Y
memcopy16_up
source = SCRATCH_ZPWORD1
dest = SCRATCH_ZPWORD2
length = SCRATCH_ZP1 ; (and SCRATCH_ZP2)
stx length
sty length+1
ldx length ; move low byte of length into X
bne + ; jump to start if X > 0
dec length ; subtract 1 from length
+ ldy #0 ; set Y to 0
- lda (source),y ; set A to whatever (source) points to offset by Y
sta (dest),y ; move A to location pointed to by (dest) offset by Y
iny ; increment Y
bne + ; if Y<>0 then (rolled over) then still moving bytes
inc source+1 ; increment hi byte of source
inc dest+1 ; increment hi byte of dest
+ dex ; decrement X (lo byte counter)
bne - ; if X<>0 then move another byte
dec length ; weve moved 255 bytes, dec length
bpl - ; if length is still positive go back and move more
rts ; done
; copy memory UP from (SCRATCH_ZPWORD1) to (AY) with length X (1 to 256, 0 meaning 256)
; destination must not overlap, or be before start, then overlap is possible.
; clobbers A, X, Y
memcopy
sta SCRATCH_ZPWORD2
sty SCRATCH_ZPWORD2+1
ldy #0
- lda (SCRATCH_ZPWORD1), y
sta (SCRATCH_ZPWORD2), y
iny
dex
bne -
rts
; fill memory from (SCRATCH_ZPWORD1), length XY, with value in A.
; clobbers X, Y
memset stx SCRATCH_ZP1
sty SCRATCH_ZP2
ldy #0
ldx SCRATCH_ZP2
beq _lastpage
_fullpage sta (SCRATCH_ZPWORD1),y
iny
bne _fullpage
inc SCRATCH_ZPWORD1+1 ; next page
dex
bne _fullpage
_lastpage ldy SCRATCH_ZP1
beq +
- dey
sta (SCRATCH_ZPWORD1),y
bne -
+ rts
; fill memory from (SCRATCH_ZPWORD1) number of words in SCRATCH_ZPWORD2, with word value in AY.
; clobbers A, X, Y
memsetw
sta _mod1+1 ; self-modify
sty _mod1b+1 ; self-modify
sta _mod2+1 ; self-modify
sty _mod2b+1 ; self-modify
ldx SCRATCH_ZPWORD1
stx SCRATCH_ZP1
ldx SCRATCH_ZPWORD1+1
inx
stx SCRATCH_ZP2 ; second page
ldy #0
ldx SCRATCH_ZPWORD2+1
beq _lastpage
_fullpage
_mod1 lda #0 ; self-modified
sta (SCRATCH_ZPWORD1),y ; first page
sta (SCRATCH_ZP1),y ; second page
iny
_mod1b lda #0 ; self-modified
sta (SCRATCH_ZPWORD1),y ; first page
sta (SCRATCH_ZP1),y ; second page
iny
bne _fullpage
inc SCRATCH_ZPWORD1+1 ; next page pair
inc SCRATCH_ZPWORD1+1 ; next page pair
inc SCRATCH_ZP1+1 ; next page pair
inc SCRATCH_ZP1+1 ; next page pair
dex
bne _fullpage
_lastpage ldx SCRATCH_ZPWORD2
beq _done
ldy #0
-
_mod2 lda #0 ; self-modified
sta (SCRATCH_ZPWORD1), y
inc SCRATCH_ZPWORD1
bne _mod2b
inc SCRATCH_ZPWORD1+1
_mod2b lda #0 ; self-modified
sta (SCRATCH_ZPWORD1), y
inc SCRATCH_ZPWORD1
bne +
inc SCRATCH_ZPWORD1+1
+ dex
bne -
_done rts
}
%noreturn
}