; 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 ; @todo still needed?? 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 ; increments/decrements a byte referenced by indirect register pair by 1 ; clobbers A/Y, Carry flag determines incr or decr incrdecr_deref_byte_reg_AX sta SCRATCH_ZPWORD1 stx SCRATCH_ZPWORD1+1 bcc incr_deref_byte bcs decr_deref_byte incrdecr_deref_byte_reg_AY sta SCRATCH_ZPWORD1 sty SCRATCH_ZPWORD1+1 bcc incr_deref_byte bcs decr_deref_byte incrdecr_deref_byte_reg_XY stx SCRATCH_ZPWORD1 sty SCRATCH_ZPWORD1+1 bcs decr_deref_byte incr_deref_byte ldy #0 lda (SCRATCH_ZPWORD1), y adc #1 ; carry's cleared already sta (SCRATCH_ZPWORD1), y rts decr_deref_byte ldy #0 lda (SCRATCH_ZPWORD1), y sbc #1 ; carry's set already sta (SCRATCH_ZPWORD1), y rts ; increments/decrements a word referenced by indirect register pair by 1 ; clobbers A/Y, Carry flag determines incr or decr incrdecr_deref_word_reg_AX sta SCRATCH_ZPWORD1 stx SCRATCH_ZPWORD1+1 bcc incr_deref_word bcs decr_deref_word incrdecr_deref_word_reg_AY sta SCRATCH_ZPWORD1 sty SCRATCH_ZPWORD1+1 bcc incr_deref_word bcs decr_deref_word incrdecr_deref_word_reg_XY stx SCRATCH_ZPWORD1 sty SCRATCH_ZPWORD1+1 bcs decr_deref_word incr_deref_word ldy #0 lda (SCRATCH_ZPWORD1), y adc #1 ; carry's cleared already sta (SCRATCH_ZPWORD1), y bcc + iny lda (SCRATCH_ZPWORD1), y adc #0 ; carry is set sta (SCRATCH_ZPWORD1), y + rts decr_deref_word ldy #0 lda (SCRATCH_ZPWORD1), y bne + pha iny lda (SCRATCH_ZPWORD1), y sbc #1 ; carry's set already sta (SCRATCH_ZPWORD1), y dey pla + sec sbc #1 sta (SCRATCH_ZPWORD1), y rts ; shift bits in A right by X positions lsr_A_by_X cpx #8 bcc _shift lda #0 ; x >=8, result always 0 rts _shift cpx #0 beq + - lsr a dex bne - + rts ; shift bits in A left by X positions asl_A_by_X cpx #8 bcc _shift lda #0 ; x >=8, result always 0 rts _shift cpx #0 beq + - asl a dex bne - + rts }} }