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cc65/libsrc/c64/settime.s
2018-11-06 11:13:23 +01:00

85 lines
1.8 KiB
ArmAsm

;
; Oliver Schmidt, 16.8.2018
;
; int __fastcall__ clock_settime (clockid_t clk_id, const struct timespec *tp);
;
.include "time.inc"
.include "c64.inc"
.importzp sreg, ptr1
.import pushax, pusheax, ldax0sp, ldeaxidx
.import tosdiveax, incsp3, return0
.import TM, load_tenth
;----------------------------------------------------------------------------
.code
.proc _clock_settime
jsr pushax
.assert timespec::tv_sec = 0, error
jsr _localtime
sta ptr1
stx ptr1+1
ldy #.sizeof(tm)-1
@L1: lda (ptr1),y
sta TM,y
dey
bpl @L1
lda TM + tm::tm_hour
jsr dec2BCD
tax ; Force flags
bne @L2
lda #$92 ; 12 AM
bne @L3
@L2: cmp #$13 ; 1 PM
bcc @L3
sed
sbc #$12
cld
ora #%10000000
@L3: sta CIA1_TODHR
lda TM + tm::tm_min
jsr dec2BCD
sta CIA1_TODMIN
lda TM + tm::tm_sec
jsr dec2BCD
sta CIA1_TODSEC
jsr ldax0sp
ldy #3+timespec::tv_nsec
jsr ldeaxidx
jsr pusheax
jsr load_tenth
jsr tosdiveax
sta CIA1_TOD10
jsr incsp3
jmp return0
.endproc
;----------------------------------------------------------------------------
; Just sum up the value in BCD mode.
; http://forum.6502.org/viewtopic.php?p=7629#p7629
.proc dec2BCD
tax
dex
bmi @L9
lda #0
clc
sed
@L1: adc #1
dex
bpl @L1
cld
@L9: rts
.endproc