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

84 lines
1.9 KiB
ArmAsm

;
; Stefan Haubenthal, 27.7.2009
; Oliver Schmidt, 14.8.2018
;
; int __fastcall__ clock_gettime (clockid_t clk_id, struct timespec *tp);
;
.include "time.inc"
.include "c64.inc"
.importzp sreg, tmp1, tmp2
.import pushax, pusheax, tosmul0ax, steaxspidx, incsp1, return0
.import TM, load_tenth
;----------------------------------------------------------------------------
.code
.proc _clock_gettime
jsr pushax
jsr pushax
lda CIA1_TODHR
sed
tax ; Save PM flag
and #%01111111
cmp #$12 ; 12 AM/PM
bcc @L1
sbc #$12
@L1: inx ; Get PM flag
bpl @L2
clc
adc #$12
@L2: cld
jsr BCD2dec
sta TM + tm::tm_hour
lda CIA1_TODMIN
jsr BCD2dec
sta TM + tm::tm_min
lda CIA1_TODSEC
jsr BCD2dec
sta TM + tm::tm_sec
lda #<TM
ldx #>TM
jsr _mktime
ldy #timespec::tv_sec
jsr steaxspidx ; Pops address pushed by 2. pushax
jsr load_tenth
jsr pusheax
lda CIA1_TOD10
ldx #>$0000
jsr tosmul0ax
ldy #timespec::tv_nsec
jsr steaxspidx ; Pops address pushed by 1. pushax
jsr incsp1
jmp return0
.endproc
;----------------------------------------------------------------------------
; dec = (((BCD>>4)*10) + (BCD&0xf))
.proc BCD2dec
tax
and #%00001111
sta tmp1
txa
and #%11110000 ; *16
lsr ; *8
sta tmp2
lsr
lsr ; *2
adc tmp2 ; = *10
adc tmp1
rts
.endproc