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cc65/libsrc/cbm610/systime.s
Greg King 0390c34e88 Changed multi-line C comments into another style.
The left side doesn't look unbalanced.
2014-06-30 16:51:07 -04:00

99 lines
2.2 KiB
ArmAsm

;
; Stefan Haubenthal, 2009-07-27
; Ullrich von Bassewitz, 2009-09-24
;
; time_t _systime (void);
; /* Similar to time(), but:
; ** - Is not ISO C
; ** - Does not take the additional pointer
; ** - Does not set errno when returning -1
; */
;
.include "time.inc"
.include "cbm610.inc"
.include "extzp.inc"
.import sys_bank, restore_bank
.importzp tmp1, tmp2
;----------------------------------------------------------------------------
.code
.proc __systime
; Switch to the system bank
jsr sys_bank
; Read the clock
ldy #CIA::TODHR
lda (cia),y
bpl AM
and #%01111111
sed
clc
adc #$12
cld
AM: jsr BCD2dec
sta TM + tm::tm_hour
ldy #CIA::TODMIN
lda (cia),y
jsr BCD2dec
sta TM + tm::tm_min
ldy #CIA::TODSEC
lda (cia),y
jsr BCD2dec
sta TM + tm::tm_sec
ldy #CIA::TOD10
lda (cia),y ; Dummy read to unfreeze
; Restore the bank
jsr restore_bank
; Convert to a time
lda #<TM
ldx #>TM
jmp _mktime
.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
;----------------------------------------------------------------------------
; TM struct with date set to 1970-01-01
.data
TM: .word 0 ; tm_sec
.word 0 ; tm_min
.word 0 ; tm_hour
.word 1 ; tm_mday
.word 0 ; tm_mon
.word 70 ; tm_year
.word 0 ; tm_wday
.word 0 ; tm_yday
.word 0 ; tm_isdst