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Init rtc and pic in kernel

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Byron Lathi
2023-11-19 22:11:29 -08:00
parent 7f01b79abf
commit 680bccee62
5 changed files with 281 additions and 17 deletions
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78
sw/kernel/devices/rtc.s Normal file
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.MACPACK generic
.importzp tmp1
.export _init_rtc
.export _handle_rtc
RTC_CMD = $effe
RTC_DAT = $efff
RTC_THRESHOLD = $00
RTC_INCREMENT = $10
RTC_IRQ_THRESHOLD = $20
RTC_OUTPUT = $30
RTC_CONTROL = $30
; void init_rtc(void);
; Initialize rtc and generate 50ms interrupts
.proc _init_rtc
lda #RTC_INCREMENT+0 ; Set increment to 1
sta RTC_CMD
lda #$01
sta RTC_DAT
lda #RTC_INCREMENT+1
sta RTC_CMD
lda #$00
sta RTC_DAT
lda #RTC_INCREMENT+2
sta RTC_CMD
lda #$00
sta RTC_DAT
lda #RTC_INCREMENT+3
sta RTC_CMD
lda #$00
sta RTC_DAT
lda #RTC_THRESHOLD+0 ; Set threshold to 4000 ($fa0)
sta RTC_CMD
lda #$a0
sta RTC_DAT
lda #RTC_THRESHOLD+1
sta RTC_CMD
lda #$0f
sta RTC_DAT
lda #RTC_THRESHOLD+2
sta RTC_CMD
lda #$00
sta RTC_DAT
lda #RTC_THRESHOLD+3
sta RTC_CMD
lda #$00
sta RTC_DAT
lda #RTC_THRESHOLD+0 ; Set irq threshold to 50 ($32)
sta RTC_CMD
lda #$32
sta RTC_DAT
lda #RTC_THRESHOLD+1
sta RTC_CMD
lda #$00
sta RTC_DAT
lda #RTC_THRESHOLD+2
sta RTC_CMD
lda #$00
sta RTC_DAT
lda #RTC_THRESHOLD+3
sta RTC_CMD
lda #$00
sta RTC_DAT
rts
.endproc
.proc _handle_rtc
nop
rti
.endproc