Add rtc_set

2023-12-01 08:28:38 -08:00
parent 2cdd260a87
commit e8452eb98c
3 changed files with 27 additions and 0 deletions
--- a/sw/kernel/devices/rtc.s
+++ b/sw/kernel/devices/rtc.s
@@ -2,8 +2,11 @@

 .importzp tmp1

+.import popa
+
 .export _init_rtc
 .export _handle_rtc
+.export _rtc_set

 RTC_CMD = $effe
 RTC_DAT = $efff
@@ -86,7 +89,19 @@ IRQ_THRESHOLD_3     = $00
    sta RTC_DAT
    
    rts
+.endproc

+; void rtc_set(uint32_t val, uint8_t idx);
+.proc _rtc_set
+    tay             ; move cmd to Y
+    ldx #$04
+L1: sty RTC_CMD     ; store cmd+idx to CMD    
+    jsr popa        ; pop 1 byte of argument
+    sta RTC_DAT     ; write it to data
+    iny             ; increase index
+    dex         
+    bne L1          ; repeat 4 times
+    rts
 .endproc