Use tmp1 instead of y register

popa clobbers y
2023-12-01 22:53:41 -08:00
parent e8452eb98c
commit de804ac3ca
1 changed files with 4 additions and 3 deletions
--- a/sw/kernel/devices/rtc.s
+++ b/sw/kernel/devices/rtc.s
@@ -93,12 +93,13 @@ IRQ_THRESHOLD_3     = $00

 ; void rtc_set(uint32_t val, uint8_t idx);
 .proc _rtc_set
-    tay             ; move cmd to Y
+    sta tmp1        ; store idx in tmp1
    ldx #$04
-L1: sty RTC_CMD     ; store cmd+idx to CMD    
+L1: lda tmp1
+    sta RTC_CMD     ; store cmd+idx to CMD    
    jsr popa        ; pop 1 byte of argument
    sta RTC_DAT     ; write it to data
-    iny             ; increase index
+    inc tmp1        ; increase index
    dex         
    bne L1          ; repeat 4 times
    rts