Files
x86-bare-metal-examples/rtc.S
Ciro Santilli e0a2854087 link to examples from readme
Do another cleanup round while I'm at it.
2018-07-17 10:06:47 +01:00

63 lines
1.0 KiB
ArmAsm

/* TODO what do those numbers mean? Where is this all documented? */
.equ RTCaddress, 0x70
.equ RTCdata, 0x71
#include "common.h"
BEGIN
update_in_progress:
mov $10, %al
out %al, $RTCaddress
in $RTCdata, %al
testb $0x80, %al
jne update_in_progress
/* Second. */
mov $0, %al
out %al, $RTCaddress
in $RTCdata, %al
/* Only print if second changed. */
cmp %al, %cl
je update_in_progress
mov %al, %cl
PRINT_HEX <%al>
PUTC
/* Minute. */
mov $0x02, %al
out %al, $RTCaddress
in $RTCdata, %al
PRINT_HEX <%al>
PUTC
/* Hour. */
mov $0x04, %al
out %al, $RTCaddress
in $RTCdata, %al
PRINT_HEX <%al>
PUTC
/* Day. */
mov $0x07, %al
out %al, $RTCaddress
in $RTCdata, %al
PRINT_HEX <%al>
PUTC
/* Month. */
mov $0x08, %al
out %al, $RTCaddress
in $RTCdata, %al
PRINT_HEX <%al>
PUTC
/* Year. */
mov $0x09, %al
out %al, $RTCaddress
in $RTCdata, %al
PRINT_HEX <%al>
PRINT_NEWLINE
jmp update_in_progress