From 6f1b50a4cc6c232ee505a543f006abb1c6cd33cf Mon Sep 17 00:00:00 2001
From: Benji Dial <benji6283@gmail.com>
Date: Fri, 19 Feb 2021 23:41:56 -0500
Subject: rtc fixes, time command

---
 src/kernel/cmos.c | 18 +++++++++++++-----
 src/kernel/cmos.h |  1 +
 src/kernel/main.c |  1 +
 3 files changed, 15 insertions(+), 5 deletions(-)

(limited to 'src/kernel')

diff --git a/src/kernel/cmos.c b/src/kernel/cmos.c
index 39f7c4f..1a95805 100644
--- a/src/kernel/cmos.c
+++ b/src/kernel/cmos.c
@@ -3,9 +3,22 @@
 
 static inline uint8_t read_cmos(uint8_t reg) {
   outb(0x0070, reg);
+  for (uint32_t i = 0; i < 1000000; ++i)
+    ;//spin
   return inb(0x0071);
 }
 
+static inline void write_cmos(uint8_t reg, uint8_t value) {
+  outb(0x0070, reg);
+  for (uint32_t i = 0; i < 1000000; ++i)
+    ;//spin
+  outb(0x0071, value);
+}
+
+void cmos_init() {
+  write_cmos(0x0b, read_cmos(0x0b) | 0x06);
+}
+
 //The idea of reading until you get the same value twice, and checking the status register
 //  is from the OSDev Wiki page at <https://wiki.osdev.org/CMOS#The_Real-Time_Clock>.
 struct rtc_time get_rtc_time() {
@@ -21,11 +34,6 @@ get_sec:
   }
   ret.minutes      = read_cmos(0x02);
   ret.hours        = read_cmos(0x04);
-  if (ret.hours & 0x80) {
-    ret.hours -= 0x80 - 12;
-    if (ret.hours == 24)
-      ret.hours = 0;
-  }
   ret.day_of_week  = read_cmos(0x06);
   ret.day_of_month = read_cmos(0x07);
   ret.month        = read_cmos(0x08);
diff --git a/src/kernel/cmos.h b/src/kernel/cmos.h
index 53ec398..515de1d 100644
--- a/src/kernel/cmos.h
+++ b/src/kernel/cmos.h
@@ -14,5 +14,6 @@ struct rtc_time {
 };
 
 struct rtc_time get_rtc_time();
+void cmos_init();
 
 #endif
\ No newline at end of file
diff --git a/src/kernel/main.c b/src/kernel/main.c
index 7e49049..36b5fc1 100644
--- a/src/kernel/main.c
+++ b/src/kernel/main.c
@@ -23,6 +23,7 @@ void _start_user_mode() __attribute__ ((noreturn));
 
 __attribute__ ((noreturn))
 void main() {
+  cmos_init();
   init_pagemap();
   init_paging();
   init_tasks();
-- 
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