Added Real Time Clock. Time is now being shown at the top

2024-05-08 16:54:25 +02:00
parent a97ac11d70
commit daa6d35045
5 changed files with 167 additions and 12 deletions
@@ -0,0 +1,148 @@
+#ifndef RTC_H
+#define RTC_H
+
+#include <interrupt/pic.h>
+#include <interrupt/idt.h>
+#include <screen/text.h>
+#include <stdbool.h>
+#include <string.h>
+
+#define CMOS_ADDRESS 0x70
+#define CMOS_DATA    0x71
+
+typedef struct {
+    uint8_t second;
+    uint8_t minute;
+    uint8_t hour;
+    uint8_t day;
+    uint8_t month;
+    uint16_t year;
+} __attribute__ ((packed)) datetime_t;
+
+static datetime_t* datetime = (datetime_t*)0x2000; // TODO: Put this at a constant address in memory
+
+bool cmosUpdateProgress() {
+    outb(CMOS_ADDRESS, 0x8a); // Read status reg A, disable NMI
+    return inb(CMOS_DATA) & 0x80;
+}
+
+uint8_t getRtcRegister(uint8_t reg) {
+    outb(CMOS_ADDRESS, reg | 0x80); // Disable NMI when sending
+    return inb(CMOS_DATA);
+}
+
+void enableRtc() {
+    uint8_t regB = getRtcRegister(0x0b);
+    outb(CMOS_ADDRESS, 0x8b);
+    outb(CMOS_DATA, regB | 0x40); // Set bit 6 - periodic int at 1024Hz
+    
+    getRtcRegister(0x0c); // Clear pending interrupts
+}
+
+void disableRtc() {
+    __asm__ volatile ("cli");
+    uint8_t regB = getRtcRegister(0x0b);
+    outb(CMOS_ADDRESS, 0x8b);
+    outb(CMOS_DATA, regB & 0xbf); // Clear bit 6
+    __asm__ volatile ("sti");
+}
+
+__attribute__ ((interrupt)) void rtcHandler(intFrame_t* iframe) {
+    datetime_t newDatetime, oldDatetime;
+    static uint16_t rtcTicks = 0;
+    
+    __asm__ volatile ("cli");
+    rtcTicks++;
+    if (rtcTicks % 1024 == 0) { // 1 Second has passed
+        while (cmosUpdateProgress()); // Wait
+        
+        newDatetime.second = getRtcRegister(0);
+        newDatetime.minute = getRtcRegister(2);
+        newDatetime.hour   = getRtcRegister(4);
+        newDatetime.day    = getRtcRegister(7);
+        newDatetime.month  = getRtcRegister(8);
+        newDatetime.year   = getRtcRegister(9);
+
+        do {
+            oldDatetime = newDatetime;
+
+            while (cmosUpdateProgress()); // Wait
+            newDatetime.second = getRtcRegister(0);
+            newDatetime.minute = getRtcRegister(2);
+            newDatetime.hour   = getRtcRegister(4);
+            newDatetime.day    = getRtcRegister(7);
+            newDatetime.month  = getRtcRegister(8);
+            newDatetime.year   = getRtcRegister(9);
+
+        } while (
+            newDatetime.second != oldDatetime.second ||
+            newDatetime.minute != oldDatetime.minute ||
+            newDatetime.hour   != oldDatetime.hour ||
+            newDatetime.day    != oldDatetime.day ||
+            newDatetime.month  != oldDatetime.month ||
+            newDatetime.year   != oldDatetime.year
+        );
+
+        uint8_t regB = getRtcRegister(0x0b);
+        if (!(regB & 0x04)) {
+            newDatetime.second = (newDatetime.second & 0x0f) + ((newDatetime.second >> 4) * 10);
+            newDatetime.minute = (newDatetime.minute & 0x0f) + ((newDatetime.minute >> 4) * 10);
+            newDatetime.hour   = ((newDatetime.hour  & 0x0f) + (((newDatetime.hour & 0x70) >> 4) * 10)) | (newDatetime.hour * 0x80); // 12/24 Hour format bs
+            newDatetime.day    = (newDatetime.day    & 0x0f) + ((newDatetime.day    >> 4) * 10);
+            newDatetime.month  = (newDatetime.month  & 0x0f) + ((newDatetime.month  >> 4) * 10);
+            newDatetime.year   = (newDatetime.year   & 0x0f) + ((newDatetime.year   >> 4) * 10);
+        }
+
+        // Convert 12 to 14 hour format
+        if (!(regB & 0x02) && (newDatetime.hour & 0x80)) {
+            newDatetime.hour = ((newDatetime.hour & 0x7f) + 12) % 24;
+        }
+
+        newDatetime.year += 2000; // Add current century
+        
+        //*datetime = newDatetime;
+
+        datetime->second = newDatetime.second;
+        datetime->minute = newDatetime.minute;
+        datetime->hour   = newDatetime.hour;
+        datetime->day    = newDatetime.day;
+        datetime->month  = newDatetime.month;
+        datetime->year   = newDatetime.year;
+
+        if (true) { // TODO: Probably get rid of this idk
+            char buf[20] = { 0 }; // "12/12 2012 12:12:12" - Max string 20 chars with null byte
+
+            strcat(buf, itoa(datetime->day, 10));
+            strcat(buf, "/");
+            strcat(buf, itoa(datetime->month, 10));
+            strcat(buf, " ");
+            strcat(buf, itoa(datetime->year, 10));
+            strcat(buf, " ");
+            strcat(buf, itoa(datetime->hour, 10));
+            strcat(buf, ":");
+            strcat(buf, itoa(datetime->minute, 10));
+            strcat(buf, ":");
+            strcat(buf, itoa(datetime->second, 10));
+
+            printAt("                    ", 30, 0);
+            bgColor = 0x0027323f;
+            fgColor = 0x00ededed;
+            printAt(buf, 30, 0);
+            bgColor = BG_COLOR;
+            fgColor = FG_COLOR;
+        }
+    }
+
+    getRtcRegister(0x0c);
+    sendPicEOI(8); 
+    
+    __asm__ volatile ("sti");
+}
+
+void setupRtc() { // IRQ 8 - Real Time Clock
+    idtSetGate(0x28, rtcHandler, INT_GATE_FLAGS);
+    unsetIrqMask(8);
+    enableRtc();
+}
+
+#endif