time

.env

@@ -3,7 +3,7 @@ LD=i386-elf-ld
 AS=nasm
 AR=ar
 
-CFLAGS=-ffreestanding -m32 -O2 -Wall -Wextra -pedantic -DKERNEL_LOG
+CFLAGS=-ffreestanding -m32 -O2 -Wall -Wextra -pedantic # -DKERNEL_LOG
 LDFLAGS=-nostdlib
 
 QEMU=qemu-system-i386

.gitignore

@@ -1,4 +1,4 @@
-/boot
+/iso
 /os.iso
 /kernel/bin
 /libk/bin

Makefile

@@ -1,6 +1,6 @@
 include .env
 
-.PHONY: all libk kernel
+.PHONY: all libk kernel clean run
 
 all: os.iso
 
@@ -11,16 +11,16 @@ kernel:
 	make --directory=kernel
 
 os.iso: libk kernel
-	rm -fr os.iso
+	@rm -fr os.iso
-	mkdir -p boot/grub
+	@mkdir -p iso/boot/grub
-	cp grub.cfg boot/grub
+	cp grub.cfg iso/boot/grub
-	cp kernel/bin/kernel.bin boot
+	cp kernel/bin/kernel.bin iso/boot
-	grub-mkrescue -o os.iso .
+	grub-mkrescue -o os.iso iso
 
 clean:
 	make --directory=libk clean
 	make --directory=kernel clean
-	rm -fr boot
+	rm -fr iso
 	rm -fr os.iso
 
 run:

kernel/Makefile

@@ -4,7 +4,7 @@ C_SRC = $(shell find src -type f -name "*.c")
 C_OBJ = $(patsubst %.c,bin/%.o, $(C_SRC))
 
 ASM_SRC = $(shell find src -type f -name "*.asm")
-ASM_OBJ = $(patsubst %.asm,bin/%.o, $(ASM_SRC))
+ASM_OBJ = $(patsubst %.asm,bin/%.asm.o, $(ASM_SRC))
 
 CFLAGS += -Iinclude -Isrc -I../libk/include -std=gnu17
 
@@ -16,7 +16,7 @@ $(C_OBJ): bin/%.o : %.c
 	@mkdir -p $(@D)
 	$(CC) -c $(CFLAGS) -o $@ $<
 
-$(ASM_OBJ): bin/%.o : %.asm
+$(ASM_OBJ): bin/%.asm.o : %.asm
 	@mkdir -p $(@D)
 	$(AS) $< -f elf -o $@
 

kernel/include/time.h

@@ -0,0 +1,30 @@
+#pragma once 
+
+#include <stddef.h>
+
+struct Time {
+    int sec;    /// Seconds [0,59]
+    int min;    /// Minutes [0,59]
+    int hour;   /// Hour [0,23]
+    int mday;   /// Day of month [1,31]
+    int mon;    /// Month of year [0,11]
+    int year;   /// Years since 1900
+    int wday;   /// Day of week [0,6] (Sunday = 0)
+    int yday;   /// Day of year [0,365]
+    int yn;     /// Year number [0,99]
+    int cen;    /// Century [19,20]
+    int leap;   /// If year is a leap year (True == 1)
+};
+
+extern void rtc_update(void);
+extern void rtc_set_timezone(int offset);
+extern struct Time *rtc_utctime(void);
+extern struct Time *rtc_localtime(void);
+
+/**
+ * Converts the time into a string format
+ * @param time the current time
+ * @param format see manpage for date
+ * @param buf the buffer to store it in
+ */
+extern void timetostr(struct Time *time, char *format, char *buf, size_t n);

kernel/src/boot/tag.c

@@ -4,7 +4,6 @@
 #include "print.h"
 #include "tag.h"
 #include "acpi/acpi.h"
-#include "graphics/framebuffer.h"
 #include "memory/memory.h"
 
 static struct BootInfo info;
@@ -18,12 +17,6 @@ static void read_cmdline(struct BootTag *tag, char *data, uint8_t len) {
     info.tags[ID_CMDLINE] = *tag;
 }
 
-static void read_framebuffer(struct BootTag *tag, uint32_t *data) {
-    debugk("Found framebuffer");
-    tag->data.framebuffer = (struct Framebuffer *) data;
-    info.tags[ID_FRAMEBUFFER] = *tag;;
-}
-
 static void read_memorymap(struct BootTag *tag, uint32_t *data) {
     debugk("Found memorymap");
     tag->data.memory_map = (struct MemoryMap *) data;
@@ -48,9 +41,6 @@ static uint32_t *read_tag(uint32_t *data) {
         case ID_CMDLINE:
             read_cmdline(&tag, (char *)(data + 2), data_len);
             break;
-        case ID_FRAMEBUFFER:
-            read_framebuffer(&tag, data + 2);
-            break;
         case iD_MEMORYMAP:
             read_memorymap(&tag, data + 2);
             break;

kernel/src/boot/tag.h

@@ -4,7 +4,6 @@
 #include <stdint.h>
 
 #include "acpi/acpi.h"
-#include "graphics/framebuffer.h"
 #include "memory/memory.h"
 
 #define CMDLINE_MAX 32
@@ -15,7 +14,6 @@ struct BootTag {
     uint32_t size;
     union {
         char cmdline[CMDLINE_MAX];
-        struct Framebuffer *framebuffer;
         struct MemoryMap *memory_map;
         struct RootSystemDescriptionPointer *rsdp;
     } data;
@@ -30,7 +28,6 @@ struct BootInfo {
 enum BootTagID {
     ID_CMDLINE = 0,
     iD_MEMORYMAP = 6,
-    ID_FRAMEBUFFER = 8,
     ID_RSDP = 14
 };
 

kernel/src/cpu/fpu.asm

@@ -9,7 +9,7 @@ fpu_init:
     cmp word [test], 0                 
     jne no_fpu
     
-    xor eax, 0
+    mov eax, 0
     ret
 
 no_fpu:

kernel/src/drivers/cmos.c

@@ -0,0 +1,138 @@
+#include "print.h"
+#include <stdint.h>
+#include <sys.h>
+#include <time.h>
+
+#define CMOS_WRITE_PORT 0x70
+#define CMOS_READ_PORT  0x71
+
+#define CMOS_REG_SEC    0x00
+#define CMOS_REG_MIN    0x02
+#define CMOS_REG_HOUR   0x04
+#define CMOS_REG_WDAY   0x06
+#define CMOS_REG_MDAY   0x07
+#define CMOS_REG_MON    0x08
+#define CMOS_REG_YEAR   0x09
+#define CMOS_REG_CEN    0x32
+
+static struct Time time;
+static struct Time localtime;
+static int cur_offset = 0;
+
+static uint8_t cmos_read(uint8_t reg) {
+    uint8_t hex, ret;
+    
+    outb(CMOS_WRITE_PORT, reg);
+    hex = inb(CMOS_READ_PORT);
+
+    ret = hex & 0x0F;
+    ret += (hex & 0xF0) / 16 * 10;
+
+    return ret;
+}
+
+static int mday_offset[12] = {
+    0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
+};
+
+static int month_days[12] = {
+    31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+static void update_localtime(void) {
+
+    int change, max;
+
+    // set localtime
+    localtime = time;
+
+    // do we acutally need to do anything
+    if (cur_offset == 0) return;
+    localtime.hour += cur_offset;
+    
+    // check if day rolled over
+    change = localtime.hour < 0 ? -1 : localtime.hour >= 24 ? 1 : 0;
+    if (!change) return;
+
+    // roll over day
+    localtime.hour = (localtime.hour + 24) % 24;
+    localtime.wday = (localtime.wday + change + 7) % 7;
+    localtime.mday += change;
+    localtime.yday += change;
+    
+    // check if month rolled over
+    max = month_days[localtime.mon];
+    if (localtime.leap && localtime.mon == 1) max++;
+    change = localtime.mday < 0 ? -1 : localtime.mday >= max ? 1 : 0;
+    if (!change) return;
+
+    // roll over month
+    localtime.mon = (localtime.mon + change + 12) % 12;
+    
+    // check if year rolled over
+    max = localtime.leap ? 366 : 365;
+    change = localtime.yday < 0 ? -1 : localtime.yday >= max ? 1 : 0;
+    if (!change) return;
+
+    // roll over year
+    localtime.yn += change;
+
+    // check if cen rolled over
+    change = localtime.yn < 0 ? -1 : localtime.yn >= 100 ? 1 : 0;
+    if (!change) goto year;
+
+    // roll over cen
+    localtime.cen += change;
+
+
+year:
+
+    localtime.year = localtime.yn + localtime.cen * 100;
+    localtime.leap = localtime.year % 4 == 0 && localtime.year % 100 != 0;
+
+    if (localtime.leap && localtime.yday == -1)
+        localtime.yday = 365;
+    else if (localtime.yday == -1)
+        localtime.yday = 364;
+    else
+        localtime.yday = 0;
+
+    localtime.year -= 1900;
+
+}
+
+void rtc_set_timezone(int offset) {
+    cur_offset = offset;
+}
+
+void rtc_update(void) {
+    time.sec = cmos_read(CMOS_REG_SEC);
+    time.min = cmos_read(CMOS_REG_MIN);
+    time.hour = cmos_read(CMOS_REG_HOUR);
+    time.wday = cmos_read(CMOS_REG_WDAY) - 1;
+    time.mday = cmos_read(CMOS_REG_MDAY);
+    time.mon = cmos_read(CMOS_REG_MON) - 1;
+    time.yn = cmos_read(CMOS_REG_YEAR);
+    time.cen = 20;
+
+    time.year = time.yn + time.cen * 100;
+
+    time.leap = time.year % 4 == 0 && time.year % 100 != 0;
+
+    time.yday = mday_offset[time.mon] + time.mday;
+
+    if (time.leap && time.mon > 2)
+        time.yday++;
+    
+    time.year -= 1900;
+
+    update_localtime();
+}
+
+struct Time *rtc_utctime(void) {
+    return &time;
+}
+
+struct Time *rtc_localtime(void) {
+     return &localtime;
+}

kernel/src/graphics/framebuffer.h

@@ -1,15 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-
-struct Framebuffer {
-    uint64_t addr;
-    uint32_t pitch;
-    uint32_t width;
-    uint32_t height;
-    uint8_t depth;
-    uint8_t type;
-    uint8_t reserved;
-    // struct FramebufferPallete palettes[];
-
-} __attribute__ ((packed));

kernel/src/interrupt/idt.c

@@ -9,25 +9,35 @@
 #include "acpi/acpi.h"
 #include "drivers/ps2kb.h"
 #include "drivers/ps2mouse.h"
+#include "time.h"
 #include "tty/color.h"
 #include "idt.h"
 #include "pic.h"
 #include "tty/term.h"
 
-static int timer = 0;
+#define WIDTH 30
+static char buf[WIDTH];
+static int timer = -1;
 
 void idt_pic_eoi(uint8_t exception) {
 	pic_eoi(exception - PIC_REMAP_OFFSET);
 }
 
 void idt_pic_timer(void) {
-	uint32_t state = term_save();
+
-	term_setfg(VGA_LIGHT_GREEN);
-	term_setpos(60, 0);
-	puts("        ");
-	term_setpos(60, 0);
-	printk("%d", timer);
 	timer += 1;
+    if (timer % 20 != 0) return;
+
+    uint32_t state = term_save();
+
+    term_setfg(VGA_LIGHT_GREEN);
+	term_setpos(TERM_W - WIDTH - 1, 0);
+    for (size_t i = 0; i < WIDTH; i++) putchar(' ');
+	term_setpos(TERM_W - WIDTH - 1, 0);
+    
+    timetostr(rtc_localtime(), "%a %b %d %Y %H:%M:%S", buf, WIDTH);
+    printk("%s", buf);
+
 	term_load(state);
 }
 

kernel/src/main.c

@@ -6,6 +6,7 @@
 #include "drivers/ps2mouse.h"
 #include "interrupt/idt.h"
 #include "interrupt/pic.h"
+#include "time.h"
 #include "tty/cursor.h"
 #include "tty/term.h"
 
@@ -21,6 +22,9 @@ void kernel_main(void* boot_info) {
     term_init();
     cursor_enable();
 
+    rtc_set_timezone(-4);
+    rtc_update();
+
     idt_init();
     pic_remap(PIC_REMAP_OFFSET);
 
@@ -64,5 +68,8 @@ void kernel_main(void* boot_info) {
             y = fclamp(y, 0, TERM_H);
             printk(" x%d y%d\n", (int)x, (int)y);
         }
-    }
+
+        term_flush();
+        rtc_update();
+    } 
 }

kernel/src/print/time.c

@@ -0,0 +1,146 @@
+#include <stdbool.h>
+#include <string.h>
+#include <time.h>
+#include <stddef.h>
+
+static char* ABB_WEEKDAY[7] = {
+    "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+};
+
+static char* FULL_WEEKDAY[7] = {
+    "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturady"
+};
+
+static char* ABB_MONTH[12] = {
+    "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+};
+
+static char* FULL_MONTH[12] = {
+    "January", "Feburary", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
+};
+
+static char *write_num(unsigned int num, unsigned int pad, char *buf, size_t n) {
+    size_t digits = 1;
+    unsigned int x = num;
+
+    while (x /= 10, x > 0) digits++;
+    if (pad == 0) pad = digits;
+
+    for (size_t i = 0; i < pad; i++) {
+
+        size_t digit;
+        if (i >= digits) {
+            digit = 0;
+        } else {
+            digit = num % 10;
+            num /= 10;
+        }
+
+        if (pad - i - 1 >= n) continue;
+        buf[pad - i - 1] = '0' + digit;
+        
+    }
+
+    if (pad > n) pad = n;
+
+    return buf + pad;
+}
+
+void timetostr(struct Time *time, char *format, char *buf, size_t n) {
+    char *index = buf;
+    char c;
+    int space;
+
+    while (
+        c = *format++, 
+        space = (buf + n) - index,
+        c != '\0' && space > 0
+    ) {
+        if (c != '%') {
+            *index++ = c;
+            continue;
+        } else {
+            c = *format++;
+        }
+
+        switch (c) {
+            case '%':
+                *index++ = '%';
+                break;
+            case 'a':
+                index = strncpy(index, ABB_WEEKDAY[time->wday], space);
+                break;
+            case 'A':
+                index = strncpy(index, FULL_WEEKDAY[time->wday], space);
+                break;
+            case 'b':
+            case 'h':
+                index = strncpy(index, ABB_MONTH[time->mon], space);
+                break;
+            case 'B':
+                index = strncpy(index, FULL_MONTH[time->mon], space);
+                break;
+            case 'C':
+                index = write_num(time->cen, 0, index, space);
+                break;
+            case 'd':
+                index = write_num(time->mday, 2, index, space);
+                break;
+            case 'H':
+                index = write_num(time->hour, 2, index, space);
+                break;
+            case 'I':
+                index = write_num((time->hour + 12) % 12 + 1, 2, index, space);
+                break;
+            case 'j':
+                index = write_num(time->yday, 3, index, space);
+                break;
+            case 'm':
+                index = write_num(time->mon + 1, 2, index, space);
+                break;
+            case 'M':
+                index = write_num(time->min, 2, index, space);
+                break;
+            case 'n':
+                *index++ = '\n';
+                break;
+            case 'p':
+                index = strncpy(index, time->hour > 11 ? "PM" : "AM", space);
+                break;
+            case 'P':
+                index = strncpy(index, time->hour > 11 ? "pm" : "am", space);
+                break;
+            case 'q':
+                index = write_num((time->mon + 3) / 3, 0, index, space);
+                break;
+            case 'S':
+                index = write_num(time->sec, 2, index, space);
+                break;
+            case 't':
+                *index++ = '\t';
+                break;
+            case 'u':
+                index = write_num(((time->wday + 1 )% 7) + 1, 0, index, space);
+                break;
+            case 'w':
+                index = write_num(time->wday, 0, index, space);
+                break;
+            case 'y':
+                index = write_num(time->yn, 2, index, space);
+                break;
+            case 'Y':
+                index = write_num(time->year + 1900, 0, index, space);
+                break;
+            default: {
+                char b[3] = {'%', c, '\0'};
+                index = strncpy(index, b, space);
+                break;
+            }
+        }
+    }
+
+    if (space < 1)
+        buf[n - 1] = '\0';
+    else 
+        *index = '\0';
+}

kernel/src/tty/term.c

@@ -9,7 +9,8 @@
 #include "color.h"
 #include "cursor.h"
 
-uint16_t *buffer;
+uint16_t buffer[TERM_W * TERM_H * sizeof(uint16_t)];
+uint16_t *front;
 uint8_t x, y;
 uint8_t color;
 
@@ -27,7 +28,7 @@ static void term_clear_line(int y) {
 void term_init (void) {
     x = 0;
     y = 0;
-    buffer = (uint16_t*) 0xb8000;
+    front = (uint16_t*) 0xb8000;
     term_setfg(VGA_WHITE);
     term_setbg(VGA_BLACK);
     term_clear();
@@ -129,3 +130,9 @@ void putchar(int c) {
 bool term_newline(void) {
     return x == 0;
 }
+
+void term_flush(void) {
+    int_disable();
+    memcpy(front, buffer, TERM_W * TERM_H * sizeof(uint16_t));
+    int_enable();
+}

kernel/src/tty/term.h

@@ -25,3 +25,5 @@ uint16_t term_save_col(void);
 void term_load_col(uint16_t color);
 
 bool term_newline(void);
+
+void term_flush(void);