Merge pull request #40 from kushagra765/0.07

Added PIT Driver

Author: DamieFC

build.sh

@@ -22,13 +22,14 @@ nasm -f elf32 ./kernel/cpu/load_isr.asm -o load_isr.o
 i686-elf-gcc -I./kernel/include/ -I./kernel/drivers/ -c ./kernel/cpu/isr.c -o isr.o
 nasm -f elf32 ./kernel/cpu/load_irq.asm -o load_irq.o
 i686-elf-gcc -I./kernel/include/ -c ./kernel/cpu/irq.c -o irq.o
+i686-elf-gcc -I./kernel/ -I./kernel/include/ -c ./kernel/drivers/pit/pit.c -o pit.o
 i686-elf-gcc -I./kernel/drivers/ -c ./kernel/system/panic.c -o panic.o
 i686-elf-gcc -I./kernel/include/ -I./kernel/drivers/ -c ./kernel/system/memory.c -o memory.o
 i686-elf-gcc -I./kernel/drivers/ -I./kernel/system/ -I./kernel/include/ -c ./kernel/system/vtconsole.c -o vtconsole.o
 i686-elf-gcc -I./kernel/include/ -I./kernel/drivers/ -c ./kernel/fs/vfs/vfs.c -o vfs.o
 
 
-i686-elf-gcc -T ./kernel/arch/i386/linker.ld -o PlatypusOS.bin -ffreestanding -O2 -nostdlib boot.o vga.o keyboard.o ports.o gdt.o load_gdt.o idt.o load_idt.o isr.o load_isr.o irq.o load_irq.o panic.o memory.o vtconsole.o vfs.o main.o
+i686-elf-gcc -T ./kernel/arch/i386/linker.ld -o PlatypusOS.bin -ffreestanding -O2 -nostdlib boot.o vga.o keyboard.o ports.o gdt.o load_gdt.o idt.o load_idt.o isr.o load_isr.o irq.o load_irq.o pit.o panic.o memory.o vtconsole.o vfs.o main.o
 
 # After linking everything, remove the object files
 rm *.o

init/main.c

@@ -1,6 +1,7 @@
 #include <vga/vga.h>
 #include <keyboard/keyboard.h>
 #include <system/vtconsole.h>
+#include <pit/pit.h>
 #include <vfs.h>
 #include <gdt.h>
 #include <idt.h>
@@ -25,6 +26,8 @@ void kernel_main() {
      writestr("[OK] Load ISR\n");
      init_irq();
      writestr("[OK] Load IRQ\n");
+     writestr("[OK] Load PIT\n");
+     init_timer(50);
 
     /* Load Drivers */
      init_keyboard();
@@ -42,4 +45,4 @@ void kernel_main() {
     settextcolor(COLOR_WHITE, COLOR_BLACK);
     writestr("Hi! There's not much to do yet, but come back later for more stuff!\n");
     writestr("user@kernel: ");
-}
+}

kernel/drivers/pit/pit.c

@@ -0,0 +1,19 @@
+#include "pit.h"
+#include <cpu/irq.h>
+#include <kernel/ports.h>
+
+int kernel_timer_ticks = 0;
+
+void handler_timer() {
+  kernel_timer_ticks++;
+}
+
+void init_timer(int frequency) {
+
+  install_irq_handler(0, handler_timer);
+  int divisor = 1193180 / frequency;
+
+  outp(0x43, 0x36);
+  outp(0x40, frequency & 0xFF);
+  outp(0x40, frequency >> 8);
+}

kernel/drivers/pit/pit.h

@@ -0,0 +1,7 @@
+#ifndef _PIT_H
+#define _PIT_H
+
+void handler_timer();
+void init_timer(int frequency);
+
+#endif //_PIT_H