Added PIC code and init in kernel. Needs PIT to function.

src/asm.h

@@ -19,3 +19,13 @@ inline uint8_t inb(uint16_t port)
     asm volatile ("inb %1, %0" : "=a"(ret) : "Nd"(port));
     asm volatile ("inb %1, %0" : "=a"(ret) : "Nd"(port));
     return ret;
     return ret;
 }
 }
+
+inline void disable_int()
+{
+    asm volatile ("cli");
+}
+
+inline void enable_int()
+{
+    asm volatile ("sti");
+}

src/kern.c

@@ -15,7 +15,8 @@
 #include "idt.h"
 #include "idt.h"
 #include "test.h"
 #include "test.h"
 #include "multiboot.h"
 #include "multiboot.h"
-
+#include "pic.h"
+#include "pit.h"
 // The parameters passed here ultimately come through the bootloader
 // The parameters passed here ultimately come through the bootloader
 void kernel_main(multiboot_info* mbt, uint32_t magic)
 void kernel_main(multiboot_info* mbt, uint32_t magic)
 {
 {
@@ -24,12 +25,18 @@ void kernel_main(multiboot_info* mbt, uint32_t magic)
     serial_init();
     serial_init();
     gdt_init();
     gdt_init();
     idt_init(0x8);
     idt_init(0x8);
-
+    serial_writestring("IDT initialized\n");
+    disable_int();
+    pic_init(0x20,0x28);
+    pit_init();
+    pit_start_counter(100, PIT_OCW_CONT_0, PIT_OCW_MODE_SQWVGEN);
+    enable_int();
 	/* Since there is no support for newlines in terminal_putchar
 	/* Since there is no support for newlines in terminal_putchar
          * yet, '\n' will produce some VGA specific character instead.
          * yet, '\n' will produce some VGA specific character instead.
          * This is normal.
          * This is normal.
          */
          */
-    serial_writestring("IDT initialized\n");
+    
+    serial_writestring("Hello, kernel World!\n");
     terminal_writestring("Hello, kernel World!\n");
     terminal_writestring("Hello, kernel World!\n");
 
 
     // Abort if magic is not correct.
     // Abort if magic is not correct.

src/pic.c

+#include "pic.h"
+#include "asm.h"
+
+uint8_t pic_read(uint16_t pic)
+{
+    if(pic>1)
+    {
+	return;
+    }
+    uint16_t reg = (pic==0)? PIC1_REG_DATA:PIC2_REG_DATA;
+    return inb(reg);
+}
+
+void pic_write(uint16_t pic, uint8_t data)
+{
+    if(pic>1)
+    {
+	return;
+    }
+    uint16_t reg = (pic==0)? PIC1_REG_DATA:PIC2_REG_DATA;
+    outb(reg, data);
+}
+
+void pic_command(uint16_t pic, uint8_t cmd)
+{
+    if(pic>1)
+    {
+	return;
+    }
+    uint16_t reg = (pic==0)? PIC1_REG_COMD:PIC2_REG_COMD;
+    outb(reg, cmd);
+}
+
+//void pic_mask_irq(uint16_t pic, uint8_t irqmask)
+//{
+//    //TODO
+//}
+
+void pic_init(uint8_t base0, uint8_t base1)
+{
+    uint8_t icw=0;
+
+    //enab,e init and expect mode on both
+    icw = (icw & ~PIC_ICW1_INIT) | PIC_ICW1_INIT_YES;
+    icw = (icw & ~PIC_ICW1_IC4)  | PIC_ICW1_IC4_EXPECT;
+    pic_command(0, icw);
+    pic_command(1, icw);
+    
+    //send ICW2 (base irq address)
+    pic_write(0, base0);
+    pic_write(1, base1);
+
+    //now for magic flags to make the PICs connect
+    pic_write(0,0x04);
+    pic_write(1,0x02);
+
+    //enable x86 mode on PICs
+    icw = (icw & ~PIC_ICW4_UPM) | PIC_ICW4_UPM_86;
+    pic_write(0, icw);
+    pic_write(1, icw);
+}

src/pic.h

+#ifndef _PIC_INC
+#define _PIC_INC
+
+#include <stdint.h>
+
+//PIC 1
+#define PIC_IRQ_TIMER 0
+#define PIC_IRQ_KEYBD 1
+#define PIC_IRQ_SERL2 3
+#define PIC_IRQ_SERL1 4
+#define PIC_IRQ_PARL2 5
+#define PIC_IRQ_DISKT 6
+#define PIC_IRQ_PARL1 7
+//PIC 2
+#define PIC_IRQ_CMOST 0
+#define PIC_IRQ_CGART 1
+#define PIC_IRQ_AUXIL 4
+#define PIC_IRQ_FPU   5
+#define PIC_IRQ_HDC   6
+#endif
+
+//OCW2 masks
+#define	PIC_OCW2_L1   0x01	        
+#define	PIC_OCW2_L2   0x02
+#define	PIC_OCW2_L3   0x04		
+#define	PIC_OCW2_EOI  0x20
+#define	PIC_OCW2_SL   0x40
+#define	PIC_OCW2_ROT  0x80   
+//OCW3 masks
+#define	PIC_OCW3_RIS  0x01		
+#define	PIC_OCW3_RIR  0x02		
+#define	PIC_OCW3_MODE 0x04	
+#define	PIC_OCW3_SMM  0x20
+#define	PIC_OCW3_ESMM 0x40	
+#define	PIC_OCW3_D7   0x80
+
+//PIC1 reg ports
+#define PIC1_REG_COMD 0x20
+#define PIC1_REG_STAT 0x20
+#define PIC1_REG_DATA 0x21
+#define PIC1_REG_IMR  0x21
+//PIC2 reg ports
+#define PIC2_REG_COMD 0xA0
+#define PIC2_REG_STAT 0xA0
+#define PIC2_REG_DATA 0xA1
+#define PIC2_REG_IMR  0xA1
+
+//ICW1 masks
+#define PIC_ICW1_IC4  0x01
+#define PIC_ICW1_SNGL 0x02
+#define PIC_ICW1_ADI  0x04
+#define PIC_ICW1_LRIM 0x08
+#define PIC_ICW1_INIT 0x10
+//ICW4 masks
+#define PIC_ICW4_UPM  0x01
+#define PIC_ICW4_AEOI 0x02
+#define PIC_ICW4_MS   0x04
+#define PIC_ICW4_BUF  0x08
+#define PIC_ICW4_SFNM 0x10
+
+//ICW1 control bits
+#define PIC_ICW1_IC4_EXPECT 0x01
+#define PIC_ICW1_IC4_NO	    0x00
+#define PIC_ICW1_SNGL_YES   0x02
+#define PIC_ICW1_SNGL_NO    0x00
+#define PIC_ICW1_ADI_INTVL4 0x04
+#define PIC_ICW1_ADI_INTVL8 0x00	
+#define PIC_ICW1_LTIM_LEVEL 0x08	
+#define PIC_ICW1_LTIM_EDGE  0x00	
+#define PIC_ICW1_INIT_YES   0x10
+#define PIC_ICW1_INIT_NO    0x00
+//ICW4 control bits
+#define PIC_ICW4_UPM_86	    0x01
+#define PIC_ICW4_UPM_MCS    0x00
+#define PIC_ICW4_AEOI_AUTO  0x02
+#define PIC_ICW4_AEOI_NO    0x00
+#define PIC_ICW4_MS_MASTER  0x04
+#define PIC_ICW4_MS_SLAVE   0x00
+#define PIC_ICW4_BUF_YES    0x08
+#define PIC_ICW4_BUF_NO	    0x00
+#define PIC_ICW4_SFNM_NEST  0x10
+#define PIC_ICW4_SFNM_NOT   0x00
+
+
+uint8_t pic_read(uint16_t pic);
+void pic_write(uint16_t pic, uint8_t data);
+void pic_command(uint16_t pic, uint8_t cmd);
+void pic_mask_irq(uint16_t pic, uint8_t irqmask);
+void pic_init(uint8_t base0, uint8_t base1);