Added code to support getting interrupts from the PIC. Can now get some data from the keyboard, however, it's not quite working yet.

build_numbers.c

@@ -1,3 +1,3 @@
 #ifndef KERNEL_VERSION_NUMBER
-#define KERNEL_VERSION_NUMBER "0.0.3-2"
+#define KERNEL_VERSION_NUMBER "0.0.3-46"
 #endif

includes/idt.h

@@ -16,6 +16,6 @@ struct idt_ptr
 } __attribute__((packed));
 
 void install_idt(void);
-void idt_set_gate(struct idt_entry*, unsigned long, unsigned short, unsigned char);
+void idt_set_gate(unsigned char, unsigned long, unsigned short, unsigned char);
 void load_idt(struct idt_ptr*);
 #endif

includes/irq.h

@@ -0,0 +1,21 @@
+#ifndef IRQ_H
+#define IRQ_H
+
+extern void irq0();
+extern void irq1();
+extern void irq2();
+extern void irq3();
+extern void irq4();
+extern void irq5();
+extern void irq6();
+extern void irq7();
+extern void irq8();
+extern void irq9();
+extern void irq10();
+extern void irq11();
+extern void irq12();
+extern void irq13();
+extern void irq14();
+extern void irq15();
+
+#endif

includes/kb.h

@@ -0,0 +1,7 @@
+#ifndef KB_H
+#define KB_H
+
+void handle_key_press(void);
+void init_kb(void);
+
+#endif

includes/kernel.h

@@ -1,4 +1,5 @@
 #ifndef KERNEL_H
 #define KERNEL_H
 void kmain();
+void kb_c();
 #endif

includes/pic.h

@@ -0,0 +1,7 @@
+#ifndef PIC_H
+#define PIC_H
+
+void pic_acknowledge(unsigned int);
+void setup_pics(void);
+
+#endif

includes/screen.h

@@ -4,4 +4,5 @@ void draw_string(char*, unsigned char, unsigned char);
 int strlen(char*);
 void clear_screen(void);
 void print_banner(void);
+char* int_to_string(unsigned int, int);
 #endif

kernel/idt.c

@@ -18,44 +18,45 @@ void idt_install()
     // For the kernel ring 8E is chosen
     // 100 for bits 7-5. 1 (present) 00 (the level in this case ring zero)
     // 01110 for bits 4-0. This is always set to 14.
-    idt_set_gate(&idt_entries[0], (unsigned int) isr0, 0x08, 0x8E);
+    idt_set_gate(0, (unsigned int) isr0, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[1], (unsigned int) isr1, 0x08, 0x8E);
+    idt_set_gate(1, (unsigned int) isr1, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[2], (unsigned int) isr2, 0x08, 0x8E);
+    idt_set_gate(2, (unsigned int) isr2, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[3], (unsigned int) isr3, 0x08, 0x8E);
+    idt_set_gate(3, (unsigned int) isr3, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[4], (unsigned int) isr4, 0x08, 0x8E);
+    idt_set_gate(4, (unsigned int) isr4, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[5], (unsigned int) isr5, 0x08, 0x8E);
+    idt_set_gate(5, (unsigned int) isr5, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[6], (unsigned int) isr6, 0x08, 0x8E);
+    idt_set_gate(6, (unsigned int) isr6, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[7], (unsigned int) isr7, 0x08, 0x8E);
+    idt_set_gate(7, (unsigned int) isr7, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[8], (unsigned int) isr8, 0x08, 0x8E);
+    idt_set_gate(8, (unsigned int) isr8, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[9], (unsigned int) isr9, 0x08, 0x8E);
+    idt_set_gate(9, (unsigned int) isr9, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[10], (unsigned int) isr10, 0x08, 0x8E);
+    idt_set_gate(10, (unsigned int) isr10, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[11], (unsigned int) isr11, 0x08, 0x8E);
+    idt_set_gate(11, (unsigned int) isr11, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[12], (unsigned int) isr12, 0x08, 0x8E);
+    idt_set_gate(12, (unsigned int) isr12, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[13], (unsigned int) isr13, 0x08, 0x8E);
+    idt_set_gate(13, (unsigned int) isr13, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[14], (unsigned int) isr14, 0x08, 0x8E);
+    idt_set_gate(14, (unsigned int) isr14, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[15], (unsigned int) isr15, 0x08, 0x8E);
+    idt_set_gate(15, (unsigned int) isr15, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[16], (unsigned int) isr16, 0x08, 0x8E);
+    idt_set_gate(16, (unsigned int) isr16, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[17], (unsigned int) isr17, 0x08, 0x8E);
+    idt_set_gate(17, (unsigned int) isr17, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[18], (unsigned int) isr18, 0x08, 0x8E);
+    idt_set_gate(18, (unsigned int) isr18, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[19], (unsigned int) isr19, 0x08, 0x8E);
+    idt_set_gate(19, (unsigned int) isr19, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[20], (unsigned int) isr20, 0x08, 0x8E);
+    idt_set_gate(20, (unsigned int) isr20, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[21], (unsigned int) isr21, 0x08, 0x8E);
+    idt_set_gate(21, (unsigned int) isr21, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[22], (unsigned int) isr22, 0x08, 0x8E);
+    idt_set_gate(22, (unsigned int) isr22, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[23], (unsigned int) isr23, 0x08, 0x8E);
+    idt_set_gate(23, (unsigned int) isr23, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[24], (unsigned int) isr24, 0x08, 0x8E);
+    idt_set_gate(24, (unsigned int) isr24, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[25], (unsigned int) isr25, 0x08, 0x8E);
+    idt_set_gate(25, (unsigned int) isr25, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[26], (unsigned int) isr26, 0x08, 0x8E);
+    idt_set_gate(26, (unsigned int) isr26, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[27], (unsigned int) isr27, 0x08, 0x8E);
+    idt_set_gate(27, (unsigned int) isr27, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[28], (unsigned int) isr28, 0x08, 0x8E);
+    idt_set_gate(28, (unsigned int) isr28, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[29], (unsigned int) isr29, 0x08, 0x8E);
+    idt_set_gate(29, (unsigned int) isr29, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[30], (unsigned int) isr30, 0x08, 0x8E);
+    idt_set_gate(30, (unsigned int) isr30, 0x08, 0x8E);
-    idt_set_gate(&idt_entries[31], (unsigned int) isr31, 0x08, 0x8E);
+    idt_set_gate(31, (unsigned int) isr31, 0x08, 0x8E);
     
     load_idt(&idt);
 }
 
-void idt_set_gate(struct idt_entry* entry, unsigned long base, unsigned short sel, unsigned char flags)
+void idt_set_gate(unsigned char index, unsigned long base, unsigned short sel, unsigned char flags)
 {
+	struct idt_entry* entry = &idt.idt_entries_start[index];
 	entry->base_lo = (base & 0xFFFF);
 	entry->base_hi = (base >> 16) & 0xFFFF;
 	

kernel/interrupt_handler.c

@@ -1,8 +1,10 @@
 #include "../includes/interrupt_handler.h"
 #include "../includes/serial.h"
+#include "../includes/screen.h"
 
 void interrupt_handler(struct isr_state stack)
 {
+	write_to_com(COM1_PORT, int_to_string(stack.int_no, 10));
 	write_to_com(COM1_PORT, "Divide by zero detected!\n");
 	write_to_com(COM1_PORT, "Halting system!\n");
 	asm("cli");

kernel/interrupt_service_routines.s

@@ -29,7 +29,7 @@ global isr27
 global isr28
 global isr29
 global isr30
-global isr31	; reserved
+global isr31	; Reserved
 
 isr0:			; division by zero
 	cli

kernel/irq.s

@@ -0,0 +1,67 @@
+global irq0		; PIC Timer Interrupt
+global irq1		; Keyboard
+global irq2		; Cascade (Used internally by the two PICs; never raised)
+global irq3		; COM2
+global irq4		; COM1
+global irq5		; LPT2
+global irq6		; Floppy Disk
+global irq7		; LPT1
+global irq8		; CMOS realt-time clock
+global irq9		; Free for perpherals / legacy SCSI / NIC
+global irq10	; Free for perpherals / NIC
+global irq11	; Free for perpherals / NIC
+global irq12	; PS2 mouse
+global irq13	; FPU / Coprocessor / Inter-process
+global irq14	; Primary ATA HDD
+global irq15	; Secondary ATA HDD
+
+extern handle_key_press
+
+irq0:
+	iret
+
+irq1:
+	call handle_key_press
+	iret
+	
+irq2:
+	iret
+	
+irq3:
+	iret
+	
+irq4:
+	iret
+	
+irq5:
+	iret
+	
+irq6:
+	iret
+	
+irq7:
+	iret
+	
+irq8:
+	iret
+	
+irq9:
+	iret
+	
+irq10:
+	iret
+	
+irq11:
+	iret
+	
+irq12:
+	iret
+	
+irq13:
+	iret
+	
+irq14:
+	iret
+	
+irq15:
+	iret

kernel/kb.c

@@ -0,0 +1,27 @@
+#include "../includes/kb.h"
+#include "../includes/pic.h"
+#include "../includes/screen.h"
+
+#define KB_PORT 0x60
+#define KB_STATUS_PORT 0x64
+
+void handle_key_press()
+{
+	pic_acknowledge(33);
+	
+	unsigned char status = inb(KB_STATUS_PORT);
+	
+	if(status & 0x01)
+	{
+		char keycode = inb(KB_PORT);
+	
+		if(keycode < 0) return;
+		
+		draw_string(int_to_string(keycode, 10), 0xF, 0x0);
+	}
+}
+
+void init_kb()
+{
+	outb(0x21, 0xFD);
+}

kernel/kmain.c

@@ -4,6 +4,8 @@
 #include "../includes/serial.h"
 #include "../includes/screen.h"
 #include "../includes/loader.h"
+#include "../includes/pic.h"
+#include "../includes/kb.h"
 
 struct multiboot_header header  __attribute((section(".multiboot"))) = (struct multiboot_header) {.magic = 0x1BADB002, .flags = 0x1, .checksum = -464367619};
 
@@ -26,9 +28,14 @@ void kmain()
 	print_message("Installing IDT...\n", 0xF, 0x0);
 	idt_install();
 	print_message("IDT installed.\n", 0xF, 0x0);
-	
+	//asm("xchg %bx, %bx"); // Boch's break point
-	int i = 5 / 0;
+	setup_pics();
-	asm("hlt");
+	//kb
+	init_kb();
+	//asm("xchg %bx, %bx");
+	asm("sti");
+	//for(;;);
+	idle();
 }
 
 void print_message(unsigned char* msg, unsigned char fg, unsigned char bg)
@@ -36,3 +43,8 @@ void print_message(unsigned char* msg, unsigned char fg, unsigned char bg)
 	write_to_com(COM1_PORT, msg);
 	draw_string(msg, fg, bg);
 }
+
+void idle()
+{
+	for(;;) asm("hlt");
+}

kernel/pic.c

@@ -0,0 +1,58 @@
+#include "../includes/pic.h"
+#include "../includes/io.h"
+#include "../includes/idt.h"
+#include "../includes/irq.h"
+
+#define PIC1_PORT 				0x20
+#define PIC1_DATA_PORT			0X21
+#define PIC2_PORT 				0xA0
+#define PIC2_DATA_PORT			0XA1
+
+#define PIC1_START_INTERRUPT 	0x20
+#define PIC2_START_INTERRUPT 	0x28
+#define PIC2_END_INTERRUPT   	PIC2_START_INTERRUPT + 7
+
+#define PIC_ACK 				0x20
+
+void pic_acknowledge(unsigned int interrupt_no)
+{
+	if (interrupt_no < PIC2_START_INTERRUPT)
+		outb(PIC1_PORT, PIC_ACK);
+	else
+		outb(PIC2_PORT, PIC_ACK);
+}
+
+void setup_pics(void)
+{
+	// The PIC uses Initialization Command Words (ICW) to communicate.
+	// So we start with the first ICW, 0x11, this tells the PIC to expect 
+	// 3 more ICWs.
+	outb(PIC1_PORT, 0x11);
+	outb(PIC2_PORT, 0x11);
+	
+	// This tells the pic what offset to use when it generates the interrupt numbers.
+	// Since the first 32 ISRs are reserved by the CPU we must start at IRS32 and work
+	// our way up. When the PIC recieves an interrupt on it's input line, it will add
+	// the supplied values to that number before sending the newly made number to the CPU.
+	// Thereby remapping an interrupt number that would have normally conflicted with the 
+	// values in the IDT.
+	outb(PIC1_DATA_PORT, PIC1_START_INTERRUPT);
+	outb(PIC2_DATA_PORT, PIC2_START_INTERRUPT);
+	
+	// This ICW allows for cascading of their outputs to inputs between each other.
+	// I'm not sure what that really means but at this current time I'm not going to
+	// be doing this, so the bits will all be set to zero.
+	outb(PIC1_DATA_PORT, 0x00);
+	outb(PIC2_DATA_PORT, 0x00);
+	
+	// This is the environment info, and setting the lowest bit tells the PICs
+	// that we're running in 80x86 mode.
+	outb(PIC1_DATA_PORT, 0x01);
+	outb(PIC2_DATA_PORT, 0x01);
+	
+	// Finally, we have the interrupt masks.
+	outb(PIC1_DATA_PORT, 0xFF);
+	outb(PIC2_DATA_PORT, 0xFF);
+	
+	idt_set_gate(33, (unsigned long) &irq1, 0x08, 0x8E);
+}

kernel/screen.c

@@ -119,3 +119,38 @@ int strlen(char* string)
 	
 	return len;
 }
+
+//Code reference:
+//http://www.strudel.org.uk/itoa/
+char* int_to_string(unsigned int value, int base)
+{
+	static char buf[32] = {0};
+	//void* ptr = Malloc(32);
+	//if(ptr == 0)
+	//{
+		//puts("Malloc failed to allocate!\n");
+		//return "";
+	//}
+	
+	//char buf = (char*) ptr;
+	
+	if(value == 0)
+	{
+		buf[0] = '0';
+		//*buf++ = '0';
+		//return buf;
+		return &buf[0];
+	}
+
+	int i = 30;
+
+	for(; value && i; --i, value /= base)
+	{
+		//*buf++ = "0123456789ABCDEF"[value % base];
+		buf[i] = "0123456789ABCDEF"[value % base];
+	}
+	
+	//Free(ptr);
+	//return buf;
+	return &buf[i+1];
+}