//kernel.c
//08/13/03 Josh Holtrop
//Holtrop's Operating System
//Version: 0.12
//Modified: 11/12/03

#include "k_defines.h"		//#DEFINE's for kernel


#include "functions.h"		//general functions
#include "video.h"		//video functions
#include "mm.h"			//physical memory management functions
#include "vmm.h"		//virtual memory management & paging functions
#include "keyboard.h"		//generic keyboard driver & functions
#include "mouse.h"		//generic ps/2 mouse driver & functions
#include "fdc.h"		//Floppy Disk Controller functions
#include "stdfont.h"		//Standard font bitmask array
#include "kio.h"

void isr(dword num);
void k_init();

/* These functions are defined in asmfuncs.asm */
extern dword write_cr0(dword cr0);
extern dword read_cr0();
extern dword write_cr3(dword cr3);
extern dword read_cr3();
extern void writeCursorPosition(dword pos);
extern dword getCursorPosition();
extern void console_scroll();
extern void console_cls();
extern int puts(char *str);
extern int putDec(int number);
extern int putDecu(dword number);

#include "kio.c"
#include "fdc.c"
#include "mouse.c"
#include "keyboard.c"
#include "mm.c"
#include "vmm.c"
#include "functions.c"
#include "video.c"

dword	timer = 0;

//Main kernel initialization method
void k_init()
{
		// ===== Initialization
	fdc_sendDOR(0x0C);		//turn off floppy motor!!
	console_cls();
	video_init();
	mm_init();
	vmm_init();
	remap_pics(0x20, 0x28);
	init_timer();
	mouse_init();
	pic1_mask(0);			//unmask IRQ's 0-7
	pic2_mask(0);			//unmask IRQ's 8-15
	enable_ints();
	kbd_resetLEDs();		//after enabling interrupts!!

	printf("HOS 0.12 - Kernel Size: %u kb\n", kernel_size()/1024);
	printf("Memory available to OS: %u MB (Bytes: %u)\n", mm_megabytes, mm_totalmem);
	printf("Free memory: %u bytes\t %u pages\n", mm_freemem(), mm_freemem()>>12);
	
	if (videoMode)
	{
		dword p;
		for (p = 0; p < video_mode.XResolution*video_mode.YResolution; p++)
			video_psetp(p, 0x00000055);
	}

	dword callnum = 0;
	dword fa = 0;
	dword la;
	dword addr;
	for (;;)
	{
		la = addr;
		addr = (dword)mm_palloc();
		if (fa == 0)
			fa = addr;
//		printf("addr = 0x%x\tcallnum = %u\tfree pages = %u\n", addr, callnum, mm_freemem()>>12);
		if (!addr)
			break;
		callnum++;
	}
	printf("#calls = %u\t", callnum);
	printf("mm_freemem() = %d (0x%x, %x)\n", mm_freemem(), mm_freemem(), mm_freemem());

	callnum = 0;
	addr = fa;

	for (;;)
	{
		mm_pfree(addr);
		addr += 4096;
		callnum++;
		if (addr > la)
			break;
	}

       	printf("#calls = %u\t", callnum);
	printf("mm_freemem() = %d (0x%x, %x)\n", mm_freemem(), mm_freemem(), mm_freemem());

	dword key = 0;
	for (;;)
	{
		key = kbdWaitKey();
		if ((key & 0xFF) > 2)	//key is not a control key
			putc(key);
	}
}

// main Interrupt Service Routine - handles all interrupts unless caught by kernel.asm
void isr(dword num)
{
	switch(num)
	{
	case 0x20:         		// IRQ0 - timer interrupt
		timer++;
		(*(byte *)(0xc00b8000))++;
		eoi();
		break;
	case 0x21:  			// IRQ1 - keyboard interrupt
		isr_keyboard();    	//isr_keybard() takes care of calling eoi()
		break;
	case 0x2C:			// IRQ12 - PS/2 mouse
		isr_mouse();
		eoi2();
		break;
	default:
		printf("Interrupt %d (0x%x) Unhandled!!\n", num, num);
		break;
	}
}