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/////////////////////////////////////////////////
// Author: 	Rafael Angelo Gardini
// File: 	k_main.c
// Description:	Kernel main
// Last update:	21/06/2012
/////////////////////////////////////////////////

#include "../headers/io/stdio.h"
#include "../headers/io/video.h"
#include "../headers/memory/mm.h"
#include "../headers/process/process.h"
#include "../headers/system/fpu.h"
#include "../headers/system/gdt.h"
#include "../headers/system/idt.h"
#include "../headers/system/irq.h"
#include "../headers/system/isr.h"
#include "../headers/system/kernel.h"
#include "../headers/system/timer.h"

#ifndef K_MAIN

void task0(void)
{
	k_printf("task0\n");

	for(;;);

}

void task1(void)
{
	k_printf("task1\n");

	for(;;);
}

void task2(void)
{
	k_printf("task2\n");

	for(;;);
}

void task3(void)
{
	k_printf("task3\n");

	for(;;);
}

void k_main() 
{
	k_cli_irq();

	k_install_memory();

	k_install_video();

	k_install_gdt();	
	
	k_install_idt();

	k_install_irq();

	k_install_isr();

	k_install_fpu();

	k_install_timer();

	k_install_process();

	k_info_kernel();

	k_sti_irq();

	//---------------------------------------------
	k_create_process(task0);
	k_create_process(task1);
	k_create_process(task2);
	k_create_process(task3);
	//---------------------------------------------

	k_enable_schedule_process();

	k_loop_kernel();
}

#endif

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/////////////////////////////////////////////////
// Author: 	Rafael Angelo Gardini
// File: 	process.h
// Description:	Process functions
// Last update:	30/09/2013
/////////////////////////////////////////////////

#include "../../headers/io/stdio.h"
#include "../../headers/memory/mm.h"
#include "../../headers/process/process.h"
#include "../../headers/system/irq.h"

#ifndef PROCESS
#define PROCESS

void k_install_process()
{
	process.storepid = 0;
	process.enable = 0;

	process.running = MEMORY_NULL;
	process.task = MEMORY_NULL;

	k_printf("Install process management sucess...\n");
}

int k_create_stack(void (*task)(void))
{
	int stackptr = (int)k_malloc(STACK_SIZE) + STACK_SIZE ;

	unsigned int * stack = (unsigned int*)stackptr;

	*--stack = 0x202;

	*--stack = 0x08;

	*--stack = (unsigned int) task;

	*--stack = 0;
	*--stack = 0;
	*--stack = 0;
	*--stack = 0;
	*--stack = 0;
	*--stack = 0;
	*--stack = 0;
	*--stack = 0;

	*--stack = 0x10;
	*--stack = 0x10;
	*--stack = 0x10;
	*--stack = 0x10;

	return (unsigned int) stack;
}

void k_create_process(void (*task)(void))
{
	k_cli_irq();

	TASK * newtask = (TASK *) k_malloc(sizeof(TASK));

	newtask->stack = k_create_stack(task);

	newtask->status = STOPPED;
	newtask->task = task;
	newtask->pid = process.storepid;

	k_printf("CREATE PID [%d] STACK: [%d] TASK: [%d]\n", newtask->pid, newtask->stack, newtask->task);

	if (process.task == MEMORY_NULL)
	{
		process.task = newtask;
		process.task->next = MEMORY_NULL;
	}
	else
	{
		newtask->next = process.task;
		process.task = newtask;
	}

	process.storepid++;

	k_sti_irq();
}

void k_enable_schedule_process()
{
	process.enable = 1;
}

int k_schedule_process(int context)
{
	if (process.task == MEMORY_NULL)
	{
		return context;
	}

	if (process.running == MEMORY_NULL)
	{
		process.running = process.task;
	}
	else
	{
		process.running->stack = context;

		if (process.running->next != MEMORY_NULL)
		{
			process.running = process.running->next;
		}
		else
		{
			process.running = process.task;
		}
	}

	k_printf("PID %d CONTEXT: %d STACK %d\n", process.running->pid, context, process.running->stack);

	return process.running->stack;
}

void k_kill_process(int pid)
{
	TASK * index = MEMORY_NULL;

	for (index = process.task; index != MEMORY_NULL; index = index->next)
	{
		if (pid == index->pid)
		{
			index->status = KILLED;
		}
	}
}

#endif

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[BITS 32]
extern k_schedule_process

global k_switch_process

k_switch_process:
                pusha
                push ds
                push es
                push fs
                push gs

                mov eax, 0x10
                mov ds, eax
                mov es, eax
                mov fs, eax
                mov gs, eax

                mov eax, esp

                push eax
                call k_schedule_process
                mov esp, eax

                mov al, 0x20
                out 0x20, al

                pop gs
                pop fs
                pop es
                pop ds
                popa

                iret

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LD = i586-elf-ld -L bin -T $(LNKS) -Map kernel.map