#include "assert.h"
#include "stdio.h"
#include "string.h"
#include "process.h"
#include "protect.h"
#include "type.h"
#include "trap.h"
#include "x86.h"
#include "time.h"
#include "keyboard.h"
#include "game.h"

/*
 * 三个测试函数，用户进程的执行流
 */
void TestA()
{
	int i = 0;
	u8 ch;
	while(1){
		if ((ch = getch()) != 255) {
			kprintf("%c", ch);
		}
		// kprintf("A%d.",i++);
		for (int j = 0 ; j < 5e7 ; j++)
			;//do nothing
	}
}

void TestB()
{
	int i = 0;
	while(1){
		// kprintf("B%d.",i++);
		for (int j = 0 ; j < 5e7 ; j++)
			;//do nothing
	}
}

void TestC()
{
	int i = 0;
	while(1){
		// kprintf("C%d.",i++);
		for (int j = 0 ; j < 5e7 ; j++)
			;//do nothing
	}
}

// 每个栈空间有4kb大
#define STACK_PREPROCESS	0x1000
#define STACK_TOTSIZE		STACK_PREPROCESS * PCB_SIZE
// 用户栈（直接在内核开一个临时数组充当）
char process_stack[STACK_TOTSIZE];
// 指向当前进程pcb的指针
PROCESS *p_proc_ready;
// pcb表
PROCESS	proc_table[PCB_SIZE];
#ifdef HAPPY_SNAKE
void (*entry[]) = {
	startGame
};
char pcb_name[][16] = {
	"SNAKE"
};
#else 
void (*entry[]) = {
	TestA,
	TestB,
	TestC,
};
char pcb_name[][16] = {
	"TestA",
	"TestB",
	"TestC",
};
#endif
/*
 * 内核的main函数
 * 用于初始化用户进程，然后将执行流交给用户进程
 */
void kernel_main()
{
	kprintf("---start kernel main---\n");

	PROCESS *p_proc = proc_table;
	char *p_stack = process_stack;

	for (int i = 0 ; i < PCB_SIZE ; i++, p_proc++) {
		strcpy(p_proc->p_name, pcb_name[i]);
		p_proc->regs.cs = (SELECTOR_FLAT_C & SA_RPL_MASK & SA_TI_MASK)
			| SA_TIL | RPL_USER;
		p_proc->regs.ds = (SELECTOR_FLAT_RW & SA_RPL_MASK & SA_TI_MASK)
			| SA_TIL | RPL_USER;
		p_proc->regs.es = (SELECTOR_FLAT_RW & SA_RPL_MASK & SA_TI_MASK)
			| SA_TIL | RPL_USER;
		p_proc->regs.fs = (SELECTOR_FLAT_RW & SA_RPL_MASK & SA_TI_MASK)
			| SA_TIL | RPL_USER;
		p_proc->regs.ss = (SELECTOR_FLAT_RW & SA_RPL_MASK & SA_TI_MASK)
			| SA_TIL | RPL_USER;
		p_proc->regs.gs = (SELECTOR_VIDEO & SA_RPL_MASK & SA_TI_MASK)
			| RPL_USER;
		
		p_proc->regs.eip = (u32)entry[i];
		p_stack += STACK_PREPROCESS;
		p_proc->regs.esp = (u32)p_stack;
		p_proc->regs.eflags = 0x1202; /* IF=1, IOPL=1 */
	}

	p_proc_ready = proc_table;

	change_8253Counter0(1000);
	enable_irq(CLOCK_IRQ);
	enable_irq(KEYBOARD_IRQ);
	restart();
	assert(0);
}