sched.c

自己正在开发的一个ARM9的操作系统。详细信息请访问www.another-prj.com

#include "../include/kernel/sched.h"
#include "../include/kernel/sys.h"
#include "../include/kernel/irq.h"
#include "../include/kernel/task.h"
#include "../include/kernel/typedef.h"
#include "../include/s3c2410/timer.h"
#include "../include/s3c2410/cpu.h"
#include "../include/mm/mm.h"
#include "../include/kernel/gui.h"

#define TASK_MEM_LIMIT	(1024*1024*32)
//#define _SCHEDULE_DEBUG
/*
 *	任务数组指针
 */
int volatile jiffies=0;

struct task_struct* task[NR_TASKS];
struct task_struct* current;
unsigned int last_pid;
extern struct irq_ctrl_object 	irq_ctrl_object;
extern void restorer();
extern int main(void);
#define FIRST_TASK	&task[0]
#define LAST_TASK	&task[NR_TASKS-1]

//得到user模式下的cpsr的值
#define USER ({ \
int reg; \
reg=read_cpsr();\
reg&=~(0x1f);\
reg|=UserMode;\	
reg; })

#define TASK0_CONTEXT_START	0
#define TASK0_CONTEXT_END	TASK0_CONTEXT_START+TASK_MEM_LIMIT-1

struct task_struct task_0={
	.state		=TASK_RUNNING,
	.priority	=15,
	.counter	=15,
	.signal		=0,
	.deal_signal	=0,
	.blocked	=0,
	
	.sigaction	={0,},

	.alarm		=0,
	.utime		=0,
	.stime		=0,
	.cutime		=0,
	.cstime		=0,
	.start_time	=0,
	
	.exit_code	=0,
	.context_start	=TASK0_CONTEXT_START,
	.context_end	=TASK0_CONTEXT_END,
	.pid		=0,
	.father		=0,

	.cpu_registers={
/* r0   */	.r0=0,
/* r1   */	.r1=0,
/* r2   */	.r2=0,
/* r3   */	.r3=0,
/* r4   */	.r4=0,
/* r5   */	.r5=0,
/* r6   */	.r6=0,
/* r7   */	.r7=0,
/* r8   */	.r8=0,
/* r9   */	.r9=0,
/* r10  */	.r10=0,
/* r11  */	.r11=0,
/* r12  */	.r12=0,
/* sp   */	.sp=TASK0_CONTEXT_START+TASK_MEM_LIMIT-4,
/* lr   */	.lr=0,
/* pc   */	.pc=0,
/* cpsr */	.cpsr=0
	},
	.next=0
};

#define BLOCK(n) ((n)*32*512)

//设置系统的时钟滴答
void set_sched_freq(unsigned int freq)
{
	timer_enable(TIMER_0,freq);

}

void clean_stack(char *addr)
{
	int i;
	for(i=0;i<1024*1024;i++)
	{
		addr[i]='\0';
	}
}

void tasks_init()
{
	int i;
	unsigned int *tmp;

	for(i=0;i<NR_TASKS;i++)
	{
		task[i]=0;
	}


	last_pid=0;
	task_0.cpu_registers.cpsr=USER;

	task[0]=&task_0;
	current=task[0];

	clean_stack((current->context_end)-1024*1024);
	nf_read(BLOCK(10),current->context_start,1024*12);

	tmp=&((current)->cpu_registers);
	jiffies=0;

	set_sched_freq(50);	//时钟滴答为50赫兹
	enable_watchdog();


	set_process_id(0);//设置process Identifier
	switch_cpu_mode(UserMode);//进入用户模式

	//启动0号进程
	asm volatile(
		"ldr r0,%0 \n\t"
		"ldmib r0!,{r1-r15} \n\t"
		:
		:"m"(tmp)
	);
}



void schedule(struct cpu_registers *regs)
{
	struct task_struct** p;

	feed_dog();
	//对已存在的任务进行信号处理(未完成)
	for(p=FIRST_TASK;p<LAST_TASK;p++)
	{
		if(*p)
		{
			//get_task_state(*p);
		}
	}

	//下面进行任务调度(未完成)

}

/*
void save_cpu_context(unsigned int *regs)
{
	unsigned int *p_reglist=&p_current_task->cpu_registers.r0;
	int regid;
	for(regid=0;regid<REGS;regid++)
	{
		p_reglist[regid]=regs[regid];
	}

	p_reglist[PC]=regs[PC]-4;
}

void load_cpu_context(unsigned int *regs)
{
	unsigned int *p_reglist=&p_current_task->cpu_registers.r0;
	int regid;
	for(regid=0;regid<REGS;regid++)
	{
		regs[regid]=p_reglist[regid];
	}
	regs[PC]=p_reglist[PC]+4;
}

*/



/*
 *	任务切换函数
 *	我已经尽可能地让它简单了，我很喜欢这段代码，一来它能把任务切
 *	换的工作做得很好，二来它也是这个多任务系统的基础

void schedule(struct cpu_registers *regs)
{
	feed_dog();
	p_current_task->alarm--;

	if(p_current_task->alarm<=0)
	{

		save_cpu_context(regs);

		p_last_task=p_current_task;
		
		if((p_current_task=p_current_task->next)==NULL)
		{
			p_current_task=task_queue_head.next;
		}
		
		p_current_task->state=RUNABLE;
		
		p_last_task->state=READY;
		p_last_task->alarm=p_last_task->priority;
		
		load_cpu_context(regs);
	}
}

*/

/*
 *	查看任务p当前的详细信息
 *
 */
void dump_task(struct task_struct* p)
{
	int nr;
	
	for(nr=0;nr<NR_TASKS;nr++)
	{
		if(p==task[nr])
			break;
	}

	printk("task %d details\n",nr);
	printk("handle:0x%08x	next:0x%08x\n",p,p->next);

	printk("state\t\tpriority\tcounter\t\tsignal\t\tblocked\n0x%08x\t0x%08x\t0x%08x\t0x%08x\t0x%08x\n", 
		p->state,p->priority,p->counter,p->signal,p->blocked);

	printk("utime\t\tstime\t\tcutime\t\tcstime\t\tstart_time\n0x%08x\t0x%08x\t0x%08x\t0x%08x\t0x%08x\n", 
		p->utime,p->stime,p->cutime,p->cstime,p->start_time);
	
	printk("alarm\t\texit_code\tcontext_start\tcontext_end\tpid\n0x%08x\t0x%08x\t0x%08x\t0x%08x\t0x%08x\n", 
		p->alarm,p->exit_code,p->context_start,p->context_end,p->pid);
	printk("father\n0x%08x\n",p->father);
	
	printk("r0\t\tr1\t\tr2\t\tr3\t\tr4\n0x%08x\t0x%08x\t0x%08x\t0x%08x\t0x%08x\n",
		p->cpu_registers.r0,p->cpu_registers.r1,p->cpu_registers.r2,
		p->cpu_registers.r3,p->cpu_registers.r4);
	printk("r5\t\tr6\t\tr7\t\tr8\t\tr9\n0x%08x\t0x%08x\t0x%08x\t0x%08x\t0x%08x\n",
		p->cpu_registers.r5,p->cpu_registers.r6,p->cpu_registers.r7,
		p->cpu_registers.r8,p->cpu_registers.r9);	
	printk("r10\t\tr11\t\tr12\t\tsp\t\tlr\n0x%08x\t0x%08x\t0x%08x\t0x%08x\t0x%08x\n",
		p->cpu_registers.r10,p->cpu_registers.r11,p->cpu_registers.r12,
		p->cpu_registers.sp,p->cpu_registers.lr);	
	printk("pc\t\tcpsr\n0x%08x\t0x%08x\n\n",p->cpu_registers.pc,p->cpu_registers.cpsr);
	
}

void get_task_state(struct task_struct* p)
{
	printk("task %d ",p->pid);
	switch(p->state)
	{
		case TASK_RUNNING:
			printk(" RUNNING\n");
			break;
				
		case TASK_INTERRUPTIBLE:
			printk(" INTERRUPTIBLE\n");
			break;
					
		case TASK_UNINTERRUPTIBLE:
			printk(" UNINTERRUPTIBLE\n");
			break;
				
		case TASK_ZOMBIE:
			printk(" ZOMBIE\n");
			break;
				
		case TASK_STOPPED:
			printk(" STOPPED\n");
			break;
	}
}