#ifndef _SCHED_H#define _SCHED_H#define NR_TASKS 64#define HZ 100#define FIRST_TASK task[0]#define LAST_TASK task[NR_TASKS-1]#include <linux/head.h>#include <linux/fs.h>#include <linux/mm.h>#if (NR_OPEN > 32)#error "Currently the close-on-exec-flags are in one word, max 32 files/proc"#endif#define TASK_RUNNING		0#define TASK_INTERRUPTIBLE	1#define TASK_UNINTERRUPTIBLE	2#define TASK_ZOMBIE		3#define TASK_STOPPED		4#ifndef NULL#define NULL ((void *) 0)#endifextern int copy_page_tables(unsigned long from, unsigned long to, long size);extern int free_page_tables(unsigned long from, long size);extern void sched_init(void);extern void schedule(void);extern void trap_init(void);extern void panic(const char * str);extern int tty_write(unsigned minor,char * buf,int count);typedef int (*fn_ptr)();struct i387_struct {	long	cwd;	long	swd;	long	twd;	long	fip;	long	fcs;	long	foo;	long	fos;	long	st_space[20];	/* 8*10 bytes for each FP-reg = 80 bytes */};struct tss_struct {	long	back_link;	/* 16 high bits zero */	long	esp0;	long	ss0;		/* 16 high bits zero */	long	esp1;	long	ss1;		/* 16 high bits zero */	long	esp2;	long	ss2;		/* 16 high bits zero */	long	cr3;	long	eip;	long	eflags;	long	eax,ecx,edx,ebx;	long	esp;	long	ebp;	long	esi;	long	edi;	long	es;		/* 16 high bits zero */	long	cs;		/* 16 high bits zero */	long	ss;		/* 16 high bits zero */	long	ds;		/* 16 high bits zero */	long	fs;		/* 16 high bits zero */	long	gs;		/* 16 high bits zero */	long	ldt;		/* 16 high bits zero */	long	trace_bitmap;	/* bits: trace 0, bitmap 16-31 */	struct i387_struct i387;};struct task_struct {/* these are hardcoded - don't touch */	long state;	/* -1 unrunnable, 0 runnable, >0 stopped */	long counter;	long priority;	long signal;	fn_ptr sig_restorer;	fn_ptr sig_fn[32];/* various fields */	int exit_code;	unsigned long end_code,end_data,brk,start_stack;	long pid,father,pgrp,session,leader;	unsigned short uid,euid,suid;	unsigned short gid,egid,sgid;	long alarm;	long utime,stime,cutime,cstime,start_time;	unsigned short used_math;/* file system info */	int tty;		/* -1 if no tty, so it must be signed */	unsigned short umask;	struct m_inode * pwd;	struct m_inode * root;	unsigned long close_on_exec;	struct file * filp[NR_OPEN];/* ldt for this task 0 - zero 1 - cs 2 - ds&ss */	struct desc_struct ldt[3];/* tss for this task */	struct tss_struct tss;};/* *  INIT_TASK is used to set up the first task table, touch at * your own risk!. Base=0, limit=0x9ffff (=640kB) */#define INIT_TASK \/* state etc */	{ 0,15,15, \/* signals */	0,NULL,{(fn_ptr) 0,}, \/* ec,brk... */	0,0,0,0,0, \/* pid etc.. */	0,-1,0,0,0, \/* uid etc */	0,0,0,0,0,0, \/* alarm */	0,0,0,0,0,0, \/* math */	0, \/* fs info */	-1,0133,NULL,NULL,0, \/* filp */	{NULL,}, \	{ \		{0,0}, \/* ldt */	{0x9f,0xc0fa00}, \		{0x9f,0xc0f200}, \	}, \/*tss*/	{0,PAGE_SIZE+(long)&init_task,0x10,0,0,0,0,(long)&pg_dir,\	 0,0,0,0,0,0,0,0, \	 0,0,0x17,0x17,0x17,0x17,0x17,0x17, \	 _LDT(0),0x80000000, \		{} \	}, \}extern struct task_struct *task[NR_TASKS];extern struct task_struct *last_task_used_math;extern struct task_struct *current;extern long volatile jiffies;extern long startup_time;#define CURRENT_TIME (startup_time+jiffies/HZ)extern void sleep_on(struct task_struct ** p);extern void interruptible_sleep_on(struct task_struct ** p);extern void wake_up(struct task_struct ** p);/* * Entry into gdt where to find first TSS. 0-nul, 1-cs, 2-ds, 3-syscall * 4-TSS0, 5-LDT0, 6-TSS1 etc ... */#define FIRST_TSS_ENTRY 4#define FIRST_LDT_ENTRY (FIRST_TSS_ENTRY+1)#define _TSS(n) ((((unsigned long) n)<<4)+(FIRST_TSS_ENTRY<<3))#define _LDT(n) ((((unsigned long) n)<<4)+(FIRST_LDT_ENTRY<<3))#define ltr(n) __asm__("ltr %%ax"::"a" (_TSS(n)))#define lldt(n) __asm__("lldt %%ax"::"a" (_LDT(n)))#define str(n) \__asm__("str %%ax\n\t" \	"subl %2,%%eax\n\t" \	"shrl $4,%%eax" \	:"=a" (n) \	:"a" (0),"i" (FIRST_TSS_ENTRY<<3))/* *	switch_to(n) should switch tasks to task nr n, first * checking that n isn't the current task, in which case it does nothing. * This also clears the TS-flag if the task we switched to has used * tha math co-processor latest. */#define switch_to(n) {\struct {long a,b;} __tmp; \__asm__("cmpl %%ecx,_current\n\t" \	"je 1f\n\t" \	"xchgl %%ecx,_current\n\t" \	"movw %%dx,%1\n\t" \	"ljmp %0\n\t" \	"cmpl %%ecx,%2\n\t" \	"jne 1f\n\t" \	"clts\n" \	"1:" \	::"m" (*&__tmp.a),"m" (*&__tmp.b), \	"m" (last_task_used_math),"d" _TSS(n),"c" ((long) task[n])); \}#define PAGE_ALIGN(n) (((n)+0xfff)&0xfffff000)#define _set_base(addr,base) \__asm__("movw %%dx,%0\n\t" \	"rorl $16,%%edx\n\t" \	"movb %%dl,%1\n\t" \	"movb %%dh,%2" \	::"m" (*((addr)+2)), \	  "m" (*((addr)+4)), \	  "m" (*((addr)+7)), \	  "d" (base) \	:"dx")#define _set_limit(addr,limit) \__asm__("movw %%dx,%0\n\t" \	"rorl $16,%%edx\n\t" \	"movb %1,%%dh\n\t" \	"andb $0xf0,%%dh\n\t" \	"orb %%dh,%%dl\n\t" \	"movb %%dl,%1" \	::"m" (*(addr)), \	  "m" (*((addr)+6)), \	  "d" (limit) \	:"dx")#define set_base(ldt,base) _set_base( ((char *)&(ldt)) , base )#define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , (limit-1)>>12 )#define _get_base(addr) ({\unsigned long __base; \__asm__("movb %3,%%dh\n\t" \	"movb %2,%%dl\n\t" \	"shll $16,%%edx\n\t" \	"movw %1,%%dx" \	:"=d" (__base) \	:"m" (*((addr)+2)), \	 "m" (*((addr)+4)), \	 "m" (*((addr)+7))); \__base;})#define get_base(ldt) _get_base( ((char *)&(ldt)) )#define get_limit(segment) ({ \unsigned long __limit; \__asm__("lsll %1,%0\n\tincl %0":"=r" (__limit):"r" (segment)); \__limit;})#endif