main.c

《自己动手写操作系统》于渊（著） 一书的源代码

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                            main.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                                                    Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

#include "type.h"
#include "const.h"
#include "protect.h"
#include "proto.h"
#include "string.h"
#include "proc.h"
#include "global.h"


/*======================================================================*
                            tinix_main
 *======================================================================*/
PUBLIC int tinix_main()
{
	disp_str("-----\"tinix_main\" begins-----\n");

	PROCESS* p_proc	= proc_table;
	p_proc->ldt_sel	= SELECTOR_LDT_FIRST;
	memcpy(&p_proc->ldts[0], &gdt[SELECTOR_KERNEL_CS >> 3], sizeof(DESCRIPTOR));
	p_proc->ldts[0].attr1 = DA_C | PRIVILEGE_TASK << 5;	// change the DPL
	memcpy(&p_proc->ldts[1], &gdt[SELECTOR_KERNEL_DS >> 3], sizeof(DESCRIPTOR));
	p_proc->ldts[1].attr1 = DA_DRW | PRIVILEGE_TASK << 5;	// change the DPL
	p_proc->regs.cs		= ((8 * 0) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
	p_proc->regs.ds		= ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
	p_proc->regs.es		= ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
	p_proc->regs.fs		= ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
	p_proc->regs.ss		= ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
	p_proc->regs.gs		= (SELECTOR_KERNEL_GS & SA_RPL_MASK) | RPL_TASK;
	p_proc->regs.eip	= (t_32)TestA;
	p_proc->regs.esp	= (t_32) task_stack + STACK_SIZE_TOTAL;
	p_proc->regs.eflags	= 0x1202;	// IF=1, IOPL=1, bit 2 is always 1.

	p_proc_ready	= proc_table; 
	restart();


	while(1){}
}

/*======================================================================*
                               TestA
 *======================================================================*/
void TestA()
{
	int i = 0;
	while(1){
		disp_str("A");
		disp_int(i++);
		disp_str(".");
		delay(1);
	}
}