i8259.c

这是《自己动手写操作系统》的原文件和代码

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                            i8259.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                                                    Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/


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


/*======================================================================*
                            init_8259A
 *======================================================================*/
PUBLIC void init_8259A()
{
	out_byte(INT_M_CTL,	0x11);			// Master 8259, ICW1.
	out_byte(INT_S_CTL,	0x11);			// Slave  8259, ICW1.
	out_byte(INT_M_CTLMASK,	INT_VECTOR_IRQ0);	// Master 8259, ICW2. 设置 '主8259' 的中断入口地址为 0x20.
	out_byte(INT_S_CTLMASK,	INT_VECTOR_IRQ8);	// Slave  8259, ICW2. 设置 '从8259' 的中断入口地址为 0x28
	out_byte(INT_M_CTLMASK,	0x4);			// Master 8259, ICW3. IR2 对应 '从8259'.
	out_byte(INT_S_CTLMASK,	0x2);			// Slave  8259, ICW3. 对应 '主8259' 的 IR2.
	out_byte(INT_M_CTLMASK,	0x1);			// Master 8259, ICW4.
	out_byte(INT_S_CTLMASK,	0x1);			// Slave  8259, ICW4.

	out_byte(INT_M_CTLMASK,	0xFF);	// Master 8259, OCW1. 
	out_byte(INT_S_CTLMASK,	0xFF);	// Slave  8259, OCW1. 

	int i;
	for(i=0;i<NR_IRQ;i++){
		irq_table[i]	= spurious_irq;
	}
}

/*======================================================================*
                            put_irq_handler
 *======================================================================*/
PUBLIC void put_irq_handler(int irq, t_pf_irq_handler handler)
{
	disable_irq(irq);
	irq_table[irq] = handler;
}

/*======================================================================*
                           spurious_irq
 *======================================================================*/
PUBLIC void spurious_irq(int irq)
{
	disp_str("spurious_irq: ");
	disp_int(irq);
	disp_str("\n");
}