text: 
  /*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                              i8259.c
  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                                                      Forrest Yu, 2005
  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
  
  
  #include "type.h"
  #include "const.h"
  #include "protect.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. 
  }
  
  /*======================================================================*
                             spurious_irq
   *======================================================================*/
  PUBLIC void spurious_irq(int irq)
  {
  	disp_str("spurious_irq: ");
  	disp_int(irq);
  	disp_str("\n");
  }
  