swi_handler.c

一个简单的小型操作系统

/*****************************************************************************
 *
 * Module       : handler.c
 * Description  : provides the SWI handlers
 * Originator   : Andrew N. Sloss
 * History      :
 *	
 * November 4th 2001 Andrew N. Sloss
 * - corrected the header
 *
 * January 3rd 2002 Andrew N. Sloss
 * - added the bringup swi for trace and fatal error
 *
 * April 30th 2002 Andrew N. Sloss
 * - cleaned up for Integrator port
 *
 *****************************************************************************/

/*****************************************************************************
 * IMPORT
 *****************************************************************************/

#include "../../core/all.h"

/*****************************************************************************
 * MACROS
 *****************************************************************************/

/* Mode control bits .......................... */

#define SYSTEM 0x1f
#define SVC    0x13
#define USER   0x10

/* IRQ control bits ........................... */

#define IRQoN  0x40
#define IRQoFF 0xc0

/* Low-level FIQ debug ........................ */

void  modifyControlCPSR(unsigned int);
void  bringUpSetR8fiq(unsigned int);
void  bringUpSetR9fiq(unsigned int);
void  bringUpSetR10fiq(unsigned int);

extern unsigned int STATE;

/*****************************************************************************
 * ROUTINES
 *****************************************************************************/

/* -- events_swi_e7t_handler --------------------------------------------------
 *
 * Descriptions : handler the swi calls for the e7t
 * 
 * Parameters   : int swi_number - swi being called
 *              : SwiRegs *r	 - pointer to the SWI registers
 * Return       : CallBack pointer
 * Other        :
 *
 * This function should migrate to be generic
 *
 */

CallBack eventsSWIHandler(int swi_number, SwiRegs *r) 
{
  switch (swi_number) 
  {

  /**********************************************************************
   * SLOS SWI's 
   **********************************************************************/

  case /* SWI */ SLOS:

    switch (r->r[0]) 
    {
   /* -----------------------------------------------------------------
     * Low level Debug SWI for debugging before the operating system is
     * up and running. The following register hold the debug information.
     *
     *  r8fiq  - fatal error 
     *  r9fiq  - trace entry value
     *  r10fiq - trace exit value
     *
     * -----------------------------------------------------------------
     */
    
    case /* SWI */ BringUp_Trace: 

      switch (r->r[1])
      {
      case 123: /* ENTRY into routine ...................... */
      bringUpSetR9fiq (r->r[2]);
      break;

      case 321: /* EXIT into routine ....................... */
      bringUpSetR10fiq (r->r[2]);
      break;
      }

    break;

    case /* SWI */ BringUp_FatalError:   
    bringUpSetR8fiq (r->r[1]);
     
    fatalerror: goto fatalerror; /* setup infinite loop ... */
     
    break;

    /* -----------------------------------------------------------------
     * Device Driver SWI's for controlling and initializing device
     * drivers
     * -----------------------------------------------------------------
     */

    case /* SWI */ Event_IODeviceInit:
    ioInitializeDrivers ();
    r->r[0] = 1;
    r->r[1] = 2;
    break;
 
    default:

    /* ----------------------------------------------------------------
     * switch to SYSTEM mode and switch ON IRQ interrupts. 
     * ----------------------------------------------------------------
     */

    if (STATE!=1) 
    {
    /* Enable IRQ interrupts and switch to SYSTEM mode */	    
    asm volatile ("MSR CPSR_c,#0x5f");
    }

      switch (r->r[0]) 
      {
		  
      case /* SWI */ Event_IODeviceOpen:
      r->r[0] = (unsigned int) ioOpenDriver ((UID *)r->r[1],r->r[2],r->r[3]);
      break;

      case /* SWI */ Event_IODeviceClose:
      r->r[0] = (unsigned int) ioCloseDriver ((device_treestr *)r->r[1],(UID)r->r[2]);
      break;
	
      case /* SWI */ Event_IODeviceWriteByte:
      ioWriteByte ((device_treestr *)r->r[1],(UID)r->r[2],(BYTE)r->r[3]);
      break;
	
      case /* SWI */ Event_IODeviceReadByte:
      r->r[0] = (unsigned int) ioReadByte ((device_treestr *)r->r[1],(UID)r->r[2]);
      break;

      case /* SWI */ Event_IODeviceWriteBit:
      ioWriteBit ((device_treestr *)r->r[1],(UID)r->r[2],(UINT)r->r[3]);
      break;

      case /* SWI */ Event_IODeviceReadBit:
      r->r[0] = (unsigned int) ioReadBit ((device_treestr *)r->r[1],(UID)r->r[2]);
      break;

      case /* SWI */ Event_IODeviceWriteBlock:
      ioWriteBlock ((device_treestr *)r->r[1],(UID)r->r[2],(void *)r->r[3]);
      break;

      case /* SWI */ Event_IODeviceReadBlock:
      r->r[0] = (unsigned int) ioReadBlock ((device_treestr *)r->r[1],(UID)r->r[2]);
      break;
      
      }

    asm volatile ("MSR CPSR_c,#0xD3");
    }  
 }
return reportOK();
}