excep_api.h

MIPS下的boottloader yamon 的源代码

#ifndef EXCEP_API_H
#define EXCEP_API_H

/************************************************************************
 *
 *  excep_api.h
 *
 *  The 'EXCEP' module implements a first level exception and
 *  interrupt handling and an API to register user defined
 *  exception and interrupt service routines (ESR & ISR).
 *
 *  Interrupt Service Routine registration is possible at
 *
 *    a) The MIPS CPU SW/HW interrupt level (CPU-ISR) : 0..7
 *    b) The Interrupt controller level     (IC-ISR)  : (platform specific)
 *
 *  Registration of ISR's imply enabling of the corresponding
 *  interrupt MASK bit in the CPU or the interrupt controller.
 *
 *  Interrupt Service Routine handling is executed in a prioritized
 *  scheme. First, registered handlers at CPU interrupt level are
 *  called, second, registered handlers at interrupt controller
 *  level are called.
 *
 *  Public API offers:
 *
 *  1) EXCEP_init()
 *  2) EXCEP_register_esr()
 *  3) EXCEP_register_cpu_isr()
 *  4) EXCEP_register_ic_isr()
 *  5) EXCEP_print_context()
 *
 *
 * ######################################################################
 *
 * Copyright (c) 1999-2000 MIPS Technologies, Inc. All rights reserved. 
 * 
 * Unpublished rights reserved under the Copyright Laws of the United States of 
 * America. 
 * 
 * This document contains information that is proprietary to MIPS Technologies, 
 * Inc. ("MIPS Technologies"). Any copying, modifying or use of this information 
 * (in whole or in part) which is not expressly permitted in writing by MIPS 
 * Technologies or a contractually-authorized third party is strictly 
 * prohibited. At a minimum, this information is protected under unfair 
 * competition laws and the expression of the information contained herein is 
 * protected under federal copyright laws. Violations thereof may result in 
 * criminal penalties and fines. 
 * MIPS Technologies or any contractually-authorized third party reserves the 
 * right to change the information contained in this document to improve 
 * function, design or otherwise. MIPS Technologies does not assume any 
 * liability arising out of the application or use of this information. Any 
 * license under patent rights or any other intellectual property rights owned 
 * by MIPS Technologies or third parties shall be conveyed by MIPS Technologies 
 * or any contractually-authorized third party in a separate license agreement 
 * between the parties. 
 * The information contained in this document constitutes one or more of the 
 * following: commercial computer software, commercial computer software 
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 * any related documentation of any kind, including related technical data or 
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 * Acquisition Regulation 12.212 for civilian agencies and Defense Federal 
 * Acquisition Regulation Supplement 227.7202 for military agencies. The use of 
 * this information by the Government is further restricted in accordance with 
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 *
 ************************************************************************/


/************************************************************************
 *    Include files
 ************************************************************************/

#include <sysdefs.h>
#include <syserror.h>
#include <gdb_stub.h>


#ifndef _ASSEMBLER_


/************************************************************************
 *  System Definitions
*************************************************************************/

/*  Number used by the below registration functions in order to register
 *  a default handler.
 */
#define EXCEP_DEFAULT_HANDLER	0xfffffff0

/*  Number used by the below registration functions in order to register
 *  an EJTAG debug exception handler.
 */
#define EXCEP_EJTAG_HANDLER	0xfffffff1

/* Registered ISR */
typedef void (*t_EXCEP_isr)(void *data);

/* Registered ESR */
typedef void (*t_EXCEP_esr)(void);

/* Function registered to be called by first level exception handler */
typedef void (*t_EXCEP_first_level_excep)(UINT32 code, bool ejtag);

/* Entry point called by ESRs wishing to pass control back to YAMON */
typedef void (*t_EXCEP_retfunc)(void);

/* Handle used for deregistration of ISR/ESR */
typedef void *t_EXCEP_ref;

/************************************************************************
 *   EXCEP ERROR completion codes
*************************************************************************/


typedef enum EXCEP_error_ids
{

    ERROR_EXCEP_ILLEGAL_EXCEPTION       /* Exception ID is unknown      */
                = ERROR_EXCEP,
    ERROR_EXCEP_ILLEGAL_HANDLER,        /* Handler reference is NULL    */
    ERROR_EXCEP_ALREADY_REGISTERED,     /* Exception has been registered */
    ERROR_EXCEP_ILLEGAL_INTERRUPT,      /* Interrupt source is unknown  */
    ERROR_EXCEP_NO_SPACE,               /* Too many handlers registered */


/******* ADD NEW IO ERROR TAGS JUST BEFORE THIS LINE ONLY *******/

} t_EXCEP_error_ids;


/************************************************************************
 *    Public variables
 ************************************************************************/

extern t_gdb_regs  EXCEP_gdb_regs;
extern bool	   EXCEP_ejtag;

/************************************************************************
 *   Public functions
 ************************************************************************/


/************************************************************************
 *
 *                          EXCEP_init
 *  Description :
 *  -------------
 *
 *  Initializes the 'EXCEP' module.
 *  
 *  Parameters :
 *  ------------
 *
 *  None
 *
 *  Return values :
 *  ---------------
 *
 *  'OK'(=0)
 *
 ************************************************************************/
INT32 
EXCEP_init( void );


/************************************************************************
 *
 *                          EXCEP_register_esr
 *  Description :
 *  -------------
 *
 *  Registers an exception handler, also known as an "Exception Service
 *  Routine" (ESR) for the specified exception.
 *  
 *  Two special exception IDs are defined :
 *      EXCEP_DEFAULT_HANDLER used for a default handler.
 *      EXCEP_EJTAG_HANDLER used for EJTAG exceptions.
 *	
 *  The default handler is called if no other handler is registered
 *  for an exception. If no default handler is registered, a static
 *  (i.e. not registered) "super default" function is invoked.
 *  This function prints out the registers and halts.
 *
 *  Deregistration of a handler may be be done by calling this function 
 *  with 'handler' set to NULL.
 *  Handlers can also be deregistered using EXCEP_deregister_esr.
 *
 *  A handler may be registered even if a previously registered 
 *  handler has not been deregistered. In this case the previously
 *  registered handler is lost.
 *
 *  In case an ESR does not want to handle the exception, it may
 *  call the return function passed in the 'retfunc' parameter.
 *
 *  Case 1 : 'retfunc' called by ESR registered for the INTERRUPT exception.
 *
 *  We assume an application has registered this ESR and wants
 *  YAMON to process the (remaining) interrupts.
 *  So, we call the ESR, which is used by YAMON for handling 
 *  interrupt exceptions, i.e. interrupt_sr().
 *
 *  Case 2 :  'retfunc' called by an ESR registered for a specific
 *	      exception (not INTERRUPT).
 *
 *  Default handling will be done.
 *
 *  Case 3 : 'retfunc' is called by the ESR registered as default handler.
 *
 *  The exception will be handled as though no ESR is registered 
 *  (i.e. the "super default" function is called).
 *
 *  Parameters :
 *  ------------
 *
 *  'exception', IN,    Exception code (C0_CAUSE_CODE_xxx).
 *			or EXCEP_DEFAULT_HANDLER for a default handler
 *			or EXCEP_EJTAG_HANDLER for ejtag exceptions.
 *  'raw',	 IN     If TRUE, ESR will get called with registers
 *			in the state they were when the exception occurred.
 *			This includes all CP0 registers and CPU registers
 *			$0..$31, except for k0,k1 ($26,$27).
 *  'handler',   IN,    Function pointer for ESR.
 *  'ref',	 OUT,   Handle used for deregistration of handler.
 *  'retfunc',	 OUT,   Pointer to function pointer for the return
 *			function described above.
 *
 *  Return values :
 *  ---------------
 *
 *  'OK'(=0)
 *  'ERROR_EXCEP_ILLEGAL_EXCEPTION':  Exception ID is unknown
 *
 ************************************************************************/
INT32 
EXCEP_register_esr(
    UINT32          exception,	     /* Exception identification	*/
    bool	    raw,	     /* Pass on unmodified registers	*/
    t_EXCEP_esr     handler,	     /* ESR to be registered		*/
    t_EXCEP_ref     *ref,	     /* OUT : Handle for deregistration */
    t_EXCEP_retfunc *retfunc );      /* OUT : Return function		*/


/************************************************************************
 *
 *                          EXCEP_deregister_esr
 *  Description :
 *  -------------
 *
 *  Deregisters exception handler
 *  
 *  Parameters :
 *  ------------
 *
 *  'ref',	 IN,   Handle obtained when calling EXCEP_register_esr
 *