start12.c

freescale 协处理器应用相关实例

/*****************************************************
      start12.c - standard startup code
   The startup code may be optimized to special user requests
 ----------------------------------------------------
   Copyright (c) Metrowerks, Basel, Switzerland
               All rights reserved

Note: ROM libraries are not implemented in this startup code
Note: C++ destructors of global objects are NOT yet supported in the HIWARE Object File Format.
      To use this feature, please build your application with the ELF object file format.
      
      
*MG* >>>>>>>>>>>>>>>>> 21/09/06 Martyn Gallop, MCD Applications, EKB, FSL <<<<<<<<<<<<<<<<<<<<< 
Minor modification to move the _Startup routine to the beginning of the file so that
it gets built before the Init routine (added a prototype for Init). This results in the reset
vector being at the start of code in this module rather than in the middle. It also means that
the start vector does not change when using the __ONLY_INIT_SP switch.
.      
      
 *****************************************************/
/*lint -esym(750, __NO_FLAGS_OFFSET, __NO_MAIN_OFFSET, __NO_STACKOFFSET_OFFSET) */
/* these macros remove some unused fields in the startup descriptor */
#define __NO_FLAGS_OFFSET       /* we do not need the flags field in the startup data descriptor */
#define __NO_MAIN_OFFSET        /* we do not need the main field in the startup data descriptor */
#define __NO_STACKOFFSET_OFFSET /* we do not need the stackOffset field in the startup data descriptor */

/*#define __BANKED_COPY_DOWN : allow to allocate .copy in flash area */
#if defined(__BANKED_COPY_DOWN) && (!defined(__HCS12X__) || !defined(__ELF_OBJECT_FILE_FORMAT__))
#error /* the __BANKED_COPY_DOWN switch is only supported for the HCS12X with ELF */
       /* (and not for the HC12, HCS12 or for the HIWARE object file format) */
#endif

#include "hidef.h"
#include "start12.h"
#include "s12x_peripherals.h"


/***************************************************************************/
/* Macros to control how the startup code handles the COP:                 */
/* #define _DO_FEED_COP_  : do feed the COP                                */
/* #define _DO_ENABLE_COP_: do enable the COP                              */
/* #define _DO_DISABLE_COP_: disable the COP                               */
/* Without defining any of these, the startup code does NOT handle the COP */
/***************************************************************************/
/* __ONLY_INIT_SP define:                                                  */
/* This define selects an shorter version of the startup code              */
/* which only loads the stack pointer and directly afterwards calls        */
/* main. This version does however NOT initialized global variables        */
/* (So this version is not ANSI compliant!)                                */
/***************************************************************************/
/* __FAR_DATA define:                                                      */
/* By default, the startup code only supports to initialize the default    */
/* kind of memory. If some memory is allocated far in the small or banked  */
/* memory model, then the startup code only supports to initialize this    */
/* memory blocks if __FAR_DATA is defined. If __FAR_DATA is not defined,   */
/* then the linker will issue a message like                               */
/* "L1128: Cutting value _Range beg data member from 0xF01000 to 0x1000"   */
/* and this startup code writes to the cutted address                      */
/***************************************************************************/
/* __BANKED_COPY_DOWN define:                                              */
/* by default, the startup code assumes that the startup data structure    */
/* _startupData, the zero out areas and the .copy section are all 		   */
/* allocated in NON_BANKED memory. Especially the .copy section can be     */
/* if there are many or large RAM areas to initialize.                     */  
/* for the HCS12X, which also copies the XGATE RAM located code via .copy  */
/* section, the startup code supports to allocate .copy in a banked flash  */
/* The placement of .copy in the prm file has to be adapted when adding or */
/* removing the this macro.                                                */
/* Note: This macro is only supported for the HCS12X and when using ELF    */
/***************************************************************************/

#ifdef __cplusplus
#define __EXTERN_C  extern "C"
#else
#define __EXTERN_C
#endif

__EXTERN_C void main(void); /* prototype of main function */
static void Init(void);     /* prototype of Init function - MG 21/09/06 */

#ifndef __ONLY_INIT_SP
#pragma DATA_SEG __NEAR_SEG STARTUP_DATA /* _startupData can be accessed using 16 bit accesses. */
/* This is needed because it contains the stack top, and without stack, far data cannot be accessed */
/*lint -e1065 */
struct _tagStartup _startupData;  /*   read-only: */
                                  /*   _startupData is allocated in ROM and */
                                  /*   initialized by the linker */
/*lint +e1065 */
#pragma DATA_SEG DEFAULT
#endif /* __ONLY_INIT_SP */

#if defined(FAR_DATA) && (!defined(__HCS12X__) || defined(__BANKED_COPY_DOWN))
#include "non_bank.sgm"
/* the init function must be in non banked memory if banked variables are used */
/* because _SET_PAGE is called, which may change any page register. */

__EXTERN_C void _SET_PAGE(void);  /* the inline assembler needs a prototype */
                                  /* this is a runtime routine with a special */
                                  /* calling convention, do not use it in c code! */
#else
#include "default.sgm"
#endif /* defined(FAR_DATA) && (!defined(__HCS12X__) || defined(__BANKED_COPY_DOWN)) */


/* define value and bits for Windef Register */
#ifdef HC812A4
#define WINDEF (*(volatile unsigned char*) 0x37)
#if defined( __BANKED__) || defined(__LARGE__) || defined(__PPAGE__)
#define __ENABLE_PPAGE__ 0x40
#else
#define __ENABLE_PPAGE__ 0x0
#endif
#if defined(__DPAGE__)
#define __ENABLE_DPAGE__ 0x80
#else
#define __ENABLE_DPAGE__ 0x0
#endif
#if defined(__EPAGE__)
#define __ENABLE_EPAGE__ 0x20
#else
#define __ENABLE_EPAGE__ 0x0
#endif
#endif  /* HC812A4 */

#ifdef _HCS12_SERIALMON
      /* for Monitor based software remap the RAM & EEPROM to adhere
         to EB386. Edit RAM and EEPROM sections in PRM file to match these. */
#define ___INITRM      (*(volatile unsigned char *) 0x0010)
#define ___INITRG      (*(volatile unsigned char *) 0x0011)
#define ___INITEE      (*(volatile unsigned char *) 0x0012)
#endif

#if defined(_DO_FEED_COP_)
#define __FEED_COP_IN_HLI()  } __asm movb #0x55, _COP_RST_ADR; __asm movb #0xAA, _COP_RST_ADR; __asm {
#else
#define __FEED_COP_IN_HLI() /* do nothing */
#endif

#include "non_bank.sgm"

#pragma MESSAGE DISABLE C12053 /* Stack-pointer change not in debugging-information */
#pragma NO_FRAME
#pragma NO_ENTRY
#if !defined(__SMALL__)
#pragma NO_EXIT
#endif

/* The function _Startup must be called in order to initialize global variables and to call main */
/* You can adapt this function or call it from your startup code to implement a different startup */
/* functionality. */

/* You should also setup the needed IO registers as WINDEF (HC12A4 only) or the COP registers to run */
/* on hardware */

/* to set the reset vector several ways are possible : */
/* 1. define the function with "interrupt 0" as done below in the first case */
/* 2. add the following line to your prm file : VECTOR ADDRESS 0xfffe _Startup */
/* of course, even more posibilities exists */
/* the reset vector must be set so that the application has a defined entry point */

#if defined(__SET_RESET_VECTOR__)
__EXTERN_C void __interrupt 0 _Startup(void) {
#else
__EXTERN_C void _Startup(void) {
#endif
/*  purpose:    1)  initialize the stack
                2)  initialize the RAM, copy down init data etc (Init)
                3)  call main;
    parameters: NONE
    called from: _PRESTART-code generated by the Linker
                 or directly referenced by the reset vector */

   /* initialize the stack pointer */
   INIT_SP_FROM_STARTUP_DESC(); /*lint !e522 asm code */ /* HLI macro definition in hidef.h */

#if defined(_HCS12_SERIALMON)
   /* for Monitor based software remap the RAM & EEPROM to adhere
      to EB386. Edit RAM and EEPROM sections in PRM file to match these. */
   ___INITRG = 0x00;  /* lock registers block to 0x0000 */
   ___INITRM = 0x39;  /* lock Ram to end at 0x3FFF */
   ___INITEE = 0x09;  /* lock EEPROM block to end at 0x0fff */
#endif

   /* Here user defined code could be inserted, the stack could be used */
#if defined(_DO_DISABLE_COP_)
   _DISABLE_COP();
#endif

   /* Example : Set up WinDef Register to allow Paging */
#ifdef HC812A4 /* HC12 A4 derivative needs WINDEF to configure which pages are available */
#if  (__ENABLE_EPAGE__ != 0 ||  __ENABLE_DPAGE__ != 0 || __ENABLE_PPAGE__ != 0)
   WINDEF= __ENABLE_EPAGE__ | __ENABLE_DPAGE__  | __ENABLE_PPAGE__;
#endif
#endif


#ifndef __ONLY_INIT_SP

   Init(); /* zero out, copy down, call constructors */
#endif

   /* Here user defined code could be inserted, all global variables are initilized */
#if defined(_DO_ENABLE_COP_)
   _ENABLE_COP(1);
#endif

   /* call main() */
   main();
}


#ifndef __ONLY_INIT_SP
#if (!defined(FAR_DATA) || defined(__HCS12X__)) && (defined( __BANKED__) || defined(__LARGE__) || defined(__BANKED_COPY_DOWN))
static void __far Init(void)
#else
static void Init(void)
#endif
 {
/* purpose:     1) zero out RAM-areas where data is allocated   */
/*              2) copy initialization data from ROM to RAM     */
/*              3) call global constructors in C++              */
/*   called from: _Startup, LibInits                            */
   __asm {
ZeroOut:
#if defined(__HIWARE_OBJECT_FILE_FORMAT__) && defined(__LARGE__)
             LDX   _startupData.pZeroOut:1  ; in the large memory model in the HIWARE format, pZeroOut is a 24 bit pointer
#else
             LDX   _startupData.pZeroOut    ; *pZeroOut
#endif