mcf532x_lo.s

motorola 针对coldfire 5275 评估板的Dbug bootloader源程序

/*
 * File:	mcf532x_lo.s
 * Purpose:	Lowest level routines for mcf532x.
 *
 * Notes:	
 *
 */

#ifdef _UNDERSCORE_
#define __CORE_SRAM         ___CORE_SRAM
#define __CORE_SRAM_SIZE    ___CORE_SRAM_SIZE
#define __SP_INIT           ___SP_INIT
#define sysinit        		_sysinit
#define main                _main
#define asm_set_ipl         _asm_set_ipl
#endif
 
    .extern __CORE_SRAM
    .extern __CORE_SRAM_SIZE
    .extern __SP_INIT
    .extern sysinit
    .extern main
    .extern asm_set_ipl
 
    .global asm_startmeup
    .global _asm_startmeup
    .global cpu_cache_flush
    .global _cpu_cache_flush

    .text

/********************************************************************
 * This is the main entry point upon hard reset.
 */
asm_startmeup:
_asm_startmeup:
    
    
    /* Initialize RAMBAR1: locate SRAM, enable back door, and validate it */
    move.l  #__CORE_SRAM,d0
    add.l   #0x221,d0
   .long   0x4e7b0C05      /* movec d0,RAMBAR1 */

    /* Point Stack Pointer into SRAM temporarily */
    move.l  #__CORE_SRAM,d0
    add.l   #__CORE_SRAM_SIZE,d0
    move.l  d0,sp
    
    /* Initialize mcf5208 periphs, etc */
    jsr     sysinit

    /* Relocate Stack Pointer */ 
    move.l  #__SP_INIT,SP
    
	/* Jump to the main process */
#ifdef __GNUC__	
	jsr		dbug_main
#else
	jsr		main
#endif	
	
	bra		.
	nop
	nop
	halt

/********************************************************************
 * The MCF5208 cache can be configured as instruction, data or split.
 * Invalidate the entire cache.
 */
cpu_cache_flush:
_cpu_cache_flush:
    nop                     /* sync */
    move.l  #0x01000000,d0  /* Invalidate the I-Cache */
    movec   d0,cacr
    rts

    .end