sbf_boot_code_5227x.s

来自「Freescale MCF5445evb 参考测试代码」· S 代码 · 共 67 行

/*
 * File:    sbf_boot_code.s
 * Purpose: Sample image that is bootable from SBF
 *
 * Notes:   
 *
 */

#ifdef _UNDERSCORE_
#define __CORE_SRAM              ___CORE_SRAM
#define __CORE_SRAM_SIZE         ___CORE_SRAM_SIZE
#endif
 
    .extern __CORE_SRAM
    .extern __CORE_SRAM_SIZE
    .global _asm_startmeup

    .text

/********************************************************************
 *
 * Exception Vector Table
 */
VECTOR_TABLE:
_VECTOR_TABLE:
INITSP:     .long   __CORE_SRAM + 0x1000    /* Initial SP           */
INITPC:     .long   asm_startmeup           /* Initial PC           */

/********************************************************************
 * This is the main entry point upon hard reset.
 */
asm_startmeup:
_asm_startmeup:

	nop
    
    /* Initialize 32KByte SRAM */
    move.l  #__CORE_SRAM,d0
    add.l   #0x221,d0
    movec   D0,RAMBAR1
    
    move.b	#0x0F,d0
    move.b	d0,0xFC0A4013

loop1:
    nop
    move.l  #0x00200000,d0
    move.b  #0x0F,d1
    move.b  d1,0xFC0A4007
wait1:
    nop
    subq.l  #1,d0
    bne     wait1
loop2:    
    move.l  #0x00200000,d0
    move.b  #0x00,d1
    move.b  d1,0xFC0A4007
wait2:
    nop
    subq.l  #1,d0
    bne     wait2

    bra     loop1
    
/********************************************************************/
.end