boot_init.c

这是某个项目中使用的ARM7TDMI平台上ucos系统的bootloader

/****************************************************************************
**  Copyright  (c)  2004,  UTStarcom, Inc.
**          All Rights Reserved.
**
**  Subsystem  : Platform support
**  File       : boot_init.c
**  Created By : Sean Yang
**  Created On : 2005.01.21
**
**  Purpose:
**    initilize registers of CPU
**
****************************************************************************/

/****************************************************************************
* includes
****************************************************************************/

/***************************************************************************
* extern functions
***************************************************************************/

/***************************************************************************
* Defines and Typedefs
***************************************************************************/

typedef unsigned char 	U8;
typedef unsigned short 	U16;
typedef unsigned int  	U32;

#define REG_TIM_CNTL     0x007FF13F
#define REG_MEM_REMAP    0x007FF804

#define REG_CS_WAITSEL1	 0x007FF808
#define REG_CS_WAITSEL2	 0x007FF809

#define REG_PIO_SET      0x007FF811
#define REG_PIO_DATA     0x007FF820
#define REG_DIO1_CTL     0x007FF810
#define REG_DIO1_IO      0x007FF820

#define EXT_SRAM_BASE  	 0x00200000
#define EXT_SRAM_SIZE    0x001A0000	/* reserve Trace area 384K bytes */

#define BOOTLD_BASE  	 0x00002000
#define BOOTLD_SIZE      0x0001E000
#define RUNNING_BASE	 0x00300000

#define LED_ERR_2    3   /* ram check error */

/***************************************************************************
* Global and Local Data Definitions 
***************************************************************************/
void reset_watchdog(void)
{
 	U8 * regs;
 	U8 i;
 	
 	regs = (U8 *)REG_PIO_DATA;	/* output high level to PIO5 */
 	*regs = 0x20;

 	for (i=0; i<8;i++);

 	regs = (U8 *)REG_PIO_DATA;	/* output low level to PIO5 */
 	*regs = 0x00;
}

void boot_led_switch(U8 times)
{
    U32 loop_cnt1, loop_cnt2, loop_cnt3;
	unsigned char * led_ptr = (unsigned char *)0x007ff823;

    for (loop_cnt1 = 0; loop_cnt1 < times; loop_cnt1++)
    {
	    *led_ptr |= 0x02;	/* turn off */
        for (loop_cnt2 = 0; loop_cnt2 < 10; loop_cnt2++)
        {
            for(loop_cnt3 = 0; loop_cnt3 < 10000; loop_cnt3++) {}/* about 1.6s */
            reset_watchdog();
        }
    	
    	*led_ptr &= ~0x02; /* turn on */
        for (loop_cnt2 = 0; loop_cnt2 < 10; loop_cnt2++)
        {
            for(loop_cnt3 = 0; loop_cnt3 < 10000; loop_cnt3++) {}/* about 1.6s */
            reset_watchdog();
        }
    }
}

/****************************************************************************
**
**  FUNCTION NAME: lowlevel_init
**
**  Description:
**    This function performs very low level HW initialization
**
**  Argument       		 Type   									IO     Description
**  ------------- -------- -- ---------------------------------
**  vector						U32*		Input		vector table Address determinate in Relative addressing
**  internalRam				U32*		Input		Internal Address determinate in Relative addressing
**
**  Global Variables:
**	
**  Return Value: N/A
**						  
**   HISTORY (Recommended but Optional):
**
**    Programmer           Date	     Description of Revision
**    -------------------- ---------- ------------------------------
**    Sean Yang				2005.01.21 	Initial Writing
****************************************************************************/

void lowlevel_init(U32 * vector, U32 * internal_ram)
{
 	U32 i;
 	U8 * regs;

 	regs = (U8 *)REG_TIM_CNTL;	/* set timer control register */
 	*regs = 0x03;

 	regs = (U8 *)REG_MEM_REMAP;	/* before remap memory */
 	*regs = 0x30;
 	
 	/* set waiting phase of CS0(FLASH),CS1(SRAM),CS2(FPGA) */
 	
 	regs = (U8 *)REG_CS_WAITSEL1;
 	*regs = 0x12;
 	
 	regs = (U8 *)REG_CS_WAITSEL2;
 	*regs = 0x02;

	/* initialize WatchDog, enable */
	
 	regs = (U8 *)REG_PIO_SET;	/* set PIO5 to output */
 	*regs = 0x04;

 	regs = (U8 *)REG_PIO_DATA;	/* output low level to PIO5 */
 	*regs = 0x00;

 	regs = (U8 *)REG_DIO1_CTL;
 	*regs = 0x04;

 	regs = (U8 *)REG_PIO_DATA;
 	*regs = 0x00;

	/* Setup Exception Vectors in Internal RAM before Remap
	   Before Remap the internal RAM it's 0x00700000
	   After  Remap the internal RAM it's 0x00000000
		 Copy the ARM exception vectors and indirect table */

	for  (i = 0;i < 16; i++ )
	{
	   *internal_ram++ = *vector++;
	}

	/*Clear internal RAM, but this ram also used for STACK
	 when call this function, so can not clear the top 4 WORDs*/
	for (i = 16; i < 1000; i++) 
	{
		*internal_ram++ = 0;
	}
}

/****************************************************************************
**
**  FUNCTION NAME: copy_bootld
**
**  Description:
**   	copy boot loader to sram, and run it.
**
**  Argument       		 Type   									IO     Description
**  ------------- -------- -- ---------------------------------
**
**  Global Variables:
**	
**  Return Value: N/A
**						  
**   HISTORY (Recommended but Optional):
**
**    Programmer           Date	     Description of Revision
**    -------------------- ---------- ------------------------------
**    Sean Yang				2004.01.28 	Initial Writing
****************************************************************************/

void copy_bootld(void)
{
	U32 i;
	U32 * src;
	U32 * dest;
	unsigned char * cntl_ptr = (unsigned char *)0x007ff816;
	unsigned char * led_ptr = (unsigned char *)0x007ff823;

	*cntl_ptr |= 0x04; /* set to output */
	*led_ptr &= ~0x02;	/* turn on */

	/* test SRAM, from 0x00300000 to 0x003A0000, the other SRAM will be tested in boot loader 2 */

	for (i = 0; i < EXT_SRAM_SIZE / 4; i++) /* write 0x55, and read */
	{
		*(U32 *)(EXT_SRAM_BASE + i * 4) = 0x55555555;
		if (*(U32 *)(EXT_SRAM_BASE + i * 4) != 0x55555555)
		{
		    boot_led_switch(LED_ERR_2);
			while(1);	/* reset system */
	    }
		
		if ((i + 1) % 4096 == 0)	/* reset watchdog */
			reset_watchdog();
	}

	for (i = 0; i < EXT_SRAM_SIZE / 4; i++) /* write 0xAA, and read */
	{
		*(U32 *)(EXT_SRAM_BASE + i * 4) = 0xaaaaaaaa;
		if (*(U32 *)(EXT_SRAM_BASE + i * 4) != 0xaaaaaaaa)
		{
		    boot_led_switch(LED_ERR_2);
			while(1);	/* reset system */
	    }
		
		if ((i + 1) % 4096 == 0)	/* reset watchdog */
			reset_watchdog();
	}
	/* clear SRAM, from 0x00200000 to 0x003A0000 */

	for (i = 0; i < EXT_SRAM_SIZE / 4; i++)
	{
		*(U32 *)(EXT_SRAM_BASE + i * 4) = 0;
		
		if ((i + 1) % 4096 == 0)	/* reset watchdog */
			reset_watchdog();
	}

	/* copy boot loader to temp area in SRAM, then run it in SRAM to unzip version */
	
	dest = (U32 *)RUNNING_BASE;
	src = (U32 *)BOOTLD_BASE;

	for (i = 0; i < BOOTLD_SIZE / 4; i++)
	{
		*dest++ = *src++;
		
		if ((i + 1) % 4096 == 0)	/* reset watchdog */
			reset_watchdog();
	}
	
	*led_ptr |= 0x02;	/* turn off */
}