main.c

lpc2294 Bootloader Linux嵌入开发

/******************************************************************************/
/*                                                                            */
/*  main.C:  A test loader for Philips                                       */
/*                                                                            */
/******************************************************************************/


#include "lpc2294.h"        
       
#define	USRRxData      	(1 << 0)
#define	USRTxHoldEmpty 	(1 << 6)
#define GET_CHAR(p)	p
#define PUT_CHAR(p,c)  	(p= (unsigned )(c))
#define TX_READY(s)    	((s) & USRTxHoldEmpty)
#define RX_DATA(s)     	((s) & USRRxData)

#define COM0_USER	(0)
#define COM1_DEBUG	(1)

extern void loadkernel(void);

void init_serial(void)  {               /* Initialize Serial Interface       */
  U0LCR = 0x83;					/*8 bit char length;enable access to Divisor Latches */
  U0DLL = 65;			/*FOSC=10M, notusePLL,PCLK=2.5M,bitrate = PCLK / (16*U0DLL)*/
  U0LCR = 0x03;			/*8 bit char length;disable access to Divisor Latches*/
  U0IER = 0x00000007;		/*Enable RDA,THRE,RX line status  interrupts*/
  U0FCR = 0x00000081;		/*Enable FIFO*/
}

void serial_print(char *s)
{
	while ( *s != 0 ) {
		while ( TX_READY(U0LSR)==0);
		PUT_CHAR(U0DLL,*s++);
	}	
}		
int main(void)
{
    init_serial();	
    serial_print("\r\n**   Bootloader start   **\r\n");   
    loadkernel();
    return 0;
    
}