print.c

spi_boot_example.tar.gz可以为大家在使用 Cirrus logic的ARM9芯片是提供帮助

/*==================================================================
 *
 *  This file is part of a small Nand flash bootloader designed to
 *  be loaded via EP93xx SPI boot.
 *
 *  Copyright Cirrus Logic Corporation, 2007.  All rights reserved
 *
 ==================================================================*/

#include <io.h>
#include <boot.h>

#define BDIV(baud) (((SYSTEM_CLOCK / 16)/(baud))-1)

void uart_setup(void)
{
    u32 tmp;

    //run at UART0 on extclk rather than extclk/2
    tmp = IN32(PWRCNT);
    tmp |= (1<<29);
    OUT32(tmp, PWRCNT);
    
//enable uart0
    OUT32(0xaa, SWLOCK);
    tmp=IN32(DEVCFG);
    tmp |= SYSCON_DEVCFG_U0EN;
    OUT32(0xaa, SWLOCK);
    OUT32(tmp, DEVCFG);

//uart0
    OUT32( BDIV(BOOT_BAUDRATE),UART0LINCTRLLOW );
    OUT32( 0,UART0LINCTRLMID );
    //8n1, tx fifo on
    OUT32( ((3<<5) | (1<<4)), UART0LINCTRLHIGH );
    //enable uart0
    OUT32( 1, UART0CTRL);
}



int putchar(int c)
{
    // while tx fifo full
    while( (IN32(UART0FLAG)) & (1<<5) )
    {
    }
    OUT32( c, UART0DR );

    if(c=='\n')
    {
	c='\r';
        // while tx fifo full
	while( (IN32(UART0FLAG)) & (1<<5) )
	{
	}
	OUT32( c, UART0DR );
    }

    // while UART is busy
    while( (IN32(UART0FLAG)) & (1<<3) )
    {
    }
    
    return 0;
}


int puts(const char *s)
{    
    while(*s)
    {
	putchar(*s++);
    }
    
    putchar('\n');
    return 0;
}


void puthex(u32 val)
{
    char hextab[]={"0123456789ABCDEF"};
    int i;
    
    for(i=28; i>=0; i-=4)
    {
	putchar(   hextab[ ((val >> i) & 0xf) ] );
    }
}