serial.c

linux下的jtag调试软件

#include <pxa250regs.S>
#include <stdarg.h>
#include "serial.h"

void serial_send_byte(int byte)
{
	volatile int * const lsr= (volatile int *)(FFUART_BASE+UART_LSR);
	volatile int * const thr= (volatile int *)(FFUART_BASE+UART_THR);

	while (((*lsr) & SIO_LSR_THRE) == 0) ;

	*thr = byte;
}

int printf(const char *format, ...)
{
	va_list ap;
	char c;

	va_start(ap, format);
	while (1)
	{
		c=*format;
		switch (c)
		{
			// end of string
			case 0:
			{
				goto stopPrintf;
			}
			break;

			// special char
			case '%':
			{
				c=*(++format);
				switch (c)
				{
					// end of string
					case 0:
					{
						goto stopPrintf;
					}
					break;

					// display %
					case '%':
					{
						serial_send_byte('%');
					}
					break;

					// char
					case 'c':
					{
						char typeC=va_arg(ap, int);
						serial_send_byte(typeC);
					}
					break;

					// string
					case 's':
					{
						char *typeCP=va_arg(ap, char *);
						if (typeCP)
						{
							while (*typeCP)
							{
								serial_send_byte(*typeCP);
								typeCP++;
							}
						}
						else
						{
							serial_send_byte('n');
							serial_send_byte('u');
							serial_send_byte('l');
							serial_send_byte('l');
						}
					}
					break;

					// hexadecimal unsigned int
					case 'x':
					case 'X':
					{
						int i, v;
						unsigned int typeUI=va_arg(ap, unsigned int);
						char baseChar;
						if (c=='x')
							baseChar='a';
						else
							baseChar='A';
						for (i=28; i>=0; i-=4)
						{
							v=(typeUI>>i)&0xF;
							serial_send_byte(v < 10 ? ('0'+v) : (baseChar+(v-10)));
						}
					}
					break;

					// binary
					case 'b':
					{
						int i, v;
						unsigned int typeB=va_arg(ap, unsigned int);
						for (i=31; i>=0; i--)
						{
							v=(typeB>>i)&0x1;
							serial_send_byte(v == 1 ? '1' : '0');
						}
					}
					break;

					// decimal unsigned int
					case 'u':
					{
						unsigned int typeUI=va_arg(ap, unsigned int);
						unsigned int div;
						int hasPut=0;
						for (div=1000000000; div>0; div/=10)
						{
							unsigned int aff=typeUI/div;
							typeUI%=div;

							if ((aff!=0) || (hasPut))
							{
								hasPut=1;
								serial_send_byte('0'+aff);
							}
						}
						if (!hasPut)
							serial_send_byte('0');
					}
					break;

					// decimal signed int
					case 'd':
					{
						int typeI=va_arg(ap, int);
						unsigned int vAbs;
						unsigned int div;
						int hasPut=0;
						if (typeI<0)
						{
							vAbs=(unsigned)(-typeI);
							serial_send_byte('-');
						}
						else
						{
							vAbs=(unsigned)typeI;
						}
						for (div=1000000000; div>0; div/=10)
						{
							unsigned int aff=vAbs/div;
							vAbs%=div;

							if ((aff!=0) || (hasPut))
							{
								hasPut=1;
								serial_send_byte('0'+aff);
							}
						}
						if (!hasPut)
							serial_send_byte('0');
					}
					break;

					// display char if not handled
					default:
					{
						serial_send_byte(c);
					}
					break;
				}
			}
			break;

			// other
			default:
			{
				serial_send_byte(c);
			}
			break;
		}
		format++;
	}

// clean stack and return
stopPrintf:
	va_end(ap);

	// TODO : return number of printed character
	return 0;
}