retarget.c

三星2443芯片

/*
** Copyright (C) ARM Limited, 2004. All rights reserved.
*/

/*
** This file contains re-implementations of functions whose
** C library implementations rely on semihosting.
** I/O is targeted to the Versatile serial port A.  
*/

#include "system.h"

#if !SEMIHOSTING

/*
** Importing __use_no_semihosting_swi ensures that our image doesn't link
** with any C Library code that makes direct use of semihosting.
**
*/

#pragma import(__use_no_semihosting_swi)

/*
** Retargeted I/O
** ==============
** The following C library functions make use of semihosting
** to read or write characters to the debugger console: fputc(),
** fgetc(), and _ttywrch().  They must be retargeted to write to
** the Versatile AP UART.  __backspace() must also be retargeted
** with this layer to enable scanf().  See the Compiler and
** Libraries Guide.
*/

/*
** These must be defined to avoid linking in stdio.o from the
** C Library
*/
struct __FILE { int handle;   /* Add whatever you need here */};
FILE __stdout;
FILE __stdin;

/*
** __backspace must return the last char read to the stream
** fgetc() needs to keep a record of whether __backspace was
** called directly before it
*/
int last_char_read;
int backspace_called;

int fputc(int ch, FILE *f)
{
    Uart_putc(ch);

    return ch;
}

int fgetc(FILE *f)
{
    unsigned char tempch;

    /* if we just backspaced, then return the backspaced character */
    /* otherwise output the next character in the stream */
    if (backspace_called == TRUE)
    {
      backspace_called = FALSE;
      return last_char_read;
    }

    tempch = Uart_getc();
    Uart_putc(tempch);
    
	switch(tempch){
	case 0xd	: 	tempch=0xa; 
					break;
	case '\b'	:	Uart_putc(' ');
					Uart_putc('\b');
					break;
	}
    
    last_char_read = (int)tempch;       /* backspace must return this value */
    return tempch;
}

void _ttywrch(int ch)
{
    Uart_putc(ch);
}

/*
** The effect of __backspace() should be to return the last character
** read from the stream, such that a subsequent fgetc() will
** return the same character again.
*/

int __backspace(FILE *f)
{
    backspace_called = TRUE;
    return 1;
}

/* END of Retargeted I/O */

/*
** Exception Signaling and Handling
** ================================
** The C library implementations of ferror() uses semihosting directly
** and must therefore be retargeted.  This is a minimal reimplementation.
** _sys_exit() is called after the user's main() function has exited.  The C library
** implementation uses semihosting to report to the debugger that the application has
** finished executing.
*/

int ferror(FILE *f)
{
    return EOF;
}

void _sys_exit(int return_code)
{
    while(1);
}

#endif