Re: Stdio redirection?

[Aklilu Noah <naklilu at gpu dot srv dot ualberta dot ca>]

Actually you write a set of support functions of which
two are read and write (low level i/o functions).  These
provide the ability to read and write characters to whatever
i/o device you are using e.g. a UART.

The web documentation on newlib should provide a list of support
functions that are required.  I believe printf also requires
a malloc function (for allocating a buffer).

Noah.

On Mon, 2 Oct 2000, Russ.Shaw wrote:

> Date: Mon, 02 Oct 2000 15:05:55 +1000
> From: Russ.Shaw <russell@webaxs.net>
> To: newlib@sources.redhat.com, crossgcc@sourceware.cygnus.com
> Subject: Stdio redirection?
> 
> Hi all,
> 
> I'm using gcc-2.95.2 on a gnu/linux system, configured as a
> cross-compiler for the hitachi h8300-hms.
> 
> I got a cygnus CD with the hitachi board i bought, but it only
> works with windoze, and the manuals don't cover what i need...
> 
> In <stdio.h> (inluded here), how do i get the printf() functions
> to use my own putch() and getch() functions for the serial ports?
> 
> 
> 
> /*
>  * Copyright (c) 1990 The Regents of the University of California.
>  * All rights reserved.
>  *
>  * Redistribution and use in source and binary forms are permitted
>  * provided that the above copyright notice and this paragraph are
>  * duplicated in all such forms and that any documentation,
>  * advertising materials, and other materials related to such
>  * distribution and use acknowledge that the software was developed
>  * by the University of California, Berkeley.  The name of the
>  * University may not be used to endorse or promote products derived
>  * from this software without specific prior written permission.
>  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
>  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
>  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
>  *
>  *	@(#)stdio.h	5.3 (Berkeley) 3/15/86
>  */
> 
> /*
>  * NB: to fit things in six character monocase externals, the
>  * stdio code uses the prefix `__s' for stdio objects, typically
>  * followed by a three-character attempt at a mnemonic.
>  */
> 
> #ifndef _STDIO_H_
> #ifdef __cplusplus
> extern "C" {
> #endif
> #define	_STDIO_H_
> 
> #include "_ansi.h"
> 
> #define	_FSTDIO			/* ``function stdio'' */
> 
> #define __need_size_t
> #include <stddef.h>
> 
> #define __need___va_list
> #include <stdarg.h>
> 
> /*
>  * <sys/reent.h> defines __sFILE, _fpos_t.
>  * They must be defined there because struct _reent needs them (and we don't
>  * want reent.h to include this file.
>  */
> 
> #include <sys/reent.h>
> 
> typedef _fpos_t fpos_t;
> 
> typedef struct __sFILE FILE;
> 
> #define	__SLBF	0x0001		/* line buffered */
> #define	__SNBF	0x0002		/* unbuffered */
> #define	__SRD	0x0004		/* OK to read */
> #define	__SWR	0x0008		/* OK to write */
> 	/* RD and WR are never simultaneously asserted */
> #define	__SRW	0x0010		/* open for reading & writing */
> #define	__SEOF	0x0020		/* found EOF */
> #define	__SERR	0x0040		/* found error */
> #define	__SMBF	0x0080		/* _buf is from malloc */
> #define	__SAPP	0x0100		/* fdopen()ed in append mode - so must  write to end */
> #define	__SSTR	0x0200		/* this is an sprintf/snprintf string */
> #define	__SOPT	0x0400		/* do fseek() optimisation */
> #define	__SNPT	0x0800		/* do not do fseek() optimisation */
> #define	__SOFF	0x1000		/* set iff _offset is in fact correct */
> #define	__SMOD	0x2000		/* true => fgetline modified _p text */
> #if defined(__CYGWIN__) || defined(__CYGWIN__)
> #define __SCLE        0x4000          /* convert line endings CR/LF <-> NL */
> #endif
> 
> /*
>  * The following three definitions are for ANSI C, which took them
>  * from System V, which stupidly took internal interface macros and
>  * made them official arguments to setvbuf(), without renaming them.
>  * Hence, these ugly _IOxxx names are *supposed* to appear in user code.
>  *
>  * Although these happen to match their counterparts above, the
>  * implementation does not rely on that (so these could be renumbered).
>  */
> #define	_IOFBF	0		/* setvbuf should set fully buffered */
> #define	_IOLBF	1		/* setvbuf should set line buffered */
> #define	_IONBF	2		/* setvbuf should set unbuffered */
> 
> #ifndef NULL
> #define	NULL	0
> #endif
> 
> #define	BUFSIZ	1024
> #define	EOF	(-1)
> 
> #define	FOPEN_MAX	20	/* must be <= OPEN_MAX <sys/syslimits.h> */
> #define	FILENAME_MAX	1024	/* must be <= PATH_MAX <sys/syslimits.h> */
> #define	L_tmpnam	1024	/* XXX must be == PATH_MAX */
> #ifndef __STRICT_ANSI__
> #define P_tmpdir        "/tmp"
> #endif
> 
> #ifndef SEEK_SET
> #define	SEEK_SET	0	/* set file offset to offset */
> #endif
> #ifndef SEEK_CUR
> #define	SEEK_CUR	1	/* set file offset to current plus offset */
> #endif
> #ifndef SEEK_END
> #define	SEEK_END	2	/* set file offset to EOF plus offset */
> #endif
> 
> #define	TMP_MAX		26
> 
> #define	stdin	(_impure_ptr->_stdin)
> #define	stdout	(_impure_ptr->_stdout)
> #define	stderr	(_impure_ptr->_stderr)
> 
> #define _stdin_r(x)	((x)->_stdin)
> #define _stdout_r(x)	((x)->_stdout)
> #define _stderr_r(x)	((x)->_stderr)
> 
> /*
>  * Functions defined in ANSI C standard.
>  */
> 
> #ifdef __GNUC__
> #define __VALIST __gnuc_va_list
> #else
> #define __VALIST char*
> #endif
> 
> #ifndef _REENT_ONLY
> int	_EXFUN(remove, (const char *));
> int	_EXFUN(rename, (const char *, const char *));
> #endif
> char *	_EXFUN(tempnam, (const char *, const char *));
> FILE *	_EXFUN(tmpfile, (void));
> char *	_EXFUN(tmpnam, (char *));
> int	_EXFUN(fclose, (FILE *));
> int	_EXFUN(fflush, (FILE *));
> FILE *	_EXFUN(freopen, (const char *, const char *, FILE *));
> void	_EXFUN(setbuf, (FILE *, char *));
> int	_EXFUN(setvbuf, (FILE *, char *, int, size_t));
> int	_EXFUN(fprintf, (FILE *, const char *, ...));
> int	_EXFUN(fscanf, (FILE *, const char *, ...));
> int	_EXFUN(printf, (const char *, ...));
> int	_EXFUN(scanf, (const char *, ...));
> int	_EXFUN(sscanf, (const char *, const char *, ...));
> int	_EXFUN(vfprintf, (FILE *, const char *, __VALIST));
> int	_EXFUN(vprintf, (const char *, __VALIST));
> int	_EXFUN(vsprintf, (char *, const char *, __VALIST));
> int	_EXFUN(vsnprintf, (char *, size_t, const char *, __VALIST));
> int	_EXFUN(fgetc, (FILE *));
> char *  _EXFUN(fgets, (char *, int, FILE *));
> int	_EXFUN(fputc, (int, FILE *));
> int	_EXFUN(fputs, (const char *, FILE *));
> int	_EXFUN(getc, (FILE *));
> int	_EXFUN(getchar, (void));
> char *  _EXFUN(gets, (char *));
> int	_EXFUN(putc, (int, FILE *));
> int	_EXFUN(putchar, (int));
> int	_EXFUN(puts, (const char *));
> int	_EXFUN(ungetc, (int, FILE *));
> size_t	_EXFUN(fread, (_PTR, size_t _size, size_t _n, FILE *));
> size_t	_EXFUN(fwrite, (const _PTR , size_t _size, size_t _n, FILE *));
> int	_EXFUN(fgetpos, (FILE *, fpos_t *));
> int	_EXFUN(fseek, (FILE *, long, int));
> int	_EXFUN(fsetpos, (FILE *, const fpos_t *));
> long	_EXFUN(ftell, ( FILE *));
> void	_EXFUN(rewind, (FILE *));
> void	_EXFUN(clearerr, (FILE *));
> int	_EXFUN(feof, (FILE *));
> int	_EXFUN(ferror, (FILE *));
> void    _EXFUN(perror, (const char *));
> #ifndef _REENT_ONLY
> FILE *	_EXFUN(fopen, (const char *_name, const char *_type));
> int	_EXFUN(sprintf, (char *, const char *, ...));
> int	_EXFUN(snprintf, (char *, size_t, const char *, ...));
> #endif
> #ifndef __STRICT_ANSI__
> int	_EXFUN(vfiprintf, (FILE *, const char *, __VALIST));
> int	_EXFUN(iprintf, (const char *, ...));
> int	_EXFUN(fiprintf, (FILE *, const char *, ...));
> int	_EXFUN(siprintf, (char *, const char *, ...));
> #endif
> 
> /*
>  * Routines in POSIX 1003.1.
>  */
> 
> #ifndef __STRICT_ANSI__
> #ifndef _REENT_ONLY
> FILE *	_EXFUN(fdopen, (int, const char *));
> #endif
> int	_EXFUN(fileno, (FILE *));
> int	_EXFUN(getw, (FILE *));
> int	_EXFUN(pclose, (FILE *));
> FILE *  _EXFUN(popen, (const char *, const char *));
> int	_EXFUN(putw, (int, FILE *));
> void    _EXFUN(setbuffer, (FILE *, char *, int));
> int	_EXFUN(setlinebuf, (FILE *));
> #endif
> 
> /*
>  * Recursive versions of the above.
>  */
> 
> FILE *	_EXFUN(_fdopen_r, (struct _reent *, int, const char *));
> FILE *	_EXFUN(_fopen_r, (struct _reent *, const char *, const char *));
> int	_EXFUN(_getchar_r, (struct _reent *));
> char *	_EXFUN(_gets_r, (struct _reent *, char *));
> int	_EXFUN(_iprintf_r, (struct _reent *, const char *, ...));
> int	_EXFUN(_mkstemp_r, (struct _reent *, char *));
> char *	_EXFUN(_mktemp_r, (struct _reent *, char *));
> void	_EXFUN(_perror_r, (struct _reent *, const char *));
> int	_EXFUN(_printf_r, (struct _reent *, const char *, ...));
> int	_EXFUN(_putchar_r, (struct _reent *, int));
> int	_EXFUN(_puts_r, (struct _reent *, const char *));
> int	_EXFUN(_remove_r, (struct _reent *, const char *));
> int	_EXFUN(_rename_r, (struct _reent *,
> 			   const char *_old, const char *_new));
> int	_EXFUN(_scanf_r, (struct _reent *, const char *, ...));
> int	_EXFUN(_sprintf_r, (struct _reent *, char *, const char *, ...));
> int	_EXFUN(_snprintf_r, (struct _reent *, char *, size_t, const char *, ...));
> char *	_EXFUN(_tempnam_r, (struct _reent *, const char *, const char *));
> FILE *	_EXFUN(_tmpfile_r, (struct _reent *));
> char *	_EXFUN(_tmpnam_r, (struct _reent *, char *));
> int	_EXFUN(_vfprintf_r, (struct _reent *, FILE *, const char *, __VALIST));
> int	_EXFUN(_vprintf_r, (struct _reent *, const char *, __VALIST));
> int	_EXFUN(_vsprintf_r, (struct _reent *, char *, const char *, __VALIST));
> int	_EXFUN(_vsnprintf_r, (struct _reent *, char *, size_t, const char *, __VALIST));
> 
> /*
>  * Routines internal to the implementation.
>  */
> 
> int	_EXFUN(__srget, (FILE *));
> int	_EXFUN(__swbuf, (int, FILE *));
> 
> /*
>  * Stdio function-access interface.
>  */
> 
> #ifndef __STRICT_ANSI__
> FILE	*_EXFUN(funopen,(const _PTR _cookie,
> 		int (*readfn)(_PTR _cookie, char *_buf, int _n),
> 		int (*writefn)(_PTR _cookie, const char *_buf, int _n),
> 		fpos_t (*seekfn)(_PTR _cookie, fpos_t _off, int _whence),
> 		int (*closefn)(_PTR _cookie)));
> 
> #define	fropen(cookie, fn) funopen(cookie, fn, (int (*)())0, (fpos_t (*)())0, (int (*)())0)
> #define	fwopen(cookie, fn) funopen(cookie, (int (*)())0, fn, (fpos_t (*)())0, (int (*)())0)
> #endif
> 
> /*
>  * The __sfoo macros are here so that we can 
>  * define function versions in the C library.
>  */
> #define       __sgetc_raw(p) (--(p)->_r < 0 ? __srget(p) : (int)(*(p)->_p++))
> 
> #ifdef __SCLE
> static __inline__ int __sgetc(FILE *__p)
>   {
>     int __c = __sgetc_raw(__p);
>     if ((__p->_flags & __SCLE) && (__c == '\r'))
>       {
>       int __c2 = __sgetc_raw(__p);
>       if (__c2 == '\n')
>         __c = __c2;
>       else
>         ungetc(__c2, __p);
>       }
>     return __c;
>   }
> #else
> #define __sgetc(p) __sgetc_raw(p)
> #endif
> 
> #ifdef _never /* __GNUC__ */
> /* If this inline is actually used, then systems using coff debugging
>    info get hopelessly confused.  21sept93 rich@cygnus.com.  */
> static __inline int __sputc(int _c, FILE *_p) {
> 	if (--_p->_w >= 0 || (_p->_w >= _p->_lbfsize && (char)_c != '\n'))
> 		return (*_p->_p++ = _c);
> 	else
> 		return (__swbuf(_c, _p));
> }
> #else
> /*
>  * This has been tuned to generate reasonable code on the vax using pcc
>  */
> #define       __sputc_raw(c, p) \
> 	(--(p)->_w < 0 ? \
> 		(p)->_w >= (p)->_lbfsize ? \
> 			(*(p)->_p = (c)), *(p)->_p != '\n' ? \
> 				(int)*(p)->_p++ : \
> 				__swbuf('\n', p) : \
> 			__swbuf((int)(c), p) : \
> 		(*(p)->_p = (c), (int)*(p)->_p++))
> #ifdef __SCLE
> #define __sputc(c, p) \
>         ((((p)->_flags & __SCLE) && ((c) == '\n')) \
>           ? __sputc_raw('\r', (p)) : 0 , \
>         __sputc_raw((c), (p)))
> #else
> #define __sputc(c, p) __sputc_raw(c, p)
> #endif
> #endif
> 
> #define	__sfeof(p)	(((p)->_flags & __SEOF) != 0)
> #define	__sferror(p)	(((p)->_flags & __SERR) != 0)
> #define	__sclearerr(p)	((void)((p)->_flags &= ~(__SERR|__SEOF)))
> #define	__sfileno(p)	((p)->_file)
> 
> #define	feof(p)		__sfeof(p)
> #define	ferror(p)	__sferror(p)
> #define	clearerr(p)	__sclearerr(p)
> 
> #if 0 /*ndef __STRICT_ANSI__ - FIXME: must initialize stdio first, use fn */
> #define	fileno(p)	__sfileno(p)
> #endif
> 
> #ifndef __CYGWIN__
> #ifndef lint
> #define	getc(fp)	__sgetc(fp)
> #define putc(x, fp)	__sputc(x, fp)
> #endif /* lint */
> #endif /* __CYGWIN__ */
> 
> #define	getchar()	getc(stdin)
> #define	putchar(x)	putc(x, stdout)
> 
> #ifndef __STRICT_ANSI__
> /* fast always-buffered version, true iff error */
> #define	fast_putc(x,p) (--(p)->_w < 0 ? \
> 	__swbuf((int)(x), p) == EOF : (*(p)->_p = (x), (p)->_p++, 0))
> 
> #define	L_cuserid	9		/* posix says it goes in stdio.h :( */
> #ifdef __CYGWIN__
> #define L_ctermid       16
> #endif
> #endif
> 
> #ifdef __cplusplus
> }
> #endif
> #endif /* _STDIO_H_ */
> 
> 
> 
> -- 
> *******************************************
> *   Russell Shaw, B.Eng, M.Eng(Research)  *
> *      email: russell@webaxs.net          *
> *      Victoria, Australia                *
> *******************************************
> 
> ------
> Want more information?  See the CrossGCC FAQ, http://www.objsw.com/CrossGCC/
> Want to unsubscribe? Send a note to crossgcc-unsubscribe@sourceware.cygnus.com
> 

Noah Aklilu
aklilu@nyquist.ee.ualberta.ca
http://www.ee.ualberta.ca/~aklilu/
"Integrity is something you do when no one is looking"



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