sark_io.c File Reference

Simple character I/O library for Spinnaker. More...

#include <sark.h>
#include <stdarg.h>

Data Structures
struct	iobuf_t

Functions
static sdp_msg_t *	io_std_init (void)
	Initialises the IO_STD implementation.
static iobuf_t *	io_buf_init (void)
	Initialises a memory chunk for the IO_BUF implementation.
void	sark_io_buf_reset (void)
	Routine to reset the IOBUF for the core.
void	io_put_char (char *stream, uint c)
	Routine to put a character to an output stream.
void	io_printf (char *stream, char *f,...)
	A simple "printf" routine.
Format implementations
Routines to deal with the various printf formats. All end up calling io_put_char() to do the write of individual characters.
static void	io_put_str (char *stream, char *s, int d)
	Put a string possibly left-padding with spaces.
static void	io_put_int (char *stream, int n, uint d, uint pad)
	Put an integer (signed) in given field width, left-padding with spaces. Entire field is assumed to fit in 16 chars!.
static void	io_put_uint (char *stream, uint n, uint d, uint pad)
	Put an integer (unsigned) in given field width, left-padding with spaces. Entire field is assumed to fit in 16 chars!.
static void	io_put_zhex (char *stream, uint n, uint d)
	Put a hex number in exactly the number of characters specified. Truncates high digits if need be.
static void	io_put_hex (char *stream, uint n, uint d, uint pad)
	Put an integer in hex in given field width, left-padding with spaces. Entire field is assumed to fit in 16 chars!
static void	io_put_fixed (char *stream, uint n, uint d, uint a, uint pad, int neg)
	Format for 16.16 fixed point.
static void	io_put_sfixed (char *stream, int n, uint d, uint a, uint pad)
	Format for s16.15 fixed point.
static void	io_put_ufixed (char *stream, uint n, uint d, uint a, uint pad)
	Format for u16.16 fixed point.

Variables
static uint	sp_ptr
	Buffer pointer for 'sprintf'.
static uint	buf_ptr
	Buffer pointer for IO_BUF.
static sdp_msg_t *	io_msg
	Points to SDP buffer.
static iobuf_t *	io_buf
	Points to SDRAM buffer.
static const char	hex [] = "0123456789abcdef"
	Hexadecimal characters.

Detailed Description

Simple character I/O library for Spinnaker.

Copyright

© The University of Manchester - 2009-2019

Author

Steve Temple, APT Group, School of Computer Science. Fixed point formats by Paul Richmond (Univ. of Sheffield) and Dave Lester (APT Group)

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Data Structure Documentation

iobuf_t

struct iobuf_t

Struct containing information about each iobuf entry in the linked list of iobuf entries.

Data Fields
struct iobuf *	next
uint	unix_time
uint	time_ms
uint	ptr
uchar	buf[]

Function Documentation

io_std_init()

static sdp_msg_t * io_std_init ( void  )

static

Initialises the IO_STD implementation.

Returns

a pointer to the message buffer to use to send to host

io_buf_init()

static iobuf_t * io_buf_init ( void  )

static

Initialises a memory chunk for the IO_BUF implementation.

Returns

a pointer to the chunk

sark_io_buf_reset()

void sark_io_buf_reset

(

void

)

Routine to reset the IOBUF for the core.

Frees additional allocated IOBUF blocks in the system heap.

io_put_char()

void io_put_char	(	char *	stream,
		uint	c
	)

Routine to put a character to an output stream.

Has different behaviour for four possible streams:

• IO_STD: Streamed out to a tubotron instance via SDP.
• IO_BUF: Stored in a buffer in memory for later retrieval by host
• IO_NULL: Ignores the write
• "sprintf" strings: writes into the provided buffer.

For IO_STD and IO_BUF the character is placed in a holding buffer which is flushed on buffer-full or newline or NULL.

Parameters

stream	constant (IO_BUF, IO_STD, IO_NULL) or pointer to char array
c	a character

io_put_str()

static void io_put_str ( char *  stream, char *  s, int  d  )

static

Put a string possibly left-padding with spaces.

Parameters

[in]	stream	Where to write to
[in]	s	The string to write
[in]	d	The number of characters to write

Note

Always pads with spaces (where any padding is required)

io_put_int()

static void io_put_int ( char *  stream, int  n, uint  d, uint  pad  )

static

Put an integer (signed) in given field width, left-padding with spaces. Entire field is assumed to fit in 16 chars!.

Parameters

[in]	stream	Where to write to
[in]	n	The word to write
[in]	d	The number of digits to write
[in]	pad	The padding character to use

io_put_uint()

static void io_put_uint ( char *  stream, uint  n, uint  d, uint  pad  )

static

Put an integer (unsigned) in given field width, left-padding with spaces. Entire field is assumed to fit in 16 chars!.

Parameters

[in]	stream	Where to write to
[in]	n	The word to write
[in]	d	The number of digits to write
[in]	pad	The padding character to use

io_put_zhex()

static void io_put_zhex ( char *  stream, uint  n, uint  d  )

static

Put a hex number in exactly the number of characters specified. Truncates high digits if need be.

Parameters

[in]	stream	Where to write to
[in]	n	The word to write
[in]	d	The number of digits to write

io_put_hex()

static void io_put_hex ( char *  stream, uint  n, uint  d, uint  pad  )

static

Put an integer in hex in given field width, left-padding with spaces. Entire field is assumed to fit in 16 chars!

Parameters

[in]	stream	Where to write to
[in]	n	The word to write
[in]	d	The number of digits to write
[in]	pad	The padding character to use

io_put_fixed()

static void io_put_fixed ( char *  stream, uint  n, uint  d, uint  a, uint  pad, int  neg  )

static

Format for 16.16 fixed point.

Author

Paul Richmond

Dave Lester

Parameters

[in]	stream	Where to write to
[in]	n	unsigned accum, as unsigned integer
[in]	d	Field width
[in]	a	Precision
[in]	pad	Padding character
[in]	neg	True if a minus sign needs to be written

io_put_sfixed()

static void io_put_sfixed ( char *  stream, int  n, uint  d, uint  a, uint  pad  )

static

Format for s16.15 fixed point.

Delegates to io_put_fixed()

Parameters

[in]	stream	Where to write to
[in]	n	signed accum, as signed integer
[in]	d	Field width
[in]	a	Precision
[in]	pad	Padding character

io_put_ufixed()

static void io_put_ufixed ( char *  stream, uint  n, uint  d, uint  a, uint  pad  )

static

Format for u16.16 fixed point.

Delegates to io_put_fixed()

Parameters

[in]	stream	Where to write to
[in]	n	unsigned accum, as unsigned integer
[in]	d	Field width
[in]	a	Precision
[in]	pad	Padding character

io_printf()

void io_printf	(	char *	stream,
		char *	format,
			...
	)

A simple "printf" routine.

The first argument is a 'stream' which is either a constant (IO_BUF, IO_STD, IO_DBG, IO_NULL) or a pointer to a character array which will be filled in as in "sprintf". No checks for buffer overflow are made for this latter case! The range of formats is very limited to minimise code size. The maximum width for integer fields is 16.The maximum width for the 16.16 fixed point format is 25. Don't exceed these maxima!

The four constants provide 4 possible output streams for the output string. IO_STD will send the string as an SDP packet back to the host. IO_BUF will place the string in a buffer in SDRAM while IO_NULL will ignore the string. IO_DBG is not currently implemented.

Formats are:

• %c - character
• %s - string - can be eg %8s for right justification
• %d - signed integer (also %8d, %06d, etc)
• %u - signed integer (also %4u, %06u, etc)
• %x - integer in hex (also %4x, %08x, etc)
• %z - integer in hex, exactly N digits
• %n.mf - 16.16 fixed point with width n, precision m

Parameters

stream	constant (IO_BUF, IO_STD, IO_DBG, IO_NULL) or pointer to char array
format	a format string
...	arguments to be formatted