LIBC tiny subset

The rflpc library implement a very small subset of the libc. More...

Functions
int	printf (const char *format,...)
	Formated output function. More...
void	rflpc_printf_set_putchar (int(*putchar_func)(int c))
	Sets the internal function pointer that is used by printf to output a character. More...
void *	memcpy (void *dest, const void *src, size_t n)
	Copies memory from one buffer to another. More...
void *	memset (void *dest, int c, size_t n)
	Fills the first n bytes of the memory area pointed to by dest with the constant byte c. More...
void	srand (unsigned int seed)
	Sets the seed used by rand() to generate the pseudo-random sequence. More...
int	rand (void)
	Returns a pseudo-random integer in the range of 0 to RAND_MAX. More...
int	rand_r (unsigned int *seed)
	Returns a pseudo-random integer in the range of 0 to RAND_MAX. More...
#define	RAND_MAX   2147483647
	The maximum value of a random number. More...

Detailed Description

The rflpc library implement a very small subset of the libc.

Macro Definition Documentation

#define RAND_MAX   2147483647

The maximum value of a random number.

The rand function generate number in [0, RAND_MAX] range.

Definition at line 41 of file rand.h.

Function Documentation

void* memcpy	(	void *	dest,
		const void *	src,
		size_t	n
	)

Copies memory from one buffer to another.

Note

if the src and dest are aligned on 4 bytes, copy is done by 4 bytes block, so it should be faster if the given pointers are aligned on a 4 byte boundary

Warning

dest and src should not overlap.

Parameters

[out]	dest	destination buffer
[in]	src	source buffer
[in]	n	number of bytes to copy

Returns

void* memset	(	void *	dest,
		int	c,
		size_t	n
	)

Fills the first n bytes of the memory area pointed to by dest with the constant byte c.

Note

if the src and dest are aligned on 4 bytes, memset is done by 4 bytes block, so it should be faster if the given pointers are aligned on a 4 byte boundary

Parameters

[out]	dest	destination buffer
[in]	c	value to set
[in]	n	number of bytes to copy

Returns

int printf	(	const char *	format,
			...
	)

Formated output function.

This function is similar to stdio's printf. However, it only handles:

• %d
• %x/X (%0?X can also be used, where ? is a digit [1-9])
• %p
• %c
• %s

Note

If another format char is used, int is assumed to skip argument, but nothing is printed unless RFLPC_VERBOSE_PRINTF is defined when compiling lib. If RFLPC_CONFIG_ENABLE_ATOMIC_PRINTF is defined, interrupts are disabled when entering printf and enabled before exiting

Warning

This function uses a function pointer to output each character. By default, it uses a function which eventually call rflpc_uart_putchar with RFLPC_UART0. If you want to use your own putchar function, you have to call rflpc_printf_set_putchar to set the function pointer.

Parameters

[in]

format

The format string. Prefer to use constant string instead of user supplied string to be sure that some escape characters are not put for wrong purpose.

int rand

(

void

)

Returns a pseudo-random integer in the range of 0 to RAND_MAX.

Warning

this function is not reentrant!

int rand_r

(

unsigned int *

seed

)

Returns a pseudo-random integer in the range of 0 to RAND_MAX.

Note

This function is reentrant as it uses a user defined pointer for its seed.

Parameters

seed	pointer to the current value of the seed.

void rflpc_printf_set_putchar

(

int(*)(int c)

putchar_func

)

Sets the internal function pointer that is used by printf to output a character.

By default, it uses a function that call rflpc_uart_putchar with RFLPC_UART0.

Parameters

[in]

putchar_func

a pointer to a function that takes a character to put and returns it.

void srand

(

unsigned int

seed

)

Sets the seed used by rand() to generate the pseudo-random sequence.

Parameters

seed	the seed to use.