toaruos/core/system.c

#include <system.h>

/*
 * memcpy
 * Copy from source to destination. Assumes that
 * source and destination are not overlapping.
 */
void *
memcpy(
		void * restrict dest,
		const void * restrict src,
		size_t count
	  ) {
	size_t i;
	unsigned char *a = dest;
	const unsigned char *b = src;
	for ( i = 0; i < count; ++i ) {
		a[i] = b[i];
	}
	return dest;
}

int
strcmp(
		const char * a,
		const char * b
	  ) {
	uint32_t i = 0;
	while (1) {
		if (a[i] < b[i]) {
			return -1;
		} else if (a[i] > b[i]) {
			return 1;
		} else {
			if (a[i] == '\0') {
				return 0;
			}
			++i;
		}
	}
}

/*
 * memset
 * Set `count` bytes to `val`.
 */
void *
memset(
		void *b,
		int val,
		size_t count
	  ) {
	size_t i;
	unsigned char * dest = b;
	for ( i = 0; i < count; ++i ) {
		dest[i] = (unsigned char)val;
	}
	return b;
}

/*
 * memsetw
 * Set `count` shorts to `val`.
 */
unsigned short *
memsetw(
		unsigned short *dest,
		unsigned short val,
		int count
	) {
	int i;
	i = 0;
	for ( ; i < count; ++i ) {
		dest[i] = val;
	}
	return dest;
}

/*
 * strlen
 * Returns the length of a given `str`.
 */
int
strlen(
		const char *str
	  ) {
	int i = 0;
	while (str[i] != (char)0) {
		++i;
	}
	return i;
}

/*
 * inportb
 * Read from an I/O port.
 */
unsigned char
inportb(
		unsigned short _port
	   ) {
	unsigned char rv;
	__asm__ __volatile__ ("inb %1, %0" : "=a" (rv) : "dN" (_port));
	return rv;
}

/*
 * outportb
 * Write to an I/O port.
 */
void
outportb(
		unsigned short _port,
		unsigned char _data
		) {
	__asm__ __volatile__ ("outb %1, %0" : : "dN" (_port), "a" (_data));
}