toaruos/core/system.c
2011-01-29 14:12:00 -06:00

119 lines
1.5 KiB
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));
}