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#include "strings.h"
void uint32_to_dec(uint32_t number, char buf[10])
{
for (int i = 0; i < 10; i++)
{
buf[10 - 1 - i] = '0' + (number % 10);
number /= 10;
}
}
void uint32_to_hex(uint32_t number, char buf[8])
{
for (int i = 0; i < 8; i++)
{
unsigned char quadbit = (number >> ((8 - i - 1) * 4)) & 0xf;
buf[i] = quadbit > 9 ? quadbit - 10 + 'a' : quadbit + '0';
}
}
void uint32_to_bin(uint32_t number, char buf[32])
{
for (int i = 0; i < 32; i++)
buf[i] = ((number >> (32 - i - 1)) & 1) ? '1' : '0';
}
void uint32_to_decstring(uint32_t number, char buf[11])
{
uint32_to_dec(number, buf);
buf[10] = '\0';
}
void uint32_to_hexstring(uint32_t number, char buf[9])
{
uint32_to_hex(number, buf);
buf[8] = '\0';
}
void uint32_to_binstring(uint32_t number, char buf[33])
{
uint32_to_bin(number, buf);
buf[32] = '\0';
}
void trim_0s(char string[])
{
size_t i;
for (i = 0; string[i] == '0'; i++);
size_t j = 0;
if (!string[i])
string[j++] = string[--i];
do
string[j] = string[i + j];
while (string[j++]);
}
void uint32_to_decstringt(uint32_t number, char buf[11])
{
uint32_to_decstring(number, buf);
trim_0s(buf);
}
void uint32_to_hexstringt(uint32_t number, char buf[9])
{
uint32_to_hexstring(number, buf);
trim_0s(buf);
}
size_t strlen(char string[])
{
size_t len;
for (len = 0; string[len]; len++);
return len;
}
void memcpy(void *dst, void *src, size_t nbytes)
{
size_t iter;
// copying by word is faster than by byte
// copy by word as much as possible
for (iter = 0; iter < nbytes / 4; iter++)
((volatile uint32_t*) dst)[iter] = ((uint32_t*) src)[iter];
// copy the remaining 1, 2 or 3 bytes by byte
for (iter *= 4; iter < nbytes; iter++)
((volatile uint8_t*) dst)[iter] = ((uint8_t*) src)[iter];
}
// keep in mind memset is also needed for array initialization, like
// uint32_t buf[16] = {0};
// gcc compiles this to memset call
void *memset(void *s, int c, size_t n)
{
volatile char *mem = s;
for (size_t i = 0; i < n; i++)
mem[i] = c;
return s;
}
char *strcat(char *dst, const char *src)
{
char *where_to_append;
for (where_to_append = dst; *where_to_append; where_to_append++);
size_t i;
for (i = 0; src[i]; i++)
((char volatile*) where_to_append)[i] = src[i];
((char volatile*) where_to_append)[i] = '\0';
return dst;
}
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