feat(ex00): done

ex00/src/lib/utils.c

@@ -0,0 +1,125 @@
+#include "lib/utils.h"
+#include "lib/mystd.h"
+#include "lib/uart.h"
+
+// this just burns cycles.
+// the volatile is important, it means that the cpu can't optimize any
+// read/writes for the value
+static inline void spin_loop(volatile uint16_t counts) {
+	while (counts)
+		counts--;
+}
+
+void delay_ms(uint16_t ms) {
+	while (ms) {
+		// this value was taken using a delay of 500ms, and just recording the led
+		// blinking. it seems to be high enough such that each loop of delay_loop
+		// takes 1ms :D
+		spin_loop((F_CPU) / 5000);
+		ms--;
+	}
+}
+
+void ft_bzero(void* data, uint16_t size) {
+	char* d = data;
+	while (size) {
+		*d = 0;
+		d++;
+		size--;
+	}
+}
+
+uint8_t ft_stridx(const char* str, char chr) {
+	if (!str)
+		return -1;
+	for (uint8_t i = 0; str[i]; i++) {
+		if (str[i] == chr)
+			return i;
+	}
+	return -1;
+}
+
+static float ft_pow(float base, float count) {
+	float out = 1;
+
+	while (count--)
+		out *= base;
+	return out;
+}
+
+// Reverses a string 'str' of length 'len'
+static void reverse(char* str, uint16_t len) {
+	uint16_t i = 0, j = len - 1, temp;
+	while (i < j) {
+		temp   = str[i];
+		str[i] = str[j];
+		str[j] = temp;
+		i++;
+		j--;
+	}
+}
+
+static uint16_t ft_itoa(uint32_t value, char* out, uint16_t width) {
+	uint16_t i = 0;
+	if (value == 0) {
+		while (i < width)
+			out[i++] = '0';
+		return i;
+	}
+	while (value) {
+		out[i++] = (value % 10) + '0';
+		value	 = value / 10;
+	}
+
+	// If number of digits required is more, then
+	// add 0s at the beginning
+	while (i < width)
+		out[i++] = '0';
+
+	// we need to reverse the data
+	reverse(out, i);
+	out[i] = 0;
+
+	return i;
+}
+// 0.3250351
+// Converts a floating-point/double number to a string.
+uint8_t ft_ftoa(float val, char* out, uint16_t precision) {
+	uint32_t ipart = (uint32_t)val;
+	float	 fpart = val - (float)ipart;
+
+	// convert integer part to string
+	uint8_t i	   = ft_itoa(ipart, out, 1);
+
+	if (precision != 0) {
+		out[i] = '.';
+		fpart  = fpart * ft_pow(10.f, precision);
+		i	  += ft_itoa((uint32_t)fpart, &out[i + 1], precision);
+	}
+	return i;
+}
+
+void* ft_memcpy(void* dest, void* src, uint16_t len) {
+	for (uint16_t i = 0; i < len; i++)
+		((uint8_t*)dest)[i] = ((uint8_t*)src)[i];
+	return dest;
+}
+
+bool ft_memcmp(void* s1, void* s2, uint16_t len) {
+	for (uint16_t i = 0; i < len; i++) {
+		if (((uint8_t*)s1)[i] != ((uint8_t*)s2)[i])
+			return false;
+	}
+	return true;
+}
+
+uint8_t is_hex_digit(char chr) {
+	uint8_t i;
+	if ((i = ft_stridx("0123456789", chr)) != 255)
+		return i;
+	if ((i = ft_stridx("abcdef", chr)) != 255)
+		return 10 + i;
+	if ((i = ft_stridx("ABCDEF", chr)) != 255)
+		return 10 + i;
+	return 255;
+}