Bootloader pre-release

liba/Makefile

@@ -24,6 +24,7 @@ liba_src += $(addprefix liba/src/, \
   strlcpy.c \
   strlen.c \
   external/sqlite/mem5.c \
+  itoa.c \
 )
 
 liba_src += $(addprefix liba/src/external/openbsd/, \

liba/include/stdlib.h

@@ -10,6 +10,7 @@ void free(void *ptr);
 void * malloc(size_t size);
 void * realloc(void *ptr, size_t size);
 void * calloc(size_t count, size_t size);
+char * itoa(int value, char *str, int base);
 
 void abort(void) __attribute__((noreturn));
 

liba/src/itoa.c

@@ -0,0 +1,60 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+// https://www.techiedelight.com/implement-itoa-function-in-c/
+
+// Function to swap two numbers
+void swap(char *x, char *y) {
+    char t = *x; *x = *y; *y = t;
+}
+ 
+// Function to reverse `buffer[i…j]`
+char* reverse(char *buffer, int i, int j) {
+    while (i < j) {
+        swap(&buffer[i++], &buffer[j--]);
+    }
+ 
+    return buffer;
+}
+ 
+// Iterative function to implement `itoa()` function in C
+char* itoa(int value, char* buffer, int base) {
+    // invalid input
+    if (base < 2 || base > 32) {
+        return buffer;
+    }
+ 
+    // consider the absolute value of the number
+    int n = abs(value);
+ 
+    int i = 0;
+    while (n) {
+        int r = n % base;
+ 
+        if (r >= 10) {
+            buffer[i++] = 65 + (r - 10);
+        }
+        else {
+            buffer[i++] = 48 + r;
+        }
+ 
+        n = n / base;
+    }
+ 
+    // if the number is 0
+    if (i == 0) {
+        buffer[i++] = '0';
+    }
+ 
+    // If the base is 10 and the value is negative, the resulting string
+    // is preceded with a minus sign (-)
+    // With any other base, value is always considered unsigned
+    if (value < 0 && base == 10) {
+        buffer[i++] = '-';
+    }
+ 
+    buffer[i] = '\0'; // null terminate string
+ 
+    // reverse the string and return it
+    return reverse(buffer, 0, i - 1);
+}