feat: Vfs and Ext2 support. Code style/attribute improvements

Added VFS and Ext2 support.
Optimized attributes of methods to improve code highlighting.
Printf attribute, malloc attribute, etc.

kernel/libc/string.c

@@ -22,7 +22,7 @@ void *memset(void *dst, int data, size_t amount) {
 }
 
 void *memmove(void *dst, const void *src, size_t amount) {
-    void* tmp = malloc(amount);
+    void *tmp = malloc(amount);
     if (tmp == NULL) {
         return NULL;
     }
@@ -48,16 +48,19 @@ size_t strlen(const char *str) {
 }
 
 int strcmp(const char *s1, const char *s2) {
-    int len1 = strlen(s1);
-    int len2 = strlen(s2);
+    size_t len1 = strlen(s1);
+    size_t len2 = strlen(s2);
     return strncmp(s1, s2, MAX(len1, len2));
 }
 
-const char *strchr(const char *s, char c) {
-    int index = 0;
+char *strchr(const char *s, char c) {
+    size_t index = 0;
     while (1) {
         if (s[index] == c) {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wincompatible-pointer-types-discards-qualifiers"
             return &s[index];
+#pragma clang diagnostic pop
         }
         if (s[index] == 0) {
             return NULL;
@@ -66,11 +69,14 @@ const char *strchr(const char *s, char c) {
     }
 }
 
-const char *strrchr(const char *s, char c) {
-    int index = strlen(s);
+char *strrchr(const char *s, char c) {
+    size_t index = strlen(s);
     while (1) {
         if (s[index] == c) {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wincompatible-pointer-types-discards-qualifiers"
             return &s[index];
+#pragma clang diagnostic pop
         }
         if (index == 0) {
             return NULL;
@@ -90,8 +96,8 @@ int memcmp(const void *s1, const void *s2, size_t n) {
     return 0;
 }
 
-int strncmp(const char *s1, const char *s2, int n) {
-    for (int i = 0; i < n; ++i) {
+int strncmp(const char *s1, const char *s2, size_t n) {
+    for (size_t i = 0; i < n; ++i) {
         if (s1[i] == 0 && s2[i] == 0) {
             return 0;
         }