Create memory.c

This is the implementation for memory.c memory.h pair to house the 
memset. memcmp, memcpy, memmove etc careful as there are now duplicates in utils implementation

kernel/memory.c

@@ -0,0 +1,138 @@
+#include "memory.h"
+
+/* note: this is a stub, please use care as theres duplicate functions in utils implementation 
+/* --------------------------------------------------------------------- *
+ *  Helper: copy a single byte (used by both memcpy and memmove)
+ * --------------------------------------------------------------------- */
+static inline void byte_copy_forward(uint8_t *dst, const uint8_t *src, size_t n)
+{
+    while (n--) *dst++ = *src++;
+}
+
+static inline void byte_copy_backward(uint8_t *dst, const uint8_t *src, size_t n)
+{
+    dst += n; src += n;
+    while (n--) *--dst = *--src;
+}
+
+/* --------------------------------------------------------------------- *
+ *  memcpy  –  no overlap allowed (behaviour undefined if overlap)
+ * --------------------------------------------------------------------- */
+void *memcpy(void *restrict dst, const void *restrict src, size_t n)
+{
+    uint8_t *d = (uint8_t *)dst;
+    const uint8_t *s = (const uint8_t *)src;
+
+#if defined(MEMORY_OPTIMIZED)
+    /* Align destination to 4-byte boundary */
+    size_t align = (uintptr_t)d & 3U;
+    if (align) {
+        size_t head = 4 - align;
+        if (head > n) head = n;
+        byte_copy_forward(d, s, head);
+        d += head; s += head; n -= head;
+    }
+
+    /* 32-bit word copy – safe because we already aligned dst */
+    {
+        uint32_t *d32 = (uint32_t *)d;
+        const uint32_t *s32 = (const uint32_t *)s;
+        size_t words = n / 4;
+        while (words--) *d32++ = *s32++;
+        d = (uint8_t *)d32;
+        s = (const uint8_t *)s32;
+        n &= 3;
+    }
+#endif
+
+    byte_copy_forward(d, s, n);
+    return dst;
+}
+
+/* --------------------------------------------------------------------- *
+ *  memmove – handles overlapping regions correctly
+ * --------------------------------------------------------------------- */
+void *memmove(void *dst, const void *src, size_t n)
+{
+    uint8_t *d = (uint8_t *)dst;
+    const uint8_t *s = (const uint8_t *)src;
+
+    if (n == 0 || dst == src)
+        return dst;
+
+    if (d < s) {                     /* copy forward */
+#if defined(MEMORY_OPTIMIZED)
+        /* Same fast path as memcpy when no overlap */
+        size_t align = (uintptr_t)d & 3U;
+        if (align) {
+            size_t head = 4 - align;
+            if (head > n) head = n;
+            byte_copy_forward(d, s, head);
+            d += head; s += head; n -= head;
+        }
+        {
+            uint32_t *d32 = (uint32_t *)d;
+            const uint32_t *s32 = (const uint32_t *)s;
+            size_t words = n / 4;
+            while (words--) *d32++ = *s32++;
+            d = (uint8_t *)d32;
+            s = (const uint8_t *)s32;
+            n &= 3;
+        }
+#endif
+        byte_copy_forward(d, s, n);
+    } else {                         /* copy backward */
+        byte_copy_backward(d, s, n);
+    }
+    return dst;
+}
+
+/* --------------------------------------------------------------------- *
+ *  memcmp  – lexicographical compare
+ * --------------------------------------------------------------------- */
+int memcmp(const void *s1, const void *s2, size_t n)
+{
+    const uint8_t *a = (const uint8_t *)s1;
+    const uint8_t *b = (const uint8_t *)s2;
+
+#if defined(MEMORY_OPTIMIZED)
+    /* Align to 4-byte boundary */
+    size_t align = (uintptr_t)a & 3U;
+    if (align && align == ((uintptr_t)b & 3U)) {
+        size_t head = 4 - align;
+        if (head > n) head = n;
+        while (head--) {
+            int diff = *a++ - *b++;
+            if (diff) return diff;
+        }
+        n -= head;
+    }
+
+    {
+        const uint32_t *a32 = (const uint32_t *)a;
+        const uint32_t *b32 = (const uint32_t *)b;
+        size_t words = n / 4;
+        while (words--) {
+            uint32_t va = *a32++, vb = *b32++;
+            if (va != vb) {
+                /* byte-wise fallback for the differing word */
+                const uint8_t *pa = (const uint8_t *)(a32 - 1);
+                const uint8_t *pb = (const uint8_t *)(b32 - 1);
+                for (int i = 0; i < 4; ++i) {
+                    int diff = pa[i] - pb[i];
+                    if (diff) return diff;
+                }
+            }
+        }
+        a = (const uint8_t *)a32;
+        b = (const uint8_t *)b32;
+        n &= 3;
+    }
+#endif
+
+    while (n--) {
+        int diff = *a++ - *b++;
+        if (diff) return diff;
+    }
+    return 0;
+}