initial implementation of klibc

fix linker error about ctx_switch

kernel/context_switch.asm

@@ -1,4 +1,4 @@
-.global ctx_switch
+global ctx_switch
 
 ; void ctx_switch(uint32_t **old_sp_ptr, uint32_t *new_sp);
 ; Arguments on stack (cdecl convention):

kernel/memory.c

@@ -1,6 +1,6 @@
 #include "memory.h"
 
-/* note: this is a stub, please use care as theres duplicate functions in utils implementation 
+/* 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)
  * --------------------------------------------------------------------- */
@@ -15,124 +15,3 @@ static inline void byte_copy_backward(uint8_t *dst, const uint8_t *src, size_t 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;
-}

kernel/types.h

@@ -27,7 +27,6 @@ typedef enum { false = 0, true = 1 } bool;
 // ----------------------------
 // OS subsystem types
 // ----------------------------
-typedef uint32_t size_t;
 typedef int32_t  ssize_t;
 
 typedef uint32_t phys_addr_t; // Physical address

kernel/utils.c

@@ -76,10 +76,3 @@ char* utoa(unsigned int value, char* str, int base) {
     reverse(str, i);
     return str;
 }
-
-void *memset(void *dest, int value, size_t len) {
-    unsigned char *ptr = (unsigned char *)dest;
-    while (len-- > 0)
-        *ptr++ = (unsigned char)value;
-    return dest;
-}

kernel/utils.h

@@ -1,6 +1,8 @@
 #ifndef UTILS_H
 #define UTILS_H
 
+#include <stddef.h>
+
 #include "types.h"
 
 // Convert integer to string (base is typically 10, 16, etc.)