main: Use built-in memcpy

Signed-off-by: Markuss Broks <markuss.broks@gmail.com>

include/main.h

@@ -3,6 +3,8 @@
  * Copyright (c) 2022, Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
  */
 
+#include <stddef.h>
+
 #ifndef MAIN_H_   /* Include guard */
 #define MAIN_H_
 
@@ -13,14 +15,35 @@ extern void board_init(void);
 
 extern void printk(char *text);
 
-/* Define our own 128 bit memcpy */
+#ifndef __has_builtin
-void memcpy(void *dest, void *src, int size)
+	#define __has_builtin(x) 0
-{
+#endif
-	unsigned __int128 *src2 = src;
+
-	unsigned __int128 *dest2 = dest;
+#if __has_builtin(__builtin_memcpy)
+	void memcpy(void *dest, void *src, size_t size) {
+		__builtin_memcpy(dest, src, size);
+	}
+#else
+	#ifdef __aarch64__
+		/* Define our own 128 bit memcpy */
+		void memcpy(void *dest, void *src, size_t size)
+		{
+			unsigned __int128 *src2 = src;
+			unsigned __int128 *dest2 = dest;
+
+			for (size_t i = 0; i < size / 16; i++)
+				dest2[i] = src2[i];
+		}
+	#endif
+
+	#ifdef __arm__
+		void memcpy (char* src, char* dest, size_t len) {
+			for (size_t i = 0; i < len; i++)
+				dest[i] = src[i];
+		}
+	#endif
+#endif
+
 
-	for (int i=0; i<size/16; i++)
-		dest2[i] = src2[i];
-}
 
 #endif // MAIN_H_

main/main.c

@@ -17,6 +17,6 @@ void main(void* dt, void* kernel) {
 
 	/* Copy kernel to memory and boot  */
 	printk("Booting linux...");
-	memcpy((void*)CONFIG_PAYLOAD_ENTRY, kernel, (unsigned long) &kernel_size);
+	__builtin_memcpy((void*)CONFIG_PAYLOAD_ENTRY, kernel, (unsigned long) &kernel_size);
 	load_kernel(dt, 0, 0, 0, (void*)CONFIG_PAYLOAD_ENTRY);	
 }