diff --git a/payloads/libpayload/Kconfig b/payloads/libpayload/Kconfig
index b5da2d9a4a..ea9189463b 100644
--- a/payloads/libpayload/Kconfig
+++ b/payloads/libpayload/Kconfig
@@ -505,6 +505,13 @@ config IO_ADDRESS_SPACE
 	  This option is turned on if the target system has a separate
 	  IO address space. This is typically only the case on x86.
 
+config ARCH_HAS_MEM_FUNCTIONS
+	default n
+	bool
+	help
+	  Architectures must select this when they want to override memset,
+	  memcpy and memmove with optimized assembly implementations.
+
 source "arch/arm/Kconfig"
 source "arch/arm64/Kconfig"
 source "arch/x86/Kconfig"
diff --git a/payloads/libpayload/arch/arm/Kconfig b/payloads/libpayload/arch/arm/Kconfig
index 4b88b18ce2..35095115d7 100644
--- a/payloads/libpayload/arch/arm/Kconfig
+++ b/payloads/libpayload/arch/arm/Kconfig
@@ -30,3 +30,4 @@
 
 config ARCH_ARM
 	select LITTLE_ENDIAN
+	select ARCH_HAS_MEM_FUNCTIONS if GPL
diff --git a/payloads/libpayload/arch/arm64/Kconfig b/payloads/libpayload/arch/arm64/Kconfig
index 60beb0bd5a..ea5cd3a48c 100644
--- a/payloads/libpayload/arch/arm64/Kconfig
+++ b/payloads/libpayload/arch/arm64/Kconfig
@@ -30,6 +30,7 @@
 
 config ARCH_ARM64
 	select LITTLE_ENDIAN
+	select ARCH_HAS_MEM_FUNCTIONS
 
 if ARCH_ARM64
 
diff --git a/payloads/libpayload/arch/x86/Kconfig b/payloads/libpayload/arch/x86/Kconfig
index e59bd7ef6a..00b0ad0e70 100644
--- a/payloads/libpayload/arch/x86/Kconfig
+++ b/payloads/libpayload/arch/x86/Kconfig
@@ -31,6 +31,7 @@
 config ARCH_X86
 	select LITTLE_ENDIAN
 	select IO_ADDRESS_SPACE
+	select ARCH_HAS_MEM_FUNCTIONS if GPL
 
 if ARCH_X86
 
diff --git a/payloads/libpayload/arch/x86/string.c b/payloads/libpayload/arch/x86/string.c
index 11bcae7acb..4c0716f446 100644
--- a/payloads/libpayload/arch/x86/string.c
+++ b/payloads/libpayload/arch/x86/string.c
@@ -103,3 +103,45 @@ void *memcpy(void *dest, const void *src, size_t n)
 
 	return dest;
 }
+
+void *memmove(void *dest, const void *src, size_t n)
+{
+	unsigned long d0, d1, d2;
+
+	if (dest < src)
+		return memcpy(dest, src, n);
+
+#if CONFIG(LP_ARCH_X86_64)
+	asm volatile(
+		"std\n\t"
+		"dec %%rdi\n\t"
+		"dec %%rsi\n\t"
+		"rep ; movsb\n\t"
+		"mov %4, %%rcx\n\t"
+		"sub $7, %%rdi\n\t"
+		"sub $7, %%rsi\n\t"
+		"rep ; movsq\n\t"
+		"cld\n\t"
+		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
+		: "0" (n & 7), "g" (n >> 3), "1" (dest + n), "2" (src + n)
+		: "memory"
+	);
+#else
+	asm volatile(
+		"std\n\t"
+		"dec %%edi\n\t"
+		"dec %%esi\n\t"
+		"rep ; movsb\n\t"
+		"mov %4, %%ecx\n\t"
+		"sub $3, %%edi\n\t"
+		"sub $3, %%esi\n\t"
+		"rep ; movsl\n\t"
+		"cld\n\t"
+		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
+		: "0" (n & 3), "g" (n >> 2), "1" (dest + n), "2" (src + n)
+		: "memory"
+	);
+#endif
+
+	return dest;
+}
diff --git a/payloads/libpayload/include/string.h b/payloads/libpayload/include/string.h
index b0028228eb..40776ff78e 100644
--- a/payloads/libpayload/include/string.h
+++ b/payloads/libpayload/include/string.h
@@ -43,6 +43,15 @@ void *memchr(const void *s, int c, size_t n);
 int memcmp(const void *s1, const void *s2, size_t len);
 /** @} */
 
+/**
+ * @defgroup default memory functions remain available under separate names, in
+ * case architecture implementations want to fall back to them in certain cases.
+ */
+void *default_memset(void *s, int c, size_t n);
+void *default_memcpy(void *dst, const void *src, size_t n);
+void *default_memmove(void *dst, const void *src, size_t n);
+/** @} */
+
 /**
  * @defgroup string String functions
  * @{
diff --git a/payloads/libpayload/libc/memory.c b/payloads/libpayload/libc/memory.c
index fff295e54c..80d7a5f507 100644
--- a/payloads/libpayload/libc/memory.c
+++ b/payloads/libpayload/libc/memory.c
@@ -32,7 +32,7 @@
 
 #include <libpayload.h>
 
-static void *default_memset(void *const s, const int c, size_t n)
+void *default_memset(void *const s, const int c, size_t n)
 {
 	size_t i;
 	u8 *dst = s;
@@ -57,10 +57,7 @@ static void *default_memset(void *const s, const int c, size_t n)
 	return s;
 }
 
-void *memset(void *s, int c, size_t n)
-	__attribute__((weak, alias("default_memset")));
-
-static void *default_memcpy(void *dst, const void *src, size_t n)
+void *default_memcpy(void *dst, const void *src, size_t n)
 {
 	size_t i;
 	void *ret = dst;
@@ -81,10 +78,7 @@ static void *default_memcpy(void *dst, const void *src, size_t n)
 	return ret;
 }
 
-void *memcpy(void *dst, const void *src, size_t n)
-	__attribute__((weak, alias("default_memcpy")));
-
-static void *default_memmove(void *dst, const void *src, size_t n)
+void *default_memmove(void *dst, const void *src, size_t n)
 {
 	size_t offs;
 	ssize_t i;
@@ -110,8 +104,14 @@ static void *default_memmove(void *dst, const void *src, size_t n)
 	return dst;
 }
 
+#if !CONFIG(LP_ARCH_HAS_MEM_FUNCTIONS)
+void *memcpy(void *dst, const void *src, size_t n)
+	__attribute__((alias("default_memcpy")));
+void *memset(void *s, int c, size_t n)
+	__attribute__((alias("default_memset")));
 void *memmove(void *dst, const void *src, size_t n)
-	__attribute__((weak, alias("default_memmove")));
+	__attribute__((alias("default_memmove")));
+#endif
 
 /**
  * Compare two memory areas.
@@ -124,7 +124,7 @@ void *memmove(void *dst, const void *src, size_t n)
  * 	   greater than s2 respectively.
  */
 
-static int default_memcmp(const void *s1, const void *s2, size_t n)
+int memcmp(const void *s1, const void *s2, size_t n)
 {
 	size_t i = 0;
 	const unsigned long *w1 = s1, *w2 = s2;
@@ -142,9 +142,6 @@ static int default_memcmp(const void *s1, const void *s2, size_t n)
 	return 0;
 }
 
-int memcmp(const void *s1, const void *s2, size_t n)
-	__attribute__((weak, alias("default_memcmp")));
-
 void *memchr(const void *s, int c, size_t n)
 {
 	unsigned char *p = (unsigned char *)s;