Fix gcc 10 link issues

- avoid linker error by providing string.[ch] in bootrom

bootrom/string.c

@@ -0,0 +1,104 @@
+//-----------------------------------------------------------------------------
+// Jonathan Westhues, Sept 2005
+//
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
+// Common string.h functions
+//-----------------------------------------------------------------------------
+
+#include "string.h"
+#include <stdint.h>
+
+void *memcpy(void *dest, const void *src, size_t len) {
+	uint8_t *d = dest;
+	const uint8_t *s = src;
+	while((len--) > 0) {
+		*d = *s;
+		d++;
+		s++;
+	}
+	return dest;
+}
+
+
+void *memset(void *dest, int c, size_t len) {
+	uint8_t *d = dest;
+	while((len--) > 0) {
+		*d = c;
+		d++;
+	}
+	return dest;
+}
+
+
+void *memmove(void *dest, const void *src, size_t len) {
+	uint8_t *d = dest;
+	const uint8_t *s = src;
+	if (dest <= src) {
+		while((len--) > 0) {
+			*d = *s;
+			d++;
+			s++;
+		} 
+	} else {
+		d = d + len - 1;
+		s = s + len - 1;
+		while((len--) > 0) {
+			*d = *s;
+			d--;
+			s--;
+		}
+	}
+	return dest;
+}
+
+
+int memcmp(const void *av, const void *bv, size_t len) {
+	const uint8_t *a = av;
+	const uint8_t *b = bv;
+
+	while((len--) > 0) {
+		if(*a != *b) {
+			return *a - *b;
+		}
+		a++;
+		b++;
+	}
+	return 0;
+}
+
+
+size_t strlen(const char *str) {
+	int l = 0;
+	while(*str) {
+		l++;
+		str++;
+	}
+	return l;
+}
+
+
+char* strncat(char *dest, const char *src, size_t n) {
+	unsigned int dest_len = strlen(dest);
+	unsigned int i;
+
+	for (i = 0 ; i < n && src[i] != '\0' ; i++)
+		dest[dest_len + i] = src[i];
+	dest[dest_len + i] = '\0';
+
+	return dest;
+}
+
+
+char* strcat(char *dest, const char *src) {
+	unsigned int dest_len = strlen(dest);
+	unsigned int i;
+
+	for (i = 0 ; src[i] != '\0' ; i++)
+		dest[dest_len + i] = src[i];
+	dest[dest_len + i] = '\0';
+
+	return dest;
+}