tools: Move copyfile() into a common file

This function is useful in other places. Move it to a common file.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/fit_common.c

@@ -119,3 +119,59 @@ err:
 
 	return -1;
 }
+
+int copyfile(const char *src, const char *dst)
+{
+	int fd_src = -1, fd_dst = -1;
+	void *buf = NULL;
+	ssize_t size;
+	size_t count;
+	int ret = -1;
+
+	fd_src = open(src, O_RDONLY);
+	if (fd_src < 0) {
+		printf("Can't open file %s (%s)\n", src, strerror(errno));
+		goto out;
+	}
+
+	fd_dst = open(dst, O_WRONLY | O_CREAT, 0666);
+	if (fd_dst < 0) {
+		printf("Can't open file %s (%s)\n", dst, strerror(errno));
+		goto out;
+	}
+
+	buf = calloc(1, 512);
+	if (!buf) {
+		printf("Can't allocate buffer to copy file\n");
+		goto out;
+	}
+
+	while (1) {
+		size = read(fd_src, buf, 512);
+		if (size < 0) {
+			printf("Can't read file %s\n", src);
+			goto out;
+		}
+		if (!size)
+			break;
+
+		count = size;
+		size = write(fd_dst, buf, count);
+		if (size < 0) {
+			printf("Can't write file %s\n", dst);
+			goto out;
+		}
+	}
+
+	ret = 0;
+
+ out:
+	if (fd_src >= 0)
+		close(fd_src);
+	if (fd_dst >= 0)
+		close(fd_dst);
+	if (buf)
+		free(buf);
+
+	return ret;
+}