cert_create: specify command line options in the CoT

This patch introduces a new API that allows to specify command
line options in the Chain of Trust description. These command line
options may be used to specify parameters related to the CoT (i.e.
keys or certificates), instead of keeping a hardcoded list of
options in main.c.

Change-Id: I282b0b01cb9add557b26bddc238a28253ce05e44
diff --git a/tools/cert_create/src/cmd_opt.c b/tools/cert_create/src/cmd_opt.c
new file mode 100644
index 0000000..3847b98
--- /dev/null
+++ b/tools/cert_create/src/cmd_opt.c
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <getopt.h>
+#include <stddef.h>
+#include <cmd_opt.h>
+
+/* Command line options */
+static struct option long_opt[CMD_OPT_MAX_NUM+1];
+static int num_reg_opt;
+
+int cmd_opt_add(const char *name, int has_arg, int val)
+{
+	if (num_reg_opt >= CMD_OPT_MAX_NUM) {
+		return -1;
+	}
+	long_opt[num_reg_opt].name = name;
+	long_opt[num_reg_opt].has_arg = has_arg;
+	long_opt[num_reg_opt].flag = 0;
+	long_opt[num_reg_opt].val = val;
+	num_reg_opt++;
+
+	return 0;
+}
+
+const struct option *cmd_opt_get_array(void)
+{
+	return long_opt;
+}
+
+const char *cmd_opt_get_name(int idx)
+{
+	if (idx >= num_reg_opt) {
+		return NULL;
+	}
+
+	return long_opt[idx].name;
+}