[settings] Modify "set" command to allow space separated values

Allow multiple, space separated values (such as kernel arguments,
passed via DHCP) to be assigned to an identifier using the "set"
command.

Originally-implemented-by: Aaron Brooks <aaron@brooks1.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/hci/commands/nvo_cmd.c

 }
 
 static int set_exec ( int argc, char **argv ) {
+	size_t len;
+	int i;
 	int rc;
 
-	if ( argc != 3 ) {
+	if ( argc < 3 ) {
 		printf ( "Syntax: %s <identifier> <value>\n", argv[0] );
 		return 1;
 	}
 
-	if ( ( rc = storef_named_setting ( argv[1], argv[2] ) ) != 0 ) {
-		printf ( "Could not set \"%s\"=\"%s\": %s\n",
-			 argv[1], argv[2], strerror ( rc ) );
-		return 1;
+	/* Determine total length of command line */
+	len = 1; /* NUL */
+	for ( i = 2 ; i < argc ; i++ )
+		len += ( 1 /* possible space */ + strlen ( argv[i] ) );
+
+	{
+		char buf[len];
+		char *ptr = buf;
+
+		/* Assemble command line */
+		buf[0] = '\0';
+		for ( i = 2 ; i < argc ; i++ ) {
+			ptr += sprintf ( ptr, "%s%s", ( buf[0] ? " " : "" ),
+					 argv[i] );
+		}
+		assert ( ptr < ( buf + len ) );
+
+		if ( ( rc = storef_named_setting ( argv[1], buf ) ) != 0 ) {
+			printf ( "Could not set \"%s\"=\"%s\": %s\n",
+				 argv[1], buf, strerror ( rc ) );
+			return 1;
+		}
 	}
 
 	return 0;