Configuration via command line

src/main.c

@@ -4,6 +4,8 @@
 #include <string.h>
 #include <errno.h>
 #include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
 
 #include "sk6812.h"
 #include "logger.h"
@@ -12,17 +14,78 @@
 
 #define PORT 2703
 
-#define NUM_MODULES 300
-#define GPIO_IDX    961
-#define BASE_ADDR   ((void*)0x40010000U)
+#define NUM_MODULES 60
+#define GPIO_IDX    960
+#define BASE_ADDR   ((void*)0x40000000U)
 
-int main(void)
+struct CmdLineArgs {
+	uint16_t port;
+	void    *base_addr;
+	uint32_t gpio_idx;
+	uint32_t num_modules;
+};
+
+int parse_args(int argc, char **argv, struct CmdLineArgs *args)
+{
+	int opt;
+	unsigned long tmp_ul;
+	unsigned long long tmp_ull;
+
+	while((opt = getopt(argc, argv, "p:a:g:n:")) != -1) {
+		switch(opt) {
+			case 'p': // port
+				tmp_ul = strtoul(optarg, NULL, 0);
+				if(tmp_ul < 1 || tmp_ul > 65535) {
+					LOG(LVL_ERR, "Port number is out of range [1..65535]: %ul", tmp_ul);
+					return -1;
+				}
+
+				args->port = (uint16_t)tmp_ul;
+				break;
+
+			case 'a': // base address
+				tmp_ull = strtoull(optarg, NULL, 0);
+				args->base_addr = (void*)tmp_ull;
+				break;
+
+			case 'g': // gpio
+				args->gpio_idx = strtoul(optarg, NULL, 0);
+				break;
+
+			case 'n': // number of modules
+				args->num_modules = strtoul(optarg, NULL, 0);
+				break;
+
+			default:
+				return -1;
+		}
+	}
+
+	return 0;
+}
+
+int main(int argc, char **argv)
 {
 	struct sk6812_ctx ctx;
 
-	// initialize logger	
+	struct CmdLineArgs args;
+
+	// initialize logger
 	logger_init();
 
+	// default arguments
+	args.port = PORT;
+	args.base_addr = BASE_ADDR;
+	args.gpio_idx = GPIO_IDX;
+	args.num_modules = NUM_MODULES;
+
+	// parse command line arguments
+	if(parse_args(argc, argv, &args) == -1) {
+		LOG(LVL_FATAL, "Error while parsing command line arguments!\n\n"
+				"Usage: %s [-p port] [-a base_address] [-g gpio_index] [-n number_of_modules]\n\n", argv[0]);
+		return 1;
+	}
+
 	// initialise the UDP server
 	if(udpproto_init(PORT) == -1) {
 		LOG(LVL_FATAL, "Could not initialize the UDP server.");