flashcp: Add option -A/--erase-all

index c46a5b4..b6ad2f9 100644
@@ -66,6 +66,7 @@
 #define FLAG_HELP		0x02
 #define FLAG_FILENAME	0x04
 #define FLAG_DEVICE		0x08
+#define FLAG_ERASE_ALL	0x10
 
 /* error levels */
 #define LOG_NORMAL	1

@@ -89,12 +90,13 @@ static NORETURN void showusage(bool error)
 			"\n"
 			"Flash Copy - Written by Abraham van der Merwe <[email protected]>\n"
 			"\n"
-			"usage: %1$s [ -v | --verbose ] <filename> <device>\n"
+			"usage: %1$s [ -v | --verbose | -A | --erase-all ] <filename> <device>\n"
 			"       %1$s -h | --help\n"
 			"       %1$s -V | --version\n"
 			"\n"
 			"   -h | --help      Show this help message\n"
 			"   -v | --verbose   Show progress reports\n"
+			"   -A | --erase-all Erases the whole device regardless of the image size\n"
 			"   -V | --version   Show version information and exit\n"
 			"   <filename>       File which you want to copy to flash\n"
 			"   <device>         Flash device to write to (e.g. /dev/mtd0, /dev/mtd1, etc.)\n"

@@ -179,10 +181,11 @@ int main (int argc,char *argv[])
 
 	for (;;) {
 		int option_index = 0;
-		static const char *short_options = "hvV";
+		static const char *short_options = "hvAV";
 		static const struct option long_options[] = {
 			{"help", no_argument, 0, 'h'},
 			{"verbose", no_argument, 0, 'v'},
+			{"erase-all", no_argument, 0, 'A'},
 			{"version", no_argument, 0, 'V'},
 			{0, 0, 0, 0},
 		};

@@ -202,6 +205,10 @@ int main (int argc,char *argv[])
 				flags |= FLAG_VERBOSE;
 				DEBUG("Got FLAG_VERBOSE\n");
 				break;
+			case 'A':
+				flags |= FLAG_ERASE_ALL;
+				DEBUG("Got FLAG_ERASE_ALL\n");
+				break;
 			case 'V':
 				common_print_version();
 				exit(EXIT_SUCCESS);

@@ -257,8 +264,16 @@ int main (int argc,char *argv[])
 #warning "Check for smaller erase regions"
 
 	erase.start = 0;
-	erase.length = (filestat.st_size + mtd.erasesize - 1) / mtd.erasesize;
-	erase.length *= mtd.erasesize;
+
+	if (flags & FLAG_ERASE_ALL)
+	{
+		erase.length = mtd.size;
+	}
+	else
+	{
+		erase.length = (filestat.st_size + mtd.erasesize - 1) / mtd.erasesize;
+		erase.length *= mtd.erasesize;
+	}
 
 	if (flags & FLAG_VERBOSE)
 	{