diff --git a/README b/README
index 64258bb..cc4c741 100644
--- a/README
+++ b/README
@@ -19,20 +19,36 @@ from sandbox/cdba/cdba-server. Available devices are read from $HOME/.cdba
 = Client side
 The client is invoked as:
 
-  cdba -b <board> [-h <host>] [-c <power-cylce-count>] [-s <status-fifo>] [boot.img]
+  cdba -b <board> [-h <host>] [-S <server>] [-c <power-cycle-count>]
+       [-C <power-cycle-count>] [-R] [-s <status-fifo>]
+       [-t <timeout>] [-T <inactivity-timeout>]
+       [write <target> <image>]... [boot.img]
+  cdba -i -b <board> [-h <host>] [-S <server>]
+  cdba -l [-h <host>] [-S <server>]
 
 <host> will be connected to using ssh and <board> will be selected for
 operation. As the board's fastboot interface shows up the given boot.img
 will be transfered and booted on the device. If <host> is omitted, the
-cdba-server is started locally without using ssh. If [boot.img] is omitted,
-"fastboot continue" is run to boot the installed operating system.
+cdba-server is started locally without using ssh. The -S option can be used
+to specify an alternative cdba-server binary or command. If [boot.img] is
+omitted, "fastboot continue" is run to boot the installed operating system.
+
+The optional write <target> <image> arguments can be repeated to flash one or
+more images through EDL before booting or continuing the board.
 
 The board will execute until the key sequence ^A q is invoked or the board
 outputs a sequence of 20 ~ (tilde) chards in a row.
 
 If the optional -c is given, the board will upon receiving the tilde sequence
 restart the board the given number of times. Each time booting the given
-boot.img.
+boot.img. If -C is given instead, the board is only power-cycled for the tilde
+sequence and not for timeouts.
+
+The optional -t argument controls the total timeout in seconds, and can be set
+to 0 to disable the total timeout. The optional -T argument specifies an
+inactivity timeout in seconds.
+
+The optional -R argument repeats the fastboot boot when fastboot reappears.
 
 The optional -s argument can be used to specify that a fifo should be created
 and opened. cdba will request the server to start sending status/measurement
diff --git a/cdba.c b/cdba.c
index 68cbdc3..6bcfef5 100644
--- a/cdba.c
+++ b/cdba.c
@@ -610,13 +610,25 @@ static void usage(void)
 {
 	extern const char *__progname;
 
-	fprintf(stderr, "usage: %s -b <board> [-h <host>] [-t <timeout>] "
-			"[-T <inactivity-timeout>] [boot.img]\n",
+	fprintf(stderr, "usage: %s -b <board> [options] "
+			"[write <target> <image>]... [boot.img]\n",
 			__progname);
-	fprintf(stderr, "usage: %s -i -b <board> [-h <host>]\n",
+	fprintf(stderr, "usage: %s -i -b <board> [connection-options]\n",
 			__progname);
-	fprintf(stderr, "usage: %s -l [-h <host>]\n",
+	fprintf(stderr, "usage: %s -l [connection-options]\n",
 			__progname);
+	fprintf(stderr, "\n");
+	fprintf(stderr, "connection-options:\n");
+	fprintf(stderr, "  -h <host>        connect to remote host using ssh\n");
+	fprintf(stderr, "  -S <server>      cdba-server binary or command\n");
+	fprintf(stderr, "\n");
+	fprintf(stderr, "boot options:\n");
+	fprintf(stderr, "  -c <count>       power-cycle count on timeout or power-off marker\n");
+	fprintf(stderr, "  -C <count>       power-cycle count on power-off marker only\n");
+	fprintf(stderr, "  -R               repeat fastboot boot when fastboot reappears\n");
+	fprintf(stderr, "  -s <fifo>        write status updates to fifo\n");
+	fprintf(stderr, "  -t <seconds>     total timeout, 0 disables it (default: 600)\n");
+	fprintf(stderr, "  -T <seconds>     inactivity timeout\n");
 	exit(1);
 }