diff --git a/alpaca.c b/alpaca.c
index fd7e996..12f4c99 100644
--- a/alpaca.c
+++ b/alpaca.c
@@ -42,7 +42,7 @@
 #include <unistd.h>
 
 #include "cdba-server.h"
-#include "alpaca.h"
+#include "device.h"
 
 struct alpaca {
 	int alpaca_fd;
@@ -53,7 +53,7 @@ struct alpaca {
 static int alpaca_device_power(struct alpaca *alpaca, int on);
 static int alpaca_usb_device_power(struct alpaca *alpaca, int on);
 
-void *alpaca_open(struct device *dev)
+static void *alpaca_open(struct device *dev)
 {
 	struct alpaca *alpaca;
 
@@ -121,7 +121,7 @@ static int alpaca_power_off(struct device *dev)
 	return 0;
 }
 
-int alpaca_power(struct device *dev, bool on)
+static int alpaca_power(struct device *dev, bool on)
 {
 	if (on)
 		return alpaca_power_on(dev);
@@ -129,14 +129,14 @@ int alpaca_power(struct device *dev, bool on)
 		return alpaca_power_off(dev);
 }
 
-void alpaca_usb(struct device *dev, bool on)
+static void alpaca_usb(struct device *dev, bool on)
 {
 	struct alpaca *alpaca = dev->cdb;
 
 	alpaca_usb_device_power(alpaca, on);
 }
 
-void alpaca_key(struct device *dev, int key, bool asserted)
+static void alpaca_key(struct device *dev, int key, bool asserted)
 {
 	switch (key) {
 	case DEVICE_KEY_FASTBOOT:
@@ -147,3 +147,10 @@ void alpaca_key(struct device *dev, int key, bool asserted)
 		break;
 	}
 }
+
+const struct control_ops alpaca_ops = {
+	.open = alpaca_open,
+	.power = alpaca_power,
+	.usb = alpaca_usb,
+	.key = alpaca_key,
+};
diff --git a/alpaca.h b/alpaca.h
deleted file mode 100644
index 930d35c..0000000
--- a/alpaca.h
+++ /dev/null
@@ -1,13 +0,0 @@
-#ifndef __ALPACA_H__
-#define __ALPACA_H__
-
-#include "device.h"
-
-struct alpaca;
-
-void *alpaca_open(struct device *dev);
-int alpaca_power(struct device *dev, bool on);
-void alpaca_usb(struct device *dev, bool on);
-void alpaca_key(struct device *dev, int key, bool on);
-
-#endif
diff --git a/cdb_assist.c b/cdb_assist.c
index 549afbd..d62ef22 100644
--- a/cdb_assist.c
+++ b/cdb_assist.c
@@ -42,7 +42,7 @@
 #include <unistd.h>
 
 #include "cdba-server.h"
-#include "cdb_assist.h"
+#include "device.h"
 
 struct cdb_assist {
 	char serial[9];
@@ -89,6 +89,8 @@ enum {
 	STATE_num_num_m,
 };
 
+static void cdb_set_voltage(struct cdb_assist *cdb, unsigned mV);
+
 static void cdb_parser_bool(struct cdb_assist *cdb, const char *key, bool set)
 {
 	static const char *sz_keys[] = { "vbat", "btn1", "btn2", "btn3", "vbus" };
@@ -271,7 +273,7 @@ static int cdb_ctrl_write(struct cdb_assist *cdb, const char *buf, size_t len)
 	return write(cdb->control_tty, buf, len);
 }
 
-void *cdb_assist_open(struct device *dev)
+static void *cdb_assist_open(struct device *dev)
 {
 	struct cdb_assist *cdb;
 	int ret;
@@ -293,7 +295,7 @@ void *cdb_assist_open(struct device *dev)
 	return cdb;
 }
 
-void cdb_assist_close(struct device *dev)
+static void cdb_assist_close(struct device *dev)
 {
 	struct cdb_assist *cdb = dev->cdb;
 
@@ -309,14 +311,14 @@ static void cdb_power(struct cdb_assist *cdb, bool on)
 	cdb_ctrl_write(cdb, &cmd[on], 1);
 }
 
-void cdb_vbus(struct cdb_assist *cdb, bool on)
+static void cdb_vbus(struct cdb_assist *cdb, bool on)
 {
 	const char cmd[] = "vV";
 
 	cdb_ctrl_write(cdb, &cmd[on], 1);
 }
 
-int cdb_assist_power(struct device *dev, bool on)
+static int cdb_assist_power(struct device *dev, bool on)
 {
 	struct cdb_assist *cdb = dev->cdb;
 
@@ -325,23 +327,18 @@ int cdb_assist_power(struct device *dev, bool on)
 	return 0;
 }
 
-void cdb_assist_usb(struct device *dev, bool on)
+static void cdb_assist_usb(struct device *dev, bool on)
 {
 	cdb_vbus(dev->cdb, on);
 }
 
-void cdb_gpio(struct cdb_assist *cdb, int gpio, bool on)
+static void cdb_gpio(struct cdb_assist *cdb, int gpio, bool on)
 {
 	const char *cmd[] = { "aA", "bB", "cC" };
 	cdb_ctrl_write(cdb, &cmd[gpio][on], 1);
 }
 
-unsigned int cdb_vref(struct cdb_assist *cdb)
-{
-	return cdb->vref;
-}
-
-void cdb_assist_print_status(struct device *dev)
+static void cdb_assist_print_status(struct device *dev)
 {
 	struct cdb_assist *cdb = dev->cdb;
 	char buf[128];
@@ -360,7 +357,7 @@ void cdb_assist_print_status(struct device *dev)
 	cdba_send_buf(MSG_STATUS_UPDATE, n, buf);
 }
 
-void cdb_set_voltage(struct cdb_assist *cdb, unsigned mV)
+static void cdb_set_voltage(struct cdb_assist *cdb, unsigned mV)
 {
 	char buf[20];
 	int n;
@@ -369,7 +366,7 @@ void cdb_set_voltage(struct cdb_assist *cdb, unsigned mV)
 	cdb_ctrl_write(cdb, buf, n);
 }
 
-void cdb_assist_key(struct device *dev, int key, bool asserted)
+static void cdb_assist_key(struct device *dev, int key, bool asserted)
 {
 	struct cdb_assist *cdb = dev->cdb;
 
@@ -382,3 +379,12 @@ void cdb_assist_key(struct device *dev, int key, bool asserted)
 		break;
 	}
 }
+
+const struct control_ops cdb_assist_ops = {
+	.open = cdb_assist_open,
+	.close = cdb_assist_close,
+	.power = cdb_assist_power,
+	.print_status = cdb_assist_print_status,
+	.usb = cdb_assist_usb,
+	.key = cdb_assist_key,
+};
diff --git a/cdb_assist.h b/cdb_assist.h
deleted file mode 100644
index babcd65..0000000
--- a/cdb_assist.h
+++ /dev/null
@@ -1,23 +0,0 @@
-#ifndef __CDB_ASSIST_H__
-#define __CDB_ASSIST_H__
-
-#include <stdbool.h>
-
-#include "device.h"
-
-struct cdb_assist;
-
-void *cdb_assist_open(struct device *dev);
-void cdb_assist_close(struct device *dev);
-
-int cdb_assist_power(struct device *dev, bool on);
-void cdb_assist_usb(struct device *dev, bool on);
-void cdb_assist_key(struct device *dev, int key, bool asserted);
-void cdb_gpio(struct cdb_assist *cdb, int gpio, bool on);
-int cdb_target_write(struct device *dev, const void *buf, size_t len);
-void cdb_send_break(struct device *dev);
-unsigned int cdb_vref(struct cdb_assist *cdb);
-void cdb_assist_print_status(struct device *dev);
-void cdb_set_voltage(struct cdb_assist *cdb, unsigned mV);
-
-#endif
diff --git a/cdba-server.c b/cdba-server.c
index 5bd7a25..df6db01 100644
--- a/cdba-server.c
+++ b/cdba-server.c
@@ -406,6 +406,17 @@ int main(int argc, char **argv)
 
 done:
 
+	/* if we got here, stdin/out/err might be not accessible anymore */
+	ret = open("/dev/null", O_RDWR);
+	if (ret >= 0) {
+		close(STDIN_FILENO);
+		dup2(ret, STDIN_FILENO);
+		close(STDOUT_FILENO);
+		dup2(ret, STDOUT_FILENO);
+		close(STDERR_FILENO);
+		dup2(ret, STDERR_FILENO);
+	}
+
 	if (selected_device)
 		device_close(selected_device);
 
diff --git a/conmux.c b/conmux.c
index ef0e914..1cd8504 100644
--- a/conmux.c
+++ b/conmux.c
@@ -41,7 +41,7 @@
 #include <unistd.h>
 
 #include "cdba-server.h"
-#include "conmux.h"
+#include "device.h"
 
 extern int h_errno;
 
@@ -224,7 +224,7 @@ static int conmux_data(int fd, void *data)
 	return 0;
 }
 
-void *conmux_open(struct device *dev)
+static void *conmux_open(struct device *dev)
 {
 	struct addrinfo hints = {0}, *addrs, *addr;
 	struct conmux_response resp = {};
@@ -297,7 +297,7 @@ void *conmux_open(struct device *dev)
 	return conmux;
 }
 
-int conmux_power_on(struct device *dev)
+static int conmux_power_on(struct device *dev)
 {
 	struct conmux *conmux = dev->cdb;
 	char sz[] = "~$hardreset\n";
@@ -317,7 +317,7 @@ static int conmux_power_off(struct device *dev)
 	return write(conmux->fd, sz, sizeof(sz));
 }
 
-int conmux_power(struct device *dev, bool on)
+static int conmux_power(struct device *dev, bool on)
 {
 	if (on)
 		return conmux_power_on(dev);
@@ -325,9 +325,24 @@ int conmux_power(struct device *dev, bool on)
 		return conmux_power_off(dev);
 }
 
-int conmux_write(struct device *dev, const void *buf, size_t len)
+static int conmux_write(struct device *dev, const void *buf, size_t len)
 {
 	struct conmux *conmux = dev->cdb;
 
 	return write(conmux->fd, buf, len);
 }
+
+static void *conmux_console_open(struct device *dev)
+{
+	return dev->cdb;
+}
+
+const struct control_ops conmux_ops = {
+	.open = conmux_open,
+	.power = conmux_power,
+};
+
+const struct console_ops conmux_console_ops = {
+	.open = conmux_console_open,
+	.write = conmux_write,
+};
diff --git a/conmux.h b/conmux.h
deleted file mode 100644
index b23fa13..0000000
--- a/conmux.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef __CONMUX_H__
-#define __CONMUX_H__
-
-#include "device.h"
-
-struct conmux;
-
-void *conmux_open(struct device *dev);
-int conmux_power(struct device *dev, bool on);
-int conmux_write(struct device *dev, const void *buf, size_t len);
-
-#endif
diff --git a/console.c b/console.c
index 0a21523..d758c8b 100644
--- a/console.c
+++ b/console.c
@@ -32,11 +32,17 @@
 #include <sys/stat.h>
 
 #include <err.h>
+#include <stdlib.h>
 #include <unistd.h>
 
 #include "cdba-server.h"
 #include "device.h"
 
+struct console {
+	int console_fd;
+	struct termios console_tios;
+};
+
 static int console_data(int fd, void *data)
 {
 	char buf[128];
@@ -51,21 +57,36 @@ static int console_data(int fd, void *data)
 	return 0;
 }
 
-void console_open(struct device *device)
+static void *console_open(struct device *device)
 {
-	device->console_fd = tty_open(device->console_dev, &device->console_tios);
-	if (device->console_fd < 0)
+	struct console *console;
+
+	console = calloc(1, sizeof(*console));
+	console->console_fd = tty_open(device->console_dev, &console->console_tios);
+	if (console->console_fd < 0)
 		err(1, "failed to open %s", device->console_dev);
 
-	watch_add_readfd(device->console_fd, console_data, device);
+	watch_add_readfd(console->console_fd, console_data, device);
+
+	return console;
 }
 
-int console_write(struct device *device, const void *buf, size_t len)
+static int console_write(struct device *device, const void *buf, size_t len)
 {
-	return write(device->console_fd, buf, len);;
+	struct console *console = device->console;
+
+	return write(console->console_fd, buf, len);;
 }
 
-void console_send_break(struct device *device)
+static void console_send_break(struct device *device)
 {
-	tcsendbreak(device->console_fd, 0);
+	struct console *console = device->console;
+
+	tcsendbreak(console->console_fd, 0);
 }
+
+const struct console_ops console_ops = {
+	.open = console_open,
+	.write = console_write,
+	.send_break = console_send_break,
+};
diff --git a/console.h b/console.h
deleted file mode 100644
index 62258a2..0000000
--- a/console.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifndef __CONSOLE_H__
-#define __CONSOLE_H__
-
-#include "device.h"
-
-void console_open(struct device *device);
-int console_write(struct device *device, const void *buf, size_t len);
-void console_send_break(struct device *device);
-
-#endif
diff --git a/device.c b/device.c
index 826b038..01f369c 100644
--- a/device.c
+++ b/device.c
@@ -43,12 +43,23 @@
 #include "cdba-server.h"
 #include "device.h"
 #include "fastboot.h"
-#include "console.h"
 #include "list.h"
 #include "ppps.h"
 
 #define ARRAY_SIZE(x) ((sizeof(x)/sizeof((x)[0])))
 
+#define device_has_control(_dev, _op) \
+	((_dev)->control_ops && (_dev)->control_ops->_op)
+
+#define device_control(_dev, _op, ...) \
+	(_dev)->control_ops->_op((_dev) , ## __VA_ARGS__)
+
+#define device_has_console(_dev, _op) \
+	((_dev)->console_ops && (_dev)->console_ops->_op)
+
+#define device_console(_dev, _op, ...) \
+	(_dev)->console_ops->_op((_dev) , ## __VA_ARGS__)
+
 static struct list_head devices = LIST_INIT(devices);
 
 void device_add(struct device *device)
@@ -118,21 +129,24 @@ struct device *device_open(const char *board,
 	return NULL;
 
 found:
-	assert(device->open || device->console_dev);
-
 	if (!device_check_access(device, username))
 		return NULL;
 
+	assert(device->console_ops);
+	assert(device->console_ops->open);
+	assert(device->console_ops->write);
+
 	device_lock(device);
 
-	if (device->open) {
-		device->cdb = device->open(device);
+	if (device_has_control(device, open)) {
+		device->cdb = device_control(device, open);
 		if (!device->cdb)
 			errx(1, "failed to open device controller");
 	}
 
-	if (device->console_dev)
-		console_open(device);
+	device->console = device_console(device, open);
+	if (!device->console)
+		errx(1, "failed to open device console");
 
 	if (device->usb_always_on)
 		device_usb(device, true);
@@ -144,13 +158,13 @@ found:
 
 static void device_impl_power(struct device *device, bool on)
 {
-	device->power(device, on);
+	device_control(device, power, on);
 }
 
 static void device_key(struct device *device, int key, bool asserted)
 {
-	if (device->key)
-		device->key(device, key, asserted);
+	if (device_has_control(device, key))
+		device_control(device, key, key, asserted);
 }
 
 enum {
@@ -219,7 +233,7 @@ static void device_tick(void *data)
 
 static int device_power_on(struct device *device)
 {
-	if (!device || !device->power)
+	if (!device || !device_has_control(device, power))
 		return 0;
 
 	device->state = DEVICE_STATE_START;
@@ -230,10 +244,10 @@ static int device_power_on(struct device *device)
 
 static int device_power_off(struct device *device)
 {
-	if (!device || !device->power)
+	if (!device || !device_has_control(device, power))
 		return 0;
 
-	device->power(device, false);
+	device_control(device, power, false);
 
 	return 0;
 }
@@ -248,18 +262,16 @@ int device_power(struct device *device, bool on)
 
 void device_print_status(struct device *device)
 {
-	if (device->print_status)
-		device->print_status(device);
+	if (device_has_control(device, print_status))
+		device_control(device, print_status);
 }
 
 void device_usb(struct device *device, bool on)
 {
-	if (device->usb) {
-		if (device->ppps_path)
-			ppps_power(device, on);
-		else
-			device->usb(device, on);
-	}
+	if (device->ppps_path)
+		ppps_power(device, on);
+	else if (device_has_control(device, usb))
+		device_control(device, usb, on);
 }
 
 int device_write(struct device *device, const void *buf, size_t len)
@@ -267,9 +279,7 @@ int device_write(struct device *device, const void *buf, size_t len)
 	if (!device)
 		return 0;
 
-	assert(device->write);
-
-	return device->write(device, buf, len);
+	return device_console(device, write, buf, len);
 }
 
 void device_fastboot_boot(struct device *device)
@@ -294,8 +304,8 @@ void device_boot(struct device *device, const void *data, size_t len)
 
 void device_send_break(struct device *device)
 {
-	if (device->send_break)
-		device->send_break(device);
+	if (device_has_console(device, send_break))
+		device_console(device, send_break);
 }
 
 void device_list_devices(const char *username)
@@ -348,6 +358,6 @@ void device_close(struct device *dev)
 		device_usb(dev, false);
 	device_power(dev, false);
 
-	if (dev->close)
-		dev->close(dev);
+	if (device_has_control(dev, close))
+		device_control(dev, close);
 }
diff --git a/device.h b/device.h
index 0ee659b..b41e66a 100644
--- a/device.h
+++ b/device.h
@@ -7,6 +7,23 @@
 struct cdb_assist;
 struct fastboot;
 struct fastboot_ops;
+struct device;
+
+struct control_ops {
+	void *(*open)(struct device *dev);
+	void (*close)(struct device *dev);
+	int (*power)(struct device *dev, bool on);
+	void (*usb)(struct device *dev, bool on);
+	void (*key)(struct device *device, int key, bool asserted);
+	void (*print_status)(struct device *dev);
+};
+
+struct console_ops {
+	void *(*open)(struct device *dev);
+	int (*write)(struct device *dev, const void *buf, size_t len);
+
+	void (*send_break)(struct device *dev);
+};
 
 struct device {
 	char *board;
@@ -27,22 +44,13 @@ struct device {
 
 	void (*boot)(struct device *);
 
-	void *(*open)(struct device *dev);
-	void (*close)(struct device *dev);
-	int (*power)(struct device *dev, bool on);
-	void (*usb)(struct device *dev, bool on);
-	void (*print_status)(struct device *dev);
-	int (*write)(struct device *dev, const void *buf, size_t len);
-	void (*fastboot_key)(struct device *dev, bool on);
-	void (*key)(struct device *device, int key, bool asserted);
+	const struct control_ops *control_ops;
+	const struct console_ops *console_ops;
 
-	void (*send_break)(struct device *dev);
 	const char *set_active;
 
 	void *cdb;
-
-	int console_fd;
-	struct termios console_tios;
+	void *console;
 
 	struct list_head node;
 };
@@ -78,4 +86,14 @@ enum {
 	DEVICE_KEY_POWER,
 };
 
+extern const struct control_ops alpaca_ops;
+extern const struct control_ops cdb_assist_ops;
+extern const struct control_ops conmux_ops;
+extern const struct control_ops ftdi_gpio_ops;
+extern const struct control_ops external_ops;
+extern const struct control_ops qcomlt_dbg_ops;
+
+extern const struct console_ops conmux_console_ops;
+extern const struct console_ops console_ops;
+
 #endif
diff --git a/device_parser.c b/device_parser.c
index bab9a1b..d9f2800 100644
--- a/device_parser.c
+++ b/device_parser.c
@@ -33,13 +33,6 @@
 #include <yaml.h>
 
 #include "device.h"
-#include "alpaca.h"
-#include "ftdi-gpio.h"
-#include "cdb_assist.h"
-#include "conmux.h"
-#include "console.h"
-#include "qcomlt_dbg.h"
-#include "ppps.h"
 
 #define TOKEN_LENGTH	16384
 
@@ -82,6 +75,26 @@ static bool expect(struct device_parser *dp, int type, char *scalar)
 	exit(1);
 }
 
+static void set_control_ops(struct device *dev, const struct control_ops *ops)
+{
+	if (dev->control_ops) {
+		fprintf(stderr, "device parser: control operations are already selected for %s\n", dev->name);
+		exit(1);
+	}
+
+	dev->control_ops = ops;
+}
+
+static void set_console_ops(struct device *dev, const struct console_ops *ops)
+{
+	if (dev->console_ops) {
+		fprintf(stderr, "device parser: console operations are already selected for %s\n", dev->name);
+		exit(1);
+	}
+
+	dev->console_ops = ops;
+}
+
 static void parse_board(struct device_parser *dp)
 {
 	struct device *dev;
@@ -121,44 +134,28 @@ static void parse_board(struct device_parser *dp)
 			dev->name = strdup(value);
 		} else if (!strcmp(key, "cdba")) {
 			dev->control_dev = strdup(value);
-
-			dev->open = cdb_assist_open;
-			dev->close = cdb_assist_close;
-			dev->power = cdb_assist_power;
-			dev->print_status = cdb_assist_print_status;
-			dev->usb = cdb_assist_usb;
-			dev->key = cdb_assist_key;
+			set_control_ops(dev, &cdb_assist_ops);
 		} else if (!strcmp(key, "conmux")) {
+			/* conmux handles both control and console */
 			dev->control_dev = strdup(value);
-
-			dev->open = conmux_open;
-			dev->power = conmux_power;
-			dev->write = conmux_write;
+			dev->console_dev = strdup(value);
+			set_control_ops(dev, &conmux_ops);
+			set_console_ops(dev, &conmux_console_ops);
 		} else if (!strcmp(key, "alpaca")) {
 			dev->control_dev = strdup(value);
-
-			dev->open = alpaca_open;
-			dev->power = alpaca_power;
-			dev->usb = alpaca_usb;
-			dev->key = alpaca_key;
+			set_control_ops(dev, &alpaca_ops);
 		} else if (!strcmp(key, "ftdi_gpio")) {
 			dev->control_dev = strdup(value);
-
-			dev->open = ftdi_gpio_open;
-			dev->power = ftdi_gpio_power;
-			dev->usb = ftdi_gpio_usb;
-			dev->key = ftdi_gpio_key;
+			set_control_ops(dev, &ftdi_gpio_ops);
+		} else if (!strcmp(key, "external")) {
+			dev->control_dev = strdup(value);
+			set_control_ops(dev, &external_ops);
 		} else if (!strcmp(key, "qcomlt_debug_board")) {
 			dev->control_dev = strdup(value);
-
-			dev->open = qcomlt_dbg_open;
-			dev->power = qcomlt_dbg_power;
-			dev->usb = qcomlt_dbg_usb;
-			dev->key = qcomlt_dbg_key;
+			set_control_ops(dev, &qcomlt_dbg_ops);
 		} else if (!strcmp(key, "console")) {
 			dev->console_dev = strdup(value);
-			dev->write = console_write;
-			dev->send_break = console_send_break;
+			set_console_ops(dev, &console_ops);
 		} else if (!strcmp(key, "voltage")) {
 			dev->voltage = strtoul(value, NULL, 10);
 		} else if (!strcmp(key, "fastboot")) {
@@ -188,7 +185,7 @@ static void parse_board(struct device_parser *dp)
 		}
 	}
 
-	if (!dev->board || !dev->serial || !(dev->open || dev->console_dev)) {
+	if (!dev->board || !dev->serial || !dev->console_dev) {
 		fprintf(stderr, "device parser: insufficiently defined device\n");
 		exit(1);
 	}
diff --git a/external.c b/external.c
new file mode 100644
index 0000000..0fb82e1
--- /dev/null
+++ b/external.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2021-2023, Linaro Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 3. Neither the name of the copyright holder 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 <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <errno.h>
+#include <stdlib.h>
+
+#include "cdba-server.h"
+#include "device.h"
+
+struct external {
+	const char *path;
+	const char *board;
+};
+
+static int external_helper(struct external *ext, const char *command, bool on)
+{
+	pid_t pid, pid_ret;
+	int status;
+
+	pid =  fork();
+	switch (pid) {
+	case 0:
+		/* Do not clobber stdout with program messages or cdba will become confused */
+		dup2(2, 1);
+		return execlp(ext->path, ext->path, ext->board, command, on ? "on": "off", NULL);
+	case -1:
+		return -1;
+	default:
+		break;
+	}
+
+	pid_ret = waitpid(pid, &status, 0);
+	if (pid_ret < 0)
+		return pid_ret;
+
+	if (WIFEXITED(status))
+		return WEXITSTATUS(status);
+	else if (WIFSIGNALED(status))
+		errno = -EINTR;
+	else
+		errno = -EIO;
+
+	return -1;
+}
+
+static void *external_open(struct device *dev)
+{
+	struct external *ext;
+
+	dev->has_power_key = true;
+
+	ext = calloc(1, sizeof(*ext));
+
+	ext->path = dev->control_dev;
+	ext->board = dev->board;
+
+	return ext;
+}
+
+static int external_power(struct device *dev, bool on)
+{
+	struct external *ext = dev->cdb;
+
+	return external_helper(ext, "power", on);
+}
+
+static void external_usb(struct device *dev, bool on)
+{
+	struct external *ext = dev->cdb;
+
+	external_helper(ext, "usb", on);
+}
+
+static void external_key(struct device *dev, int key, bool asserted)
+{
+	struct external *ext = dev->cdb;
+
+	switch (key) {
+	case DEVICE_KEY_FASTBOOT:
+		external_helper(ext, "key-fastboot", asserted);
+		break;
+	case DEVICE_KEY_POWER:
+		external_helper(ext, "key-power", asserted);
+		break;
+	}
+}
+
+const struct control_ops external_ops = {
+	.open = external_open,
+	.power = external_power,
+	.usb = external_usb,
+	.key = external_key,
+};
diff --git a/ftdi-gpio.c b/ftdi-gpio.c
index 3f37856..dcac871 100644
--- a/ftdi-gpio.c
+++ b/ftdi-gpio.c
@@ -41,7 +41,7 @@
 #include <unistd.h>
 
 #include "cdba-server.h"
-#include "ftdi-gpio.h"
+#include "device.h"
 
 #include <ftdi.h>
 
@@ -159,7 +159,7 @@ static void ftdi_gpio_parse_config(struct ftdi_gpio *ftdi_gpio, char *control_de
 	}
 }
 
-void *ftdi_gpio_open(struct device *dev)
+static void *ftdi_gpio_open(struct device *dev)
 {
 	struct ftdi_gpio *ftdi_gpio;
 	int ret;
@@ -224,21 +224,21 @@ static void ftdi_gpio_device_usb(struct ftdi_gpio *ftdi_gpio, bool on)
 	ftdi_gpio_toggle_io(ftdi_gpio, GPIO_USB_DISCONNECT, on);
 }
 
-int ftdi_gpio_power(struct device *dev, bool on)
+static int ftdi_gpio_power(struct device *dev, bool on)
 {
 	struct ftdi_gpio *ftdi_gpio = dev->cdb;
 
 	return ftdi_gpio_device_power(ftdi_gpio, on);
 }
 
-void ftdi_gpio_usb(struct device *dev, bool on)
+static void ftdi_gpio_usb(struct device *dev, bool on)
 {
 	struct ftdi_gpio *ftdi_gpio = dev->cdb;
 
 	ftdi_gpio_device_usb(ftdi_gpio, on);
 }
 
-void ftdi_gpio_key(struct device *dev, int key, bool asserted)
+static void ftdi_gpio_key(struct device *dev, int key, bool asserted)
 {
 	struct ftdi_gpio *ftdi_gpio = dev->cdb;
 
@@ -251,3 +251,10 @@ void ftdi_gpio_key(struct device *dev, int key, bool asserted)
 		break;
 	}
 }
+
+const struct control_ops ftdi_gpio_ops = {
+	.open = ftdi_gpio_open,
+	.power = ftdi_gpio_power,
+	.usb = ftdi_gpio_usb,
+	.key = ftdi_gpio_key,
+};
diff --git a/ftdi-gpio.h b/ftdi-gpio.h
deleted file mode 100644
index a705d28..0000000
--- a/ftdi-gpio.h
+++ /dev/null
@@ -1,13 +0,0 @@
-#ifndef __FTDI_GPIO_H__
-#define __FTDI_GPIO_H__
-
-#include "device.h"
-
-struct ftdi_gpio;
-
-void *ftdi_gpio_open(struct device *dev);
-int ftdi_gpio_power(struct device *dev, bool on);
-void ftdi_gpio_usb(struct device *dev, bool on);
-void ftdi_gpio_key(struct device *dev, int key, bool on);
-
-#endif
diff --git a/meson.build b/meson.build
index 0392b0e..15254b6 100644
--- a/meson.build
+++ b/meson.build
@@ -61,6 +61,7 @@ server_srcs = ['cdba-server.c',
 	       'conmux.c',
 	       'device.c',
 	       'device_parser.c',
+               'external.c',
 	       'fastboot.c',
 	       'alpaca.c',
 	       'ftdi-gpio.c',
diff --git a/qcomlt_dbg.c b/qcomlt_dbg.c
index 92d04a8..bda7e61 100644
--- a/qcomlt_dbg.c
+++ b/qcomlt_dbg.c
@@ -43,14 +43,14 @@
 #include <unistd.h>
 
 #include "cdba-server.h"
-#include "qcomlt_dbg.h"
+#include "device.h"
 
 struct qcomlt_dbg {
 	int fd;
 	struct termios orig_tios;
 };
 
-void *qcomlt_dbg_open(struct device *dev)
+static void *qcomlt_dbg_open(struct device *dev)
 {
 	struct qcomlt_dbg *dbg;
 
@@ -68,7 +68,7 @@ void *qcomlt_dbg_open(struct device *dev)
 	return dbg;
 }
 
-int qcomlt_dbg_power(struct device *dev, bool on)
+static int qcomlt_dbg_power(struct device *dev, bool on)
 {
 	struct qcomlt_dbg *dbg = dev->cdb;	
 
@@ -76,7 +76,7 @@ int qcomlt_dbg_power(struct device *dev, bool on)
 	return write(dbg->fd, &("pP"[on]), 1);
 }
 
-void qcomlt_dbg_usb(struct device *dev, bool on)
+static void qcomlt_dbg_usb(struct device *dev, bool on)
 {
 	struct qcomlt_dbg *dbg = dev->cdb;	
 
@@ -84,7 +84,7 @@ void qcomlt_dbg_usb(struct device *dev, bool on)
 	write(dbg->fd, &("uU"[on]), 1);
 }
 
-void qcomlt_dbg_key(struct device *dev, int key, bool asserted)
+static void qcomlt_dbg_key(struct device *dev, int key, bool asserted)
 {
 	struct qcomlt_dbg *dbg = dev->cdb;	
 
@@ -99,3 +99,10 @@ void qcomlt_dbg_key(struct device *dev, int key, bool asserted)
 		break;
 	}
 }
+
+const struct control_ops qcomlt_dbg_ops = {
+	.open = qcomlt_dbg_open,
+	.power = qcomlt_dbg_power,
+	.usb = qcomlt_dbg_usb,
+	.key = qcomlt_dbg_key,
+};
diff --git a/qcomlt_dbg.h b/qcomlt_dbg.h
deleted file mode 100644
index 1fc976e..0000000
--- a/qcomlt_dbg.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef __QCOMLT_DBG_H__
-#define __QCOMLT_DBG_H__
-
-#include "device.h"
-
-void *qcomlt_dbg_open(struct device *dev);
-int qcomlt_dbg_power(struct device *dev, bool on);
-void qcomlt_dbg_usb(struct device *dev, bool on);
-void qcomlt_dbg_key(struct device *dev, int key, bool asserted);
-
-#endif