diff --git a/firmware/application/m4_startup.cpp b/firmware/application/m4_startup.cpp
index 6dc74b4b..6b9df47b 100644
--- a/firmware/application/m4_startup.cpp
+++ b/firmware/application/m4_startup.cpp
@@ -23,6 +23,9 @@
 
 #include "hal.h"
 
+#include "message.hpp"
+#include "portapack_shared_memory.hpp"
+
 #include <cstring>
 
 /* TODO: OK, this is cool, but how do I put the M4 to sleep so I can switch to
@@ -44,3 +47,8 @@ void m4_init(const portapack::spi_flash::region_t from, const portapack::memory:
 	/* Reset M4 core */
 	LPC_RGU->RESET_CTRL[0] = (1 << 13);
 }
+
+void m4_request_shutdown() {
+	ShutdownMessage shutdown_message;
+	shared_memory.baseband_queue.push(shutdown_message);
+}
diff --git a/firmware/application/m4_startup.hpp b/firmware/application/m4_startup.hpp
index 16758d90..ce22770e 100644
--- a/firmware/application/m4_startup.hpp
+++ b/firmware/application/m4_startup.hpp
@@ -28,5 +28,6 @@
 #include "spi_image.hpp"
 
 void m4_init(const portapack::spi_flash::region_t from, const portapack::memory::region_t to);
+void m4_request_shutdown();
 
 #endif/*__M4_STARTUP_H__*/
diff --git a/firmware/application/main.cpp b/firmware/application/main.cpp
index 3a6e4d11..9669b715 100755
--- a/firmware/application/main.cpp
+++ b/firmware/application/main.cpp
@@ -252,6 +252,13 @@ int main(void) {
 	ui::Painter painter;
 	EventDispatcher event_dispatcher { &system_view, painter, context };
 
+	auto& message_handlers = context.message_map;
+	message_handlers.register_handler(Message::ID::Shutdown,
+		[&event_dispatcher](const Message* const) {
+			event_dispatcher.request_stop();
+		}
+	);
+
 	m4_init(portapack::spi_flash::baseband, portapack::memory::map::m4_code);
 
 	controls_init();
@@ -261,5 +268,7 @@ int main(void) {
 
 	event_dispatcher.run();
 
+	portapack::shutdown();
+	m4_init(portapack::spi_flash::hackrf, portapack::memory::map::m4_code_hackrf);	
 	return 0;
 }
diff --git a/firmware/application/portapack.cpp b/firmware/application/portapack.cpp
index 9f4c361c..8f60e064 100644
--- a/firmware/application/portapack.cpp
+++ b/firmware/application/portapack.cpp
@@ -153,6 +153,9 @@ void shutdown() {
 	// TODO: Wait a bit for supplies to discharge?
 
 	chSysDisable();
+
+	systick_stop();
+
 	hackrf::one::reset();
 }
 
diff --git a/firmware/application/ui_navigation.cpp b/firmware/application/ui_navigation.cpp
index 2b2f9830..3096cfc2 100644
--- a/firmware/application/ui_navigation.cpp
+++ b/firmware/application/ui_navigation.cpp
@@ -27,10 +27,7 @@
 #include "ui_debug.hpp"
 #include "ui_receiver.hpp"
 
-#include "portapack.hpp"
 #include "m4_startup.hpp"
-#include "spi_image.hpp"
-using namespace portapack;
 
 namespace ui {
 
@@ -149,13 +146,7 @@ Context& SystemView::context() const {
 
 HackRFFirmwareView::HackRFFirmwareView(NavigationView& nav) {
 	button_yes.on_select = [&nav](Button&){
-		shutdown();
-
-		m4_init(spi_flash::hackrf, memory::map::m4_code_hackrf);
-
-		while(true) {
-			__WFE();
-		}
+		m4_request_shutdown();
 	};
 
 	button_no.on_select = [&nav](Button&){
diff --git a/firmware/baseband/main.cpp b/firmware/baseband/main.cpp
index f92d5f9f..72a13e0b 100755
--- a/firmware/baseband/main.cpp
+++ b/firmware/baseband/main.cpp
@@ -776,6 +776,10 @@ static void m0apptxevent_interrupt_enable() {
 	nvicEnableVector(M0CORE_IRQn, CORTEX_PRIORITY_MASK(LPC43XX_M0APPTXEVENT_IRQ_PRIORITY));
 }
 
+static void m0apptxevent_interrupt_disable() {
+	nvicDisableVector(M0CORE_IRQn);
+}
+
 extern "C" {
 
 CH_IRQ_HANDLER(MAPP_IRQHandler) {
@@ -792,6 +796,18 @@ CH_IRQ_HANDLER(MAPP_IRQHandler) {
 
 }
 
+static void shutdown() {
+	// TODO: Is this complete?
+	
+	nvicDisableVector(DMA_IRQn);
+
+	m0apptxevent_interrupt_disable();
+	
+	chSysDisable();
+
+	systick_stop();
+}
+
 static constexpr auto direction = baseband::Direction::Receive;
 
 int main(void) {
@@ -849,6 +865,12 @@ int main(void) {
 		}
 	);
 
+	message_handlers.register_handler(Message::ID::Shutdown,
+		[&event_dispatcher](const Message* const) {
+			event_dispatcher.request_stop();
+		}
+	);
+
 	/* TODO: Ensure DMAs are configured to point at first LLI in chain. */
 
 	if( direction == baseband::Direction::Receive ) {
@@ -868,5 +890,10 @@ int main(void) {
 
 	event_dispatcher.run();
 
+	shutdown();
+
+	ShutdownMessage shutdown_message;
+	shared_memory.application_queue.push(shutdown_message);
+
 	return 0;
 }
diff --git a/firmware/common/message.hpp b/firmware/common/message.hpp
index 72f73369..fa06c703 100644
--- a/firmware/common/message.hpp
+++ b/firmware/common/message.hpp
@@ -43,7 +43,7 @@ public:
 		BasebandConfiguration = 5,
 		FSKConfiguration = 6,
 		FSKPacket = 7,
-		TestResults = 8,
+		Shutdown = 8,
 		MAX
 	};
 
@@ -233,6 +233,14 @@ public:
 	FSKPacket packet;
 };
 
+class ShutdownMessage : public Message {
+public:
+	constexpr ShutdownMessage(
+	) : Message { ID::Shutdown }
+	{
+	}
+};
+
 class MessageHandlerMap {
 public:
 	using MessageHandler = std::function<void(const Message* const p)>;