diff --git a/source/platform/virtual/alarm.c b/source/platform/virtual/alarm.c
new file mode 100644
index 0000000..410bf8f
--- /dev/null
+++ b/source/platform/virtual/alarm.c
@@ -0,0 +1,64 @@
+/*
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/stm32/exti.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/rtc.h>
+*/
+
+#include <rtc.h>
+
+static int reset = 0;
+
+void rtc_alarm_isr(void)
+{
+    /*
+	if (rtc_check_flag(RTC_ALR)) {
+		rtc_clear_flag(RTC_ALR);
+
+		rtc_disable_alarm();
+		exti_reset_request(EXTI17);
+
+		if (!reset) {
+			reset = 1;
+			gpio_set(GPIOA, GPIO1);
+
+			rtc_set_alarm_time(rtc_get_counter_val() + 5);
+			rtc_enable_alarm();
+		} else {
+			reset = 0;
+			gpio_set(GPIOA, GPIO1);
+			alarm_disable();
+		}
+	}
+    */
+}
+
+int alarm_enable(uint32_t timeout)
+{
+    /*
+	rtc_enable_alarm();
+	rtc_set_alarm_time(rtc_get_counter_val() + timeout);
+
+	exti_enable_request(EXTI17);
+	exti_set_trigger(EXTI17, EXTI_TRIGGER_RISING);
+
+	nvic_enable_irq(NVIC_RTC_ALARM_IRQ);
+	nvic_set_priority(NVIC_RTC_ALARM_IRQ, 1);
+
+	rtc_interrupt_enable(RTC_ALR);
+    */
+
+	return 0;
+}
+
+int alarm_disable(void)
+{
+    /*
+	exti_disable_request(EXTI17);
+	nvic_disable_irq(NVIC_RTC_ALARM_IRQ);
+	rtc_interrupt_disable(RTC_ALR);
+	rtc_disable_alarm();
+    */
+
+	return 0;
+}
diff --git a/source/platform/virtual/buzzer.c b/source/platform/virtual/buzzer.c
new file mode 100644
index 0000000..4eca31f
--- /dev/null
+++ b/source/platform/virtual/buzzer.c
@@ -0,0 +1,61 @@
+/*
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/timer.h>
+*/
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <buzzer.h>
+#include <macros.h>
+
+struct buzzer buzzers[] = {
+	{ },
+};
+
+size_t nbuzzers = count_of(buzzers);
+
+void buzzer_init(struct buzzer *buzzer)
+{
+    /*
+	rcc_periph_reset_pulse(buzzer->timer);
+
+	timer_set_mode(buzzer->timer, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE,
+		TIM_CR1_DIR_UP);
+
+	timer_set_prescaler(buzzer->timer, 72);
+	timer_set_repetition_counter(buzzer->timer, 0);
+	timer_enable_preload(buzzer->timer);
+	timer_enable_break_main_output(buzzer->timer);
+	timer_continuous_mode(buzzer->timer);
+
+	timer_disable_oc_output(buzzer->timer, buzzer->channel);
+	timer_set_oc_mode(buzzer->timer, buzzer->channel, TIM_OCM_PWM1);
+	timer_set_oc_value(buzzer->timer, buzzer->channel, 0);
+	timer_enable_oc_output(buzzer->timer, buzzer->channel);
+    */
+}
+
+void buzzer_enable(struct buzzer *buzzer)
+{
+    /*
+	timer_enable_counter(buzzer->timer);
+    */
+}
+
+void buzzer_disable(struct buzzer *buzzer)
+{
+    /*
+	timer_disable_counter(buzzer->timer);
+    */
+}
+
+void buzzer_set_freq(struct buzzer *buzzer, uint32_t freq)
+{
+    /*
+	uint32_t period = 1000000 / freq;
+
+	timer_set_period(buzzer->timer, period);
+	timer_set_oc_value(buzzer->timer, buzzer->channel, period / 2);
+    */
+}
diff --git a/source/platform/virtual/gpio.c b/source/platform/virtual/gpio.c
new file mode 100644
index 0000000..da9aeb6
--- /dev/null
+++ b/source/platform/virtual/gpio.c
@@ -0,0 +1,53 @@
+/*
+#include <libopencm3/stm32/gpio.h>
+*/
+
+#include <gpio.h>
+
+int gpio_init(void)
+{
+#if 0
+	/* Set up GPIOs for SPI 1 */
+	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_PUSHPULL, GPIO_SPI1_NSS);
+	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_SPI1_SCK |
+		GPIO_SPI1_MOSI);
+	gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT,
+		GPIO_SPI1_MISO);
+
+	/* Set up GPIOs for user console (USART 1) */
+	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
+	gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
+		GPIO_CNF_INPUT_FLOAT, GPIO_USART1_RX);
+
+	/* Set up GPIOs for admin console (USART 2) */
+	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
+	gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
+		GPIO_CNF_INPUT_FLOAT, GPIO_USART2_RX);
+
+	/* Set up GPIOs for reset. */
+	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN,
+		GPIO1);
+
+	/* Set up GPIOs for timers. */
+	gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON,
+		AFIO_MAPR_TIM2_REMAP_PARTIAL_REMAP1);
+	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
+		GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_TIM2_PR1_CH1_ETR);
+
+	/* Set up GPIO for LED. */
+	gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO0);
+	gpio_clear(GPIOB, GPIO0);
+	gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO10);
+	gpio_set(GPIOC, GPIO10);
+#endif
+
+	return 0;
+}
+
+void gpio_cleanup(void)
+{
+}
diff --git a/source/platform/virtual/led.c b/source/platform/virtual/led.c
new file mode 100644
index 0000000..ea74bee
--- /dev/null
+++ b/source/platform/virtual/led.c
@@ -0,0 +1,40 @@
+/*
+#include <libopencm3/stm32/gpio.h>
+*/
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <led.h>
+#include <macros.h>
+
+struct led leds[] = {
+	{ },
+};
+
+size_t nleds = count_of(leds);
+
+void led_enable(struct led *led)
+{
+    /*
+	if (!led)
+		return;
+
+	if (led->invert)
+		gpio_clear(led->port, led->pin);
+	else
+		gpio_set(led->port, led->pin);
+        */
+}
+
+void led_disable(struct led *led)
+{
+    /*
+	if (!led)
+		return;
+
+	if (led->invert)
+		gpio_set(led->port, led->pin);
+	else
+		gpio_clear(led->port, led->pin);
+        */
+}
diff --git a/source/platform/virtual/rcc.c b/source/platform/virtual/rcc.c
new file mode 100644
index 0000000..d239915
--- /dev/null
+++ b/source/platform/virtual/rcc.c
@@ -0,0 +1,25 @@
+/*
+#include <libopencm3/stm32/rcc.h>
+*/
+
+#include <rcc.h>
+
+int rcc_init(void)
+{
+    /*
+	rcc_periph_clock_enable(RCC_AFIO);
+	rcc_periph_clock_enable(RCC_GPIOA);
+	rcc_periph_clock_enable(RCC_GPIOB);
+	rcc_periph_clock_enable(RCC_GPIOC);
+	rcc_periph_clock_enable(RCC_SPI1);
+	rcc_periph_clock_enable(RCC_USART1);
+	rcc_periph_clock_enable(RCC_USART2);
+	rcc_periph_clock_enable(RCC_TIM2);
+    */
+
+	return 0;
+}
+
+void rcc_cleanup(void)
+{
+}
diff --git a/source/platform/virtual/rtc.c b/source/platform/virtual/rtc.c
new file mode 100644
index 0000000..e264b8e
--- /dev/null
+++ b/source/platform/virtual/rtc.c
@@ -0,0 +1,22 @@
+#include <macros.h>
+#include <rtc.h>
+
+int rtc_get_time(struct tm *time)
+{
+	return 0;
+}
+
+static int rtc_set_time(struct tm *time)
+{
+
+	return 0;
+}
+
+int rtc_init(struct tm *time)
+{
+    /*
+	rtc_set_time(time);
+    */
+
+	return 0;
+}
diff --git a/source/platform/virtual/spi.c b/source/platform/virtual/spi.c
new file mode 100644
index 0000000..13ae1db
--- /dev/null
+++ b/source/platform/virtual/spi.c
@@ -0,0 +1,45 @@
+#define _GNU_SOURCE
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <spi.h>
+
+static int virtual_spi_tx_rx(struct spi_dev *dev, void *rx_buf, size_t rx_len,
+	const void *tx_buf, size_t tx_len);
+
+static struct spi_ops virtual_spi_ops = {
+	.tx_rx = virtual_spi_tx_rx,
+};
+
+static void virtual_spi_init(void)
+{
+    /* TODO */
+}
+
+struct spi_dev *spi_probe(void)
+{
+	struct spi_dev *dev;
+
+	if (!(dev = malloc(sizeof *dev)))
+		return NULL;
+
+	dev->ops = &virtual_spi_ops;
+    /*
+	dev->dev_id = SPI1;
+
+    */
+	virtual_spi_init();
+
+	return dev;
+}
+
+void spi_release(struct spi_dev *dev)
+{
+	free(dev);
+}
+
+static int virtual_spi_tx_rx(struct spi_dev *dev, void *rx_buf, size_t rx_len,
+	const void *tx_buf, size_t tx_len)
+{
+	return 0;
+}