diff --git a/Makefile b/Makefile
index beb889e4e8702ef63f284dd65b82a898454d3f63..b589275757e2eaecf30215a1f3b37660176636d6 100644
--- a/Makefile
+++ b/Makefile
@@ -121,9 +121,11 @@ LDSCRIPT= $(STARTUPLD)/STM32F411xE.ld
# C sources that can be compiled in ARM or THUMB mode depending on the global
# setting.
-CSRC = $(ALLCSRC) \
- $(SRCDIR)/crc32.c \
- $(SRCDIR)/main.c
+CSRC = $(ALLCSRC) \
+ $(SRCDIR)/crc32.c \
+ $(SRCDIR)/main.c \
+ $(SRCDIR)/serial.c \
+ $(SRCDIR)/usb.c
# C++ sources that can be compiled in ARM or THUMB mode depending on the global
# setting.
diff --git a/cfg/halconf.h b/cfg/halconf.h
index ddb46c0da9da2a2878d77bffe34dd217a7de5a22..fb8be9548eb031b5f212a48e5fb67f09de089276 100644
--- a/cfg/halconf.h
+++ b/cfg/halconf.h
@@ -142,14 +142,14 @@
* @brief Enables the SERIAL subsystem.
*/
#if !defined(HAL_USE_SERIAL) || defined(__DOXYGEN__)
-#define HAL_USE_SERIAL TRUE
+#define HAL_USE_SERIAL FALSE
#endif
/**
* @brief Enables the SERIAL over USB subsystem.
*/
#if !defined(HAL_USE_SERIAL_USB) || defined(__DOXYGEN__)
-#define HAL_USE_SERIAL_USB FALSE
+#define HAL_USE_SERIAL_USB TRUE
#endif
/**
@@ -184,7 +184,7 @@
* @brief Enables the USB subsystem.
*/
#if !defined(HAL_USE_USB) || defined(__DOXYGEN__)
-#define HAL_USE_USB FALSE
+#define HAL_USE_USB TRUE
#endif
/**
@@ -412,7 +412,7 @@
* buffers.
*/
#if !defined(SERIAL_BUFFERS_SIZE) || defined(__DOXYGEN__)
-#define SERIAL_BUFFERS_SIZE 16
+#define SERIAL_BUFFERS_SIZE 1
#endif
/*===========================================================================*/
@@ -447,7 +447,7 @@
* buffers.
*/
#if !defined(SERIAL_USB_BUFFERS_SIZE) || defined(__DOXYGEN__)
-#define SERIAL_USB_BUFFERS_SIZE 256
+#define SERIAL_USB_BUFFERS_SIZE 512
#endif
/**
diff --git a/cfg/mcuconf.h b/cfg/mcuconf.h
index ffb098a57e645e0b0a359abaf55a1bdbcabcb9d1..2c3e198cb51f84d9aed3d68d86a91f4a6d8cfa76 100644
--- a/cfg/mcuconf.h
+++ b/cfg/mcuconf.h
@@ -39,23 +39,23 @@
* HAL driver system settings.
*/
#define STM32_NO_INIT FALSE
-#define STM32_HSI_ENABLED TRUE
-#define STM32_LSI_ENABLED TRUE
+#define STM32_HSI_ENABLED FALSE
+#define STM32_LSI_ENABLED FALSE
#define STM32_HSE_ENABLED TRUE
#define STM32_LSE_ENABLED FALSE
-#define STM32_CLOCK48_REQUIRED FALSE
+#define STM32_CLOCK48_REQUIRED TRUE
#define STM32_SW STM32_SW_PLL
#define STM32_PLLSRC STM32_PLLSRC_HSE
-#define STM32_PLLM_VALUE 8
-#define STM32_PLLN_VALUE 200
-#define STM32_PLLP_VALUE 2
-#define STM32_PLLQ_VALUE 7
+#define STM32_PLLM_VALUE 4
+#define STM32_PLLN_VALUE 192
+#define STM32_PLLP_VALUE 4
+#define STM32_PLLQ_VALUE 8
#define STM32_HPRE STM32_HPRE_DIV1
#define STM32_PPRE1 STM32_PPRE1_DIV4
#define STM32_PPRE2 STM32_PPRE2_DIV2
#define STM32_RTCSEL STM32_RTCSEL_LSI
#define STM32_RTCPRE_VALUE 8
-#define STM32_MCO1SEL STM32_MCO1SEL_HSI
+#define STM32_MCO1SEL STM32_MCO1SEL_PLL
#define STM32_MCO1PRE STM32_MCO1PRE_DIV1
#define STM32_MCO2SEL STM32_MCO2SEL_SYSCLK
#define STM32_MCO2PRE STM32_MCO2PRE_DIV5
@@ -261,7 +261,7 @@
* SERIAL driver system settings.
*/
#define STM32_SERIAL_USE_USART1 FALSE
-#define STM32_SERIAL_USE_USART2 TRUE
+#define STM32_SERIAL_USE_USART2 FALSE
#define STM32_SERIAL_USE_USART3 FALSE
#define STM32_SERIAL_USE_UART4 FALSE
#define STM32_SERIAL_USE_UART5 FALSE
@@ -325,7 +325,7 @@
/*
* USB driver system settings.
*/
-#define STM32_USB_USE_OTG1 FALSE
+#define STM32_USB_USE_OTG1 TRUE
#define STM32_USB_USE_OTG2 FALSE
#define STM32_USB_OTG1_IRQ_PRIORITY 14
#define STM32_USB_OTG2_IRQ_PRIORITY 14
diff --git a/src/serial.c b/src/serial.c
new file mode 100644
index 0000000000000000000000000000000000000000..a688a7c4e0cdef13e00defb3dd960075f98310af
--- /dev/null
+++ b/src/serial.c
@@ -0,0 +1,118 @@
+// This file is part of the execution-time evaluation for the qronos observer abstractions.
+// Copyright (C) 2022-2023 Tim Rheinfels <tim.rheinfels@fau.de>
+// See https://gitlab.cs.fau.de/qronos-state-abstractions/execution-time
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+///
+/// @file serial.c
+///
+/// @brief Provides the implementation of the serial over USB utilities
+///
+/// @author Tim Rheinfels (tim.rheinfels@fau.de)
+///
+
+#include "serial.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <ch.h>
+#include <hal.h>
+#include <chprintf.h>
+
+#include <crc32.h>
+#include <usb.h>
+
+///
+/// @brief Buffer used for formatting output
+///
+static char serial_buffer[1024u];
+
+void serial_init(void)
+{
+
+}
+
+void serial_printf(const char *fmt, ...)
+{
+
+ va_list ap;
+ va_start(ap, fmt);
+ size_t n = chvsnprintf(serial_buffer, sizeof(serial_buffer), fmt, ap);
+ va_end(ap);
+
+ // Check for overruns
+ osalDbgAssert(n < sizeof(serial_buffer), "line buffer overrun");
+
+ // Add to checksum and print
+ for(size_t i = 0u; i < n; ++i)
+ {
+ crc32_add(serial_buffer[i]);
+ }
+
+ // Write to serial driver
+ size_t written = streamWrite((BaseSequentialStream *) &usb_serial_driver, (const uint8_t *) serial_buffer, n);
+ osalDbgAssert(n == written, "lost characters");
+
+}
+
+void serial_print_vector(const char *name, float *M, size_t n)
+{
+ serial_printf("\"%s\": [", name);
+ for(size_t i = 0u; i < n; ++i)
+ {
+ serial_printf("%u,\n", serial_encode(M[i]));
+ }
+ serial_printf("],\n");
+}
+
+void serial_print_matrix(const char *name, float *M, size_t n, size_t m)
+{
+ serial_printf("\"%s\": [", name);
+ for(size_t i = 0u; i < n; ++i)
+ {
+ serial_printf("[");
+ for(size_t j = 0u; j < m; ++j)
+ {
+ serial_printf("%u,\n", serial_encode(M[i*m+j]));
+ }
+ serial_printf("],");
+ }
+ serial_printf("],\n");
+}
+
+void serial_reset_checksum(void)
+{
+
+ crc32_reset();
+
+}
+
+void serial_print_checksum(void)
+{
+
+ uint32_t checksum = crc32_get();
+
+ chprintf((BaseSequentialStream *) &usb_serial_driver, "CRC32: 0x%08x\n", checksum);
+
+}
+
+uint32_t serial_encode(float f)
+{
+ uint32_t i;
+ memcpy(&i, &f, sizeof(i));
+ return i;
+}
diff --git a/src/serial.h b/src/serial.h
new file mode 100644
index 0000000000000000000000000000000000000000..55cd2e09adbd7f25bb61a2af244e485e8fab75fd
--- /dev/null
+++ b/src/serial.h
@@ -0,0 +1,83 @@
+// This file is part of the execution-time evaluation for the qronos observer abstractions.
+// Copyright (C) 2022-2023 Tim Rheinfels <tim.rheinfels@fau.de>
+// See https://gitlab.cs.fau.de/qronos-state-abstractions/execution-time
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+///
+/// @file serial.h
+///
+/// @brief Provides the interface for the serial utilities
+///
+/// @author Tim Rheinfels (tim.rheinfels@fau.de)
+///
+
+#ifndef SERIAL_H
+#define SERIAL_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+///
+/// @brief Initializes the serial over USB utilities
+///
+void serial_init(void);
+
+///
+/// @brief Formats the string @p fmt using the variadic parameters and outputs the result via serial over USB
+///
+/// @param[in] fmt Format string
+/// @param[in] ... Parameters used for the format string @p fmt
+///
+void serial_printf(const char *fmt, ...);
+
+///
+/// @brief Formats the vector @p M of size @p n named @p name and outputs the result via serial over USB
+///
+/// @param[in] name Name for the vector
+/// @param[in] M Vector data
+/// @param[in] n Number of rows
+///
+void serial_print_vector(const char *name, float *M, size_t n);
+
+///
+/// @brief Formats the matrix @p M of size @p n by @p m named @p name and outputs the result via serial over USB
+///
+/// @param[in] name Name for the vector
+/// @param[in] M Vector data
+/// @param[in] n Number of rows
+/// @param[in] m Number of columns
+///
+void serial_print_matrix(const char *name, float *M, size_t n, size_t m);
+
+///
+/// @brief Resets the serial checksum
+///
+void serial_reset_checksum(void);
+
+///
+/// @brief Prints the accumulated serial checksum via serial over USB
+///
+void serial_print_checksum(void);
+
+///
+/// @brief Encodes the single-precision float @p f as interger
+///
+/// @param[in] f Single-precision float to encode
+///
+/// @returns 32-bit unsigned representing the float @p f
+///
+uint32_t serial_encode(float f);
+
+#endif // SERIAL_H
diff --git a/src/usb.c b/src/usb.c
new file mode 100644
index 0000000000000000000000000000000000000000..27232e5152f18d0ecc49316d0dbdf78934d13ee3
--- /dev/null
+++ b/src/usb.c
@@ -0,0 +1,423 @@
+// This file is part of the execution-time evaluation for the qronos observer abstractions.
+// Copyright (C) 2022-2023 Tim Rheinfels <tim.rheinfels@fau.de>
+// See https://gitlab.cs.fau.de/qronos-state-abstractions/execution-time
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+///
+/// @file usb.c
+///
+/// @brief Provides the implementation of the USB driver
+///
+/// @author Tim Rheinfels <tim.rheinfels@fau.de>
+///
+
+#include "usb.h"
+
+#include <ch.h>
+#include <hal.h>
+
+SerialUSBDriver usb_serial_driver;
+
+///
+/// @brief Flag indicating that a client terminal is connected
+///
+static volatile bool active = false;
+
+// Set USB active flag when SET_CONTROL_LINE_STATE request occurs
+///
+/// @brief USB request handler setting the @ref active flag when a SET_CONTROL_LINE_STATE request occurs or passes the request to @ref sduRequestsHook otherwise
+///
+/// @param[in] usb USB driver instance
+///
+/// @returns Either
+/// - true if the USB request was handled or
+/// - false otherwise
+///
+static bool usb_request_handler(USBDriver *usb)
+{
+ osalSysLockFromISR();
+ uint8_t rtype = usb->setup[0u];
+ if(((rtype & USB_RTYPE_DIR_MASK) == USB_RTYPE_DIR_HOST2DEV)
+ && (((rtype & USB_RTYPE_TYPE_MASK) == USB_RTYPE_TYPE_CLASS))
+ && (((rtype & USB_RTYPE_RECIPIENT_MASK) == USB_RTYPE_RECIPIENT_INTERFACE)))
+ {
+ if((usb->setup[1u] == 0x22u))
+ {
+ active = true;
+ osalSysUnlockFromISR();
+ return true;
+ }
+ }
+
+ osalSysUnlockFromISR();
+ return sduRequestsHook(usb);
+}
+
+// Adapted from chibios-contrib/demo/STM32/RT-STM32F411-DISCOVERY-blinker
+
+// Forward declarations
+
+///
+/// @brief USB config structure for ChibiOS/HAL driver
+///
+extern const USBConfig usbcfg;
+
+///
+/// @brief Serial over USB config structure for ChibiOS/HAL driver
+///
+extern const SerialUSBConfig serusbcfg;
+
+#define USBD1_DATA_REQUEST_EP 1 ///< Endpoint for data requests (IN direction)
+#define USBD1_DATA_AVAILABLE_EP 1 ///< Endpoint for data available (OUT direction)
+#define USBD1_INTERRUPT_REQUEST_EP 2 ///< Endpoint for interrupt requests (IN direction)
+
+///
+/// @brief USB device descriptor
+///
+static const uint8_t vcom_device_descriptor_data[18] = {
+ USB_DESC_DEVICE (0x0110, /* bcdUSB (1.1). */
+ 0x02, /* bDeviceClass (CDC). */
+ 0x00, /* bDeviceSubClass. */
+ 0x00, /* bDeviceProtocol. */
+ 0x40, /* bMaxPacketSize. */
+ 0xCAFE, /* idVendor. */
+ 0xF00D, /* idProduct. */
+ 0x0200, /* bcdDevice. */
+ 1, /* iManufacturer. */
+ 2, /* iProduct. */
+ 3, /* iSerialNumber. */
+ 1) /* bNumConfigurations. */
+};
+
+///
+/// @brief Wrapper for USB device descriptor
+///
+static const USBDescriptor vcom_device_descriptor = {
+ sizeof vcom_device_descriptor_data,
+ vcom_device_descriptor_data
+};
+
+///
+/// @brief USB configuration descriptor
+///
+static const uint8_t vcom_configuration_descriptor_data[67] = {
+ /* Configuration Descriptor.*/
+ USB_DESC_CONFIGURATION(67, /* wTotalLength. */
+ 0x02, /* bNumInterfaces. */
+ 0x01, /* bConfigurationValue. */
+ 0, /* iConfiguration. */
+ 0xC0, /* bmAttributes (self powered). */
+ 50), /* bMaxPower (100mA). */
+ /* Interface Descriptor.*/
+ USB_DESC_INTERFACE (0x00, /* bInterfaceNumber. */
+ 0x00, /* bAlternateSetting. */
+ 0x01, /* bNumEndpoints. */
+ 0x02, /* bInterfaceClass (Communications
+ Interface Class, CDC section
+ 4.2). */
+ 0x02, /* bInterfaceSubClass (Abstract
+ Control Model, CDC section 4.3). */
+ 0x01, /* bInterfaceProtocol (AT commands,
+ CDC section 4.4). */
+ 0), /* iInterface. */
+ /* Header Functional Descriptor (CDC section 5.2.3).*/
+ USB_DESC_BYTE (5), /* bLength. */
+ USB_DESC_BYTE (0x24), /* bDescriptorType (CS_INTERFACE). */
+ USB_DESC_BYTE (0x00), /* bDescriptorSubtype (Header
+ Functional Descriptor. */
+ USB_DESC_BCD (0x0110), /* bcdCDC. */
+ /* Call Management Functional Descriptor. */
+ USB_DESC_BYTE (5), /* bFunctionLength. */
+ USB_DESC_BYTE (0x24), /* bDescriptorType (CS_INTERFACE). */
+ USB_DESC_BYTE (0x01), /* bDescriptorSubtype (Call Management
+ Functional Descriptor). */
+ USB_DESC_BYTE (0x00), /* bmCapabilities (D0+D1). */
+ USB_DESC_BYTE (0x01), /* bDataInterface. */
+ /* ACM Functional Descriptor.*/
+ USB_DESC_BYTE (4), /* bFunctionLength. */
+ USB_DESC_BYTE (0x24), /* bDescriptorType (CS_INTERFACE). */
+ USB_DESC_BYTE (0x02), /* bDescriptorSubtype (Abstract
+ Control Management Descriptor). */
+ USB_DESC_BYTE (0x02), /* bmCapabilities. */
+ /* Union Functional Descriptor.*/
+ USB_DESC_BYTE (5), /* bFunctionLength. */
+ USB_DESC_BYTE (0x24), /* bDescriptorType (CS_INTERFACE). */
+ USB_DESC_BYTE (0x06), /* bDescriptorSubtype (Union
+ Functional Descriptor). */
+ USB_DESC_BYTE (0x00), /* bMasterInterface (Communication
+ Class Interface). */
+ USB_DESC_BYTE (0x01), /* bSlaveInterface0 (Data Class
+ Interface). */
+ /* Endpoint 2 Descriptor.*/
+ USB_DESC_ENDPOINT (USBD1_INTERRUPT_REQUEST_EP|0x80,
+ 0x03, /* bmAttributes (Interrupt). */
+ 0x0008, /* wMaxPacketSize. */
+ 0xFF), /* bInterval. */
+ /* Interface Descriptor.*/
+ USB_DESC_INTERFACE (0x01, /* bInterfaceNumber. */
+ 0x00, /* bAlternateSetting. */
+ 0x02, /* bNumEndpoints. */
+ 0x0A, /* bInterfaceClass (Data Class
+ Interface, CDC section 4.5). */
+ 0x00, /* bInterfaceSubClass (CDC section
+ 4.6). */
+ 0x00, /* bInterfaceProtocol (CDC section
+ 4.7). */
+ 0x00), /* iInterface. */
+ /* Endpoint 3 Descriptor.*/
+ USB_DESC_ENDPOINT (USBD1_DATA_AVAILABLE_EP, /* bEndpointAddress.*/
+ 0x02, /* bmAttributes (Bulk). */
+ 0x0040, /* wMaxPacketSize. */
+ 0x00), /* bInterval. */
+ /* Endpoint 1 Descriptor.*/
+ USB_DESC_ENDPOINT (USBD1_DATA_REQUEST_EP|0x80, /* bEndpointAddress.*/
+ 0x02, /* bmAttributes (Bulk). */
+ 0x0040, /* wMaxPacketSize. */
+ 0x00) /* bInterval. */
+};
+
+///
+/// @brief Wrapper for USB configuration descriptor
+///
+static const USBDescriptor vcom_configuration_descriptor = {
+ sizeof vcom_configuration_descriptor_data,
+ vcom_configuration_descriptor_data
+};
+
+///
+/// @brief Language descriptor representing U.S. English
+///
+static const uint8_t vcom_string0[] = {
+ USB_DESC_BYTE(4), /* bLength. */
+ USB_DESC_BYTE(USB_DESCRIPTOR_STRING), /* bDescriptorType. */
+ USB_DESC_WORD(0x0409) /* wLANGID (U.S. English). */
+};
+
+///
+/// @brief String descriptor for vendor clear name
+///
+static const uint8_t vcom_string1[] = {
+ USB_DESC_BYTE(38), /* bLength. */
+ USB_DESC_BYTE(USB_DESCRIPTOR_STRING), /* bDescriptorType. */
+ 'i', 0, 'n', 0, 'f', 0, '4', 0, '@', 0, 'F', 0, 'A', 0, 'U', 0,
+};
+
+///
+/// @brief String descriptor for device clear name
+///
+static const uint8_t vcom_string2[] = {
+ USB_DESC_BYTE(88), /* bLength. */
+ USB_DESC_BYTE(USB_DESCRIPTOR_STRING), /* bDescriptorType. */
+ 'S', 0, 't', 0, 'a', 0, 't', 0, 'e', 0, ' ', 0,
+ 'A', 0, 'b', 0, 's', 0, 't', 0, 'r', 0, 'a', 0, 'c', 0, 't', 0, 'i', 0, 'o', 0, 'n', 0, 's', 0, ' ', 0,
+ 'E', 0, 'x', 0, 'e', 0, 'c', 0, 'u', 0, 't', 0, 'i', 0, 'o', 0, 'n', 0, ' ', 0,
+ 'T', 0, 'i', 0, 'm', 0, 'e', 0, ' ', 0,
+ 'B', 0, 'e', 0, 'n', 0, 'c', 0, 'h', 0, 'm', 0, 'a', 0, 'r', 0, 'k', 0,
+};
+
+///
+/// @brief Wrapper for USB string descriptors
+///
+static const USBDescriptor vcom_strings[] = {
+ {sizeof(vcom_string0), vcom_string0},
+ {sizeof(vcom_string1), vcom_string1},
+ {sizeof(vcom_string2), vcom_string2}
+};
+
+///
+/// @brief Handles descriptor requests
+///
+/// @param[in] usbp USB driver instance
+/// @param[in] dtype Descriptor type
+/// @param[in] dindex Descriptor index
+/// @param[in] lang Language identifier
+///
+/// @returns Either
+/// - pointer to the requested descriptor of parameters are valid or
+/// - NULL otherwise
+///
+static const USBDescriptor *get_descriptor(USBDriver *usbp,
+ uint8_t dtype,
+ uint8_t dindex,
+ uint16_t lang) {
+
+ (void)usbp;
+ (void)lang;
+ switch (dtype) {
+ case USB_DESCRIPTOR_DEVICE:
+ return &vcom_device_descriptor;
+ case USB_DESCRIPTOR_CONFIGURATION:
+ return &vcom_configuration_descriptor;
+ case USB_DESCRIPTOR_STRING:
+ if (dindex < 3)
+ return &vcom_strings[dindex];
+ }
+ return NULL;
+}
+
+///
+/// @brief State for the IN direction of endpoint 1
+///
+static USBInEndpointState ep1instate;
+
+///
+/// @brief State for the OUT direction of endpoint 1
+///
+static USBOutEndpointState ep1outstate;
+
+///
+/// @brief Configuration for endpoint 1
+///
+static const USBEndpointConfig ep1config = {
+ USB_EP_MODE_TYPE_BULK,
+ NULL,
+ sduDataTransmitted,
+ sduDataReceived,
+ 0x0040,
+ 0x0040,
+ &ep1instate,
+ &ep1outstate,
+ 2,
+ NULL
+};
+
+///
+/// @brief State for the IN direction of endpoint 2
+///
+static USBInEndpointState ep2instate;
+
+///
+/// @brief Configuration for endpoint 2
+///
+static const USBEndpointConfig ep2config = {
+ USB_EP_MODE_TYPE_INTR,
+ NULL,
+ sduInterruptTransmitted,
+ NULL,
+ 0x0010,
+ 0x0000,
+ &ep2instate,
+ NULL,
+ 1,
+ NULL
+};
+
+///
+/// @brief USB event handler for the active flag and SDU driver state
+///
+/// @param[in] usbp USB driver instance
+/// @param[in] event Event to handle
+///
+static void usb_event(USBDriver *usbp, usbevent_t event) {
+
+ switch (event) {
+ case USB_EVENT_ADDRESS:
+ return;
+ case USB_EVENT_CONFIGURED:
+ chSysLockFromISR();
+
+ /* Enables the endpoints specified into the configuration.
+ Note, this callback is invoked from an ISR so I-Class functions
+ must be used.*/
+ active = false;
+ usbInitEndpointI(usbp, USBD1_DATA_REQUEST_EP, &ep1config);
+ usbInitEndpointI(usbp, USBD1_INTERRUPT_REQUEST_EP, &ep2config);
+
+ /* Resetting the state of the CDC subsystem.*/
+ sduConfigureHookI(&usb_serial_driver);
+
+ chSysUnlockFromISR();
+ return;
+ case USB_EVENT_RESET:
+ /* Falls into.*/
+ case USB_EVENT_UNCONFIGURED:
+ /* Falls into.*/
+ case USB_EVENT_SUSPEND:
+ chSysLockFromISR();
+
+ /* Disconnection event on suspend.*/
+ active = false;
+ sduSuspendHookI(&usb_serial_driver);
+
+ chSysUnlockFromISR();
+ return;
+ case USB_EVENT_WAKEUP:
+ chSysLockFromISR();
+
+ /* Connection event on wakeup.*/
+ sduWakeupHookI(&usb_serial_driver);
+
+ chSysUnlockFromISR();
+ return;
+ case USB_EVENT_STALLED:
+ return;
+ }
+ return;
+}
+
+///
+/// @brief Handler for start-of-frame condition calling the SDU sof handler
+///
+/// @param[in] usbp USB driver instance
+///
+static void sof_handler(USBDriver *usbp) {
+
+ (void)usbp;
+
+ osalSysLockFromISR();
+ sduSOFHookI(&usb_serial_driver);
+ osalSysUnlockFromISR();
+}
+
+///
+/// @brief USB driver configuration
+///
+const USBConfig usbcfg = {
+ usb_event,
+ get_descriptor,
+ usb_request_handler,
+ sof_handler
+};
+
+///
+/// @brief Serial over USB driver configuration
+///
+const SerialUSBConfig serusbcfg = {
+ &USBD1,
+ USBD1_DATA_REQUEST_EP,
+ USBD1_DATA_AVAILABLE_EP,
+ USBD1_INTERRUPT_REQUEST_EP
+};
+
+void usb_init(void)
+{
+
+ palSetPadMode(GPIOA, 11, PAL_MODE_ALTERNATE(10));
+ palSetPadMode(GPIOA, 12, PAL_MODE_ALTERNATE(10));
+
+ sduObjectInit(&usb_serial_driver);
+ sduStart(&usb_serial_driver, &serusbcfg);
+
+ usbDisconnectBus(&USBD1);
+ chThdSleepMilliseconds(1000);
+ usbStart(&USBD1, &usbcfg);
+ usbConnectBus(&USBD1);
+
+}
+
+bool usb_active(void)
+{
+ return active;
+}
diff --git a/src/usb.h b/src/usb.h
new file mode 100644
index 0000000000000000000000000000000000000000..85a47eddd1cbfb1ca9d1b363a523c6292afdc970
--- /dev/null
+++ b/src/usb.h
@@ -0,0 +1,51 @@
+// This file is part of the execution-time evaluation for the qronos observer abstractions.
+// Copyright (C) 2022-2023 Tim Rheinfels <tim.rheinfels@fau.de>
+// See https://gitlab.cs.fau.de/qronos-state-abstractions/execution-time
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+///
+/// @file usb.h
+///
+/// @brief Provides the interface for the USB driver
+///
+/// @author Tim Rheinfels <tim.rheinfels@fau.de>
+///
+
+#ifndef USB_H
+#define USB_H
+
+#include <ch.h>
+#include <hal.h>
+
+///
+/// @brief USB serial driver instance
+///
+extern SerialUSBDriver usb_serial_driver;
+
+///
+/// @brief Initializes the USB stack
+///
+void usb_init(void);
+
+///
+/// @brief Checks if there is a terminal attached to the USB over serial driver
+///
+/// @returns Either
+/// - true if a client terminal is attached or
+/// - false otherwise
+///
+bool usb_active(void);
+
+#endif // USB_H