added USB CDC based shell

git-svn-id: https://svn.spreadspace.org/mur.sat@835 7de4ea59-55d0-425e-a1af-a3118ea81d4c

9 files changed, 565 insertions, 15 deletions

diff --git a/software/mpu/Makefile b/software/mpu/Makefile
index 8dcb9ed..55f9a24 100644
--- a/software/mpu/Makefile
+++ b/software/mpu/Makefile
@@ -10,7 +10,7 @@ endif
 
 # C specific options here (added to USE_OPT).
 ifeq ($(USE_COPT),)
-  USE_COPT = 
+  USE_COPT =
 endif
 
 # C++ specific options here (added to USE_OPT).
@@ -77,9 +77,10 @@ CSRC = $(PORTSRC) \
        $(HALSRC) \
        $(PLATFORMSRC) \
        $(BOARDSRC) \
-       $(CHIBIOS)/os/various/evtimer.c \
-       $(CHIBIOS)/os/various/syscalls.c \
+       $(CHIBIOS)/os/various/shell.c \
+       $(CHIBIOS)/os/various/chprintf.c \
        heartbeat.c \
+       usb-cdc-shell.c \
        main.c
 
 # C++ sources that can be compiled in ARM or THUMB mode depending on the global
diff --git a/software/mpu/board/board.c b/software/mpu/board/board.c
index c1a077e..2560a73 100644
--- a/software/mpu/board/board.c
+++ b/software/mpu/board/board.c
@@ -49,4 +49,8 @@ void __early_init(void) {
  * Board-specific initialization code.
  */
 void boardInit(void) {
+  /*
+   * Disable JTAG-DP and SW-DP.
+   */
+  AFIO->MAPR = AFIO_MAPR_SWJ_CFG_DISABLE;
 }
diff --git a/software/mpu/board/board.h b/software/mpu/board/board.h
index 018a45e..3004909 100644
--- a/software/mpu/board/board.h
+++ b/software/mpu/board/board.h
@@ -73,14 +73,12 @@
 /*
  * Port A setup.
  * Everything input with pull-up except:
- * PA2  - Alternate output  (USART2 TX).
- * PA3  - Normal input      (USART2 RX).
  * PA8  - Push Pull output (LED).
  * PA11 - Normal input      (USB DM).
  * PA12 - Normal input      (USB DP).
  * PA13 - Push Pull output (USB DISC).
  */
-#define VAL_GPIOACRL            0x88884B88      /*  PA7...PA0 */
+#define VAL_GPIOACRL            0x88888888      /*  PA7...PA0 */
 #define VAL_GPIOACRH            0x88344883      /* PA15...PA8 */
 #define VAL_GPIOAODR            0xFFFFFFFF
 
diff --git a/software/mpu/halconf.h b/software/mpu/halconf.h
index f41266a..72b4e93 100644
--- a/software/mpu/halconf.h
+++ b/software/mpu/halconf.h
@@ -125,7 +125,7 @@
  * @brief   Enables the SERIAL subsystem.
  */
 #if !defined(HAL_USE_SERIAL) || defined(__DOXYGEN__)
-#define HAL_USE_SERIAL              TRUE
+#define HAL_USE_SERIAL              FALSE
 #endif
 
 /**
diff --git a/software/mpu/main.c b/software/mpu/main.c
index 8f411d5..bf85609 100644
--- a/software/mpu/main.c
+++ b/software/mpu/main.c
@@ -34,6 +34,7 @@
 #include "hal.h"
 
 #include "heartbeat.h"
+#include "usb-cdc-shell.h"
 
 /*
  * Application entry point.
@@ -50,14 +51,9 @@ int main(void) {
   halInit();
   chSysInit();
 
-
   heartbeatInit();
-
-  /*
-   * Normal main() thread activity, in this demo it does nothing except
-   * sleeping in a loop.
-   */
+  usbCDCShellInit();
   while (TRUE) {
-    chThdSleepMilliseconds(10000);
+    usbCDCShellRun();
   }
 }
diff --git a/software/mpu/mcuconf.h b/software/mpu/mcuconf.h
index 6a03346..af13f57 100644
--- a/software/mpu/mcuconf.h
+++ b/software/mpu/mcuconf.h
@@ -151,7 +151,7 @@
  * 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
diff --git a/software/mpu/usb-cdc-descriptor.h b/software/mpu/usb-cdc-descriptor.h
new file mode 100644
index 0000000..41fc5a9
--- /dev/null
+++ b/software/mpu/usb-cdc-descriptor.h
@@ -0,0 +1,204 @@
+/*
+ *
+ *  mur.sat
+ *
+ *  Somewhen in the year 2012, mur.at will have a nano satellite launched
+ *  into a low earth orbit (310 km above the surface of our planet). The
+ *  satellite itself is a TubeSat personal satellite kit, developed and
+ *  launched by interorbital systems. mur.sat is a joint venture of mur.at,
+ *  ESC im Labor and realraum.
+ *
+ *  Please visit the project hompage at sat.mur.at for further information.
+ *
+ *
+ *  Copyright (C) 2013 Christian Pointner <equinox@mur.at>
+ *
+ *  This file is part of mur.sat.
+ *
+ *  mur.sat 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
+ *  any later version.
+ *
+ *  mur.sat 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 mur.sat. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef MURSAT_usb_cdc_descriptor_h_INCLUDED
+#define MURSAT_usb_cdc_descriptor_h_INCLUDED
+
+/*
+ * Endpoints to be used for USBD1.
+ */
+#define USBD1_DATA_REQUEST_EP           1
+#define USBD1_DATA_AVAILABLE_EP         1
+#define USBD1_INTERRUPT_REQUEST_EP      2
+
+/*
+ * 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.                  */
+                         0x0483,        /* idVendor (ST).                   */
+                         0x5740,        /* idProduct.                       */
+                         0x0200,        /* bcdDevice.                       */
+                         1,             /* iManufacturer.                   */
+                         2,             /* iProduct.                        */
+                         3,             /* iSerialNumber.                   */
+                         1)             /* bNumConfigurations.              */
+};
+
+/*
+ * Device Descriptor wrapper.
+ */
+static const USBDescriptor vcom_device_descriptor = {
+  sizeof vcom_device_descriptor_data,
+  vcom_device_descriptor_data
+};
+
+/* Configuration Descriptor tree for a CDC.*/
+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.                       */
+};
+
+/*
+ * Configuration Descriptor wrapper.
+ */
+static const USBDescriptor vcom_configuration_descriptor = {
+  sizeof vcom_configuration_descriptor_data,
+  vcom_configuration_descriptor_data
+};
+
+/*
+ * U.S. English language identifier.
+ */
+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).          */
+};
+
+/*
+ * Vendor string.
+ */
+static const uint8_t vcom_string1[] = {
+  USB_DESC_BYTE(14),                    /* bLength.                         */
+  USB_DESC_BYTE(USB_DESCRIPTOR_STRING), /* bDescriptorType.                 */
+  'm', 0, 'u', 0, 'r', 0, '.', 0, 'a', 0, 't', 0
+};
+
+/*
+ * Device Description string.
+ */
+static const uint8_t vcom_string2[] = {
+  USB_DESC_BYTE(24),                    /* bLength.                         */
+  USB_DESC_BYTE(USB_DESCRIPTOR_STRING), /* bDescriptorType.                 */
+  'm', 0, 'u', 0, 'r', 0, '.', 0, 's', 0, 'a', 0, 't', 0, ' ', 0,
+  'M', 0, 'P', 0, 'U', 0
+};
+
+/*
+ * Serial Number string.
+ */
+static const uint8_t vcom_string3[] = {
+  USB_DESC_BYTE(8),                     /* bLength.                         */
+  USB_DESC_BYTE(USB_DESCRIPTOR_STRING), /* bDescriptorType.                 */
+  '0', 0,
+  '1', 0,
+  '0', 0
+};
+
+/*
+ * Strings wrappers array.
+ */
+static const USBDescriptor vcom_strings[] = {
+  {sizeof vcom_string0, vcom_string0},
+  {sizeof vcom_string1, vcom_string1},
+  {sizeof vcom_string2, vcom_string2},
+  {sizeof vcom_string3, vcom_string3}
+};
+
+
+#endif
diff --git a/software/mpu/usb-cdc-shell.c b/software/mpu/usb-cdc-shell.c
new file mode 100644
index 0000000..b863b58
--- /dev/null
+++ b/software/mpu/usb-cdc-shell.c
@@ -0,0 +1,308 @@
+/*
+ *
+ *  mur.sat
+ *
+ *  Somewhen in the year 2012, mur.at will have a nano satellite launched
+ *  into a low earth orbit (310 km above the surface of our planet). The
+ *  satellite itself is a TubeSat personal satellite kit, developed and
+ *  launched by interorbital systems. mur.sat is a joint venture of mur.at,
+ *  ESC im Labor and realraum.
+ *
+ *  Please visit the project hompage at sat.mur.at for further information.
+ *
+ *
+ *  Copyright (C) 2013 Christian Pointner <equinox@mur.at>
+ *
+ *  This file is part of mur.sat.
+ *
+ *  mur.sat 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
+ *  any later version.
+ *
+ *  mur.sat 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 mur.sat. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+// this heavily leans on the USB-CDC testhal Demo from chibiOS
+/*
+    ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
+
+
+#include <stdio.h>
+#include <string.h>
+
+#include "ch.h"
+#include "hal.h"
+#include "test.h"
+
+#include "shell.h"
+#include "chprintf.h"
+
+#include "usb-cdc-shell.h"
+#include "usb-cdc-descriptor.h"
+
+
+static SerialUSBDriver SDU1;
+
+/*
+ * Handles the GET_DESCRIPTOR callback. All required descriptors must be
+ * handled here.
+ */
+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 < 4)
+      return &vcom_strings[dindex];
+  }
+  return NULL;
+}
+
+static USBInEndpointState ep1instate;
+static USBOutEndpointState ep1outstate;
+static const USBEndpointConfig ep1config = {
+  USB_EP_MODE_TYPE_BULK,
+  NULL,
+  sduDataTransmitted,
+  sduDataReceived,
+  0x0040,
+  0x0040,
+  &ep1instate,
+  &ep1outstate,
+  1,
+  NULL
+};
+
+static USBInEndpointState ep2instate;
+static const USBEndpointConfig ep2config = {
+  USB_EP_MODE_TYPE_INTR,
+  NULL,
+  sduInterruptTransmitted,
+  NULL,
+  0x0010,
+  0x0000,
+  &ep2instate,
+  NULL,
+  1,
+  NULL
+};
+
+/*
+ * Handles the USB driver global events.
+ */
+static void usb_event(USBDriver *usbp, usbevent_t event) {
+
+  switch (event) {
+  case USB_EVENT_RESET:
+    return;
+  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.*/
+    usbInitEndpointI(usbp, USBD1_DATA_REQUEST_EP, &ep1config);
+    usbInitEndpointI(usbp, USBD1_INTERRUPT_REQUEST_EP, &ep2config);
+
+    /* Resetting the state of the CDC subsystem.*/
+    sduConfigureHookI(&SDU1);
+
+    chSysUnlockFromIsr();
+    return;
+  case USB_EVENT_SUSPEND:
+    return;
+  case USB_EVENT_WAKEUP:
+    return;
+  case USB_EVENT_STALLED:
+    return;
+  }
+  return;
+}
+
+/*
+ * USB driver configuration.
+ */
+static const USBConfig usbcfg = {
+  usb_event,
+  get_descriptor,
+  sduRequestsHook,
+  NULL
+};
+
+/*
+ * Serial over USB driver configuration.
+ */
+static const SerialUSBConfig serusbcfg = {
+  &USBD1,
+  USBD1_DATA_REQUEST_EP,
+  USBD1_DATA_AVAILABLE_EP,
+  USBD1_INTERRUPT_REQUEST_EP
+};
+
+/*===========================================================================*/
+/* Command line related.                                                     */
+/*===========================================================================*/
+
+#define SHELL_WA_SIZE   THD_WA_SIZE(2048)
+#define TEST_WA_SIZE    THD_WA_SIZE(256)
+
+static void cmd_mem(BaseSequentialStream *chp, int argc, char *argv[]) {
+  size_t n, size;
+
+  (void)argv;
+  if (argc > 0) {
+    chprintf(chp, "Usage: mem\r\n");
+    return;
+  }
+  n = chHeapStatus(NULL, &size);
+  chprintf(chp, "core free memory : %u bytes\r\n", chCoreStatus());
+  chprintf(chp, "heap fragments   : %u\r\n", n);
+  chprintf(chp, "heap free total  : %u bytes\r\n", size);
+}
+
+static void cmd_threads(BaseSequentialStream *chp, int argc, char *argv[]) {
+  static const char *states[] = {THD_STATE_NAMES};
+  Thread *tp;
+
+  (void)argv;
+  if (argc > 0) {
+    chprintf(chp, "Usage: threads\r\n");
+    return;
+  }
+  chprintf(chp, "    addr    stack prio refs     state time\r\n");
+  tp = chRegFirstThread();
+  do {
+    chprintf(chp, "%.8lx %.8lx %4lu %4lu %9s %lu\r\n",
+            (uint32_t)tp, (uint32_t)tp->p_ctx.r13,
+            (uint32_t)tp->p_prio, (uint32_t)(tp->p_refs - 1),
+            states[tp->p_state], (uint32_t)tp->p_time);
+    tp = chRegNextThread(tp);
+  } while (tp != NULL);
+}
+
+static void cmd_test(BaseSequentialStream *chp, int argc, char *argv[]) {
+  Thread *tp;
+
+  (void)argv;
+  if (argc > 0) {
+    chprintf(chp, "Usage: test\r\n");
+    return;
+  }
+  tp = chThdCreateFromHeap(NULL, TEST_WA_SIZE, chThdGetPriority(),
+                           TestThread, chp);
+  if (tp == NULL) {
+    chprintf(chp, "out of memory\r\n");
+    return;
+  }
+  chThdWait(tp);
+}
+
+static void cmd_write(BaseSequentialStream *chp, int argc, char *argv[]) {
+  static uint8_t buf[] =
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
+      "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef";
+
+  (void)argv;
+  if (argc > 0) {
+    chprintf(chp, "Usage: write\r\n");
+    return;
+  }
+
+  while (chnGetTimeout((BaseChannel *)chp, TIME_IMMEDIATE) == Q_TIMEOUT) {
+    chSequentialStreamWrite(&SDU1, buf, sizeof buf - 1);
+  }
+  chprintf(chp, "\r\n\nstopped\r\n");
+}
+
+static const ShellCommand commands[] = {
+  {"mem", cmd_mem},
+  {"threads", cmd_threads},
+  {"test", cmd_test},
+  {"write", cmd_write},
+  {NULL, NULL}
+};
+
+static const ShellConfig shell_cfg1 = {
+  (BaseSequentialStream *)&SDU1,
+  commands
+};
+
+/*===========================================================================*/
+/* Public Interface.                                                         */
+/*===========================================================================*/
+
+void usbCDCShellInit(void)
+{
+  sduObjectInit(&SDU1);
+  sduStart(&SDU1, &serusbcfg);
+
+  palSetPad(USB_DISC__PORT, USB_DISC__PIN);
+  usbDisconnectBus(serusbcfg.usbp);
+  chThdSleepMilliseconds(1500);
+  usbStart(serusbcfg.usbp, &usbcfg);
+  usbConnectBus(serusbcfg.usbp);
+  palClearPad(USB_DISC__PORT, USB_DISC__PIN);
+
+  shellInit();
+}
+
+
+void usbCDCShellRun(void)
+{
+  Thread *shelltp = NULL;
+
+  while (TRUE) {
+    if (!shelltp && (SDU1.config->usbp->state == USB_ACTIVE))
+      shelltp = shellCreate(&shell_cfg1, SHELL_WA_SIZE, NORMALPRIO);
+    else if (chThdTerminated(shelltp)) {
+      chThdRelease(shelltp);    /* Recovers memory of the previous shell.   */
+      shelltp = NULL;           /* Triggers spawning of a new shell.        */
+    }
+    chThdSleepMilliseconds(1000);
+  }
+}
diff --git a/software/mpu/usb-cdc-shell.h b/software/mpu/usb-cdc-shell.h
new file mode 100644
index 0000000..f44df9d
--- /dev/null
+++ b/software/mpu/usb-cdc-shell.h
@@ -0,0 +1,39 @@
+/*
+ *
+ *  mur.sat
+ *
+ *  Somewhen in the year 2012, mur.at will have a nano satellite launched
+ *  into a low earth orbit (310 km above the surface of our planet). The
+ *  satellite itself is a TubeSat personal satellite kit, developed and
+ *  launched by interorbital systems. mur.sat is a joint venture of mur.at,
+ *  ESC im Labor and realraum.
+ *
+ *  Please visit the project hompage at sat.mur.at for further information.
+ *
+ *
+ *  Copyright (C) 2013 Christian Pointner <equinox@mur.at>
+ *
+ *  This file is part of mur.sat.
+ *
+ *  mur.sat 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
+ *  any later version.
+ *
+ *  mur.sat 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 mur.sat. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef MURSAT_usb_cdc_shell_h_INCLUDED
+#define MURSAT_usb_cdc_shell_h_INCLUDED
+
+void usbCDCShellInit(void);
+void usbCDCShellRun(void);
+
+#endif