Bootloaders/CDC/BootloaderCDC.txt

   1 /** \file
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   6
   7 /** \mainpage CDC Class USB AVR Bootloader
   8  *
   9  *  \section Sec_Compat Demo Compatibility:
  10  *
  11  *  The following list indicates what microcontrollers are compatible with this demo.
  12  *
  13  *  \li Series 7 USB AVRs (AT90USBxxx7)
  14  *  \li Series 6 USB AVRs (AT90USBxxx6)
  15  *  \li Series 4 USB AVRs (ATMEGAxxU4)
  16  *  \li Series 2 USB AVRs (AT90USBxx2, ATMEGAxxU2)
  17  *
  18  *  \section Sec_Info USB Information:
  19  *
  20  *  The following table gives a rundown of the USB utilization of this demo.
  21  *
  22  *  <table>
  23  *   <tr>
  24  *    <td><b>USB Mode:</b></td>
  25  *    <td>Device</td>
  26  *   </tr>
  27  *   <tr>
  28  *    <td><b>USB Class:</b></td>
  29  *    <td>Communications Device Class (CDC)</td>
  30  *   </tr>
  31  *   <tr>
  32  *    <td><b>USB Subclass:</b></td>
  33  *    <td>Abstract Control Model (ACM)</td>
  34  *   </tr>
  35  *   <tr>
  36  *    <td><b>Relevant Standards:</b></td>
  37  *    <td>USBIF CDC Class Standard</td>
  38  *   </tr>
  39  *   <tr>
  40  *    <td><b>Supported USB Speeds:</b></td>
  41  *    <td>Full Speed Mode</td>
  42  *   </tr>
  43  *  </table>
  44  *
  45  *  \section Sec_Description Project Description:
  46  *
  47  *  This bootloader enumerates to the host as a CDC Class device (virtual serial port), allowing for AVR109
  48  *  protocol compatible programming software to load firmware onto the AVR.
  49  *
  50  *  Out of the box this bootloader builds for the AT90USB1287 with an 8KB bootloader section size, and will fit
  51  *  into 4KB of bootloader space. If you wish to alter this size and/or change the AVR model, you will need to
  52  *  edit the MCU, FLASH_SIZE_KB and BOOT_SECTION_SIZE_KB values in the accompanying makefile.
  53  *
  54  *  When the bootloader is running, the board's LED(s) will flash at regular intervals to distinguish the
  55  *  bootloader from the normal user application.
  56  *
  57  *  \warning <b>THIS BOOTLOADER IS NOT SECURE.</b> Malicious entities can recover written data, even if the device
  58  *           lockbits are set.
  59  *
  60  *  \section Sec_Running Running the Bootloader
  61  *
  62  *  On the USB AVR8 devices, setting the \c HWBE device fuse will cause the bootloader to run if the \c HWB pin of
  63  *  the AVR is grounded when the device is reset.
  64  *
  65  *  The are two behaviours of this bootloader, depending on the device's fuses:
  66  *
  67  *  <b>If the device's BOOTRST fuse is set</b>, the bootloader will run any time the system is reset from
  68  *  the external reset pin, unless no valid user application has been loaded. To initiate the bootloader, the
  69  *  device's external reset pin should be grounded momentarily.
  70  *
  71  *  <b>If the device's BOOTRST fuse is not set</b>, the bootloader will run only if initiated via a software
  72  *  jump, or if the \c HWB pin was low during the last device reset (if the \c HWBE fuse is set).
  73  *
  74  *  For board specific exceptions to the above, see below.
  75  *
  76  *  \subsection SSec_XPLAIN Atmel Xplain Board
  77  *  Ground the USB AVR JTAG's \c TCK pin to ground when powering on the board to start the bootloader. This assumes the
  78  *  \c HWBE fuse is cleared and the \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board.
  79  *
  80  *  \subsection SSec_Leonardo Arduino Leonardo Board
  81  *  Ground \c IO13 when powering the board to start the bootloader. This assumes the \c HWBE fuse is cleared and the
  82  *  \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board.
  83  *
  84  *  \section Sec_Installation Driver Installation
  85  *
  86  *  After running this bootloader for the first time on a new computer, you will need to supply the .INF
  87  *  file located in this bootloader project's directory as the device's driver when running under Windows.
  88  *  This will enable Windows to use its inbuilt CDC drivers, negating the need for custom drivers for the
  89  *  device. Other Operating Systems should automatically use their own inbuilt CDC-ACM drivers.
  90  *
  91  *  \section Sec_HostApp Host Controller Application
  92  *
  93  *  This bootloader is compatible with the open source application AVRDUDE, Atmel's AVRPROG, or other
  94  *  applications implementing the AVR109 protocol, which is documented on the Atmel website as an application
  95  *  note.
  96  *
  97  *  \subsection SSec_AVRDude AVRDUDE (Windows, Mac, Linux)
  98  *
  99  *  AVRDude is a free, cross-platform and open source command line programmer for Atmel and third party AVR
 100  *  programmers. It is available on the the Windows platform as part of the "WinAVR" package, or on other systems
 101  *  either from a build from the official source code, or in many distributions as a precompiled binary package.
 102  *
 103  *  To load a new HEX file with AVRDude, specify "AVR109" as the programmer, with the allocated COM port. On Windows
 104  *  platforms this will be a COMx port name:
 105  *  \code
 106  *  avrdude -c AVR109 -p at90usb1287 -P COM0 -U flash:w:Mouse.hex
 107  *  \endcode
 108  *
 109  *  On Linux systems, this will typically be a /dev/ttyACMx port name:
 110  *  \code
 111  *  avrdude -c AVR109 -p at90usb1287 -P /dev/ttyACM0 -U flash:w:Mouse.hex
 112  *  \endcode
 113  *
 114  *  Refer to the AVRDude project documentation for additional usage instructions.
 115  *
 116  *  \section Sec_API User Application API
 117  *
 118  *  Several user application functions for FLASH and other special memory area manipulations are exposed by the bootloader,
 119  *  allowing the user application to call into the bootloader at runtime to read and write FLASH data.
 120  *
 121  *  By default, the bootloader API jump table is located 32 bytes from the end of the device's FLASH memory, and follows the
 122  *  following layout:
 123  *
 124  *  \code
 125  *  #define BOOTLOADER_API_TABLE_SIZE          32
 126  *  #define BOOTLOADER_API_TABLE_START         ((FLASHEND + 1UL) - BOOTLOADER_API_TABLE_SIZE)
 127  *  #define BOOTLOADER_API_CALL(Index)         (void*)((BOOTLOADER_API_TABLE_START + (Index * 2)) / 2)
 128  *
 129  *  void    (*BootloaderAPI_ErasePage)(uint32_t Address)               = BOOTLOADER_API_CALL(0);
 130  *  void    (*BootloaderAPI_WritePage)(uint32_t Address)               = BOOTLOADER_API_CALL(1);
 131  *  void    (*BootloaderAPI_FillWord)(uint32_t Address, uint16_t Word) = BOOTLOADER_API_CALL(2);
 132  *  uint8_t (*BootloaderAPI_ReadSignature)(uint16_t Address)           = BOOTLOADER_API_CALL(3);
 133  *  uint8_t (*BootloaderAPI_ReadFuse)(uint16_t Address)                = BOOTLOADER_API_CALL(4);
 134  *  uint8_t (*BootloaderAPI_ReadLock)(void)                            = BOOTLOADER_API_CALL(5);
 135  *  void    (*BootloaderAPI_WriteLock)(uint8_t LockBits)               = BOOTLOADER_API_CALL(6);
 136  *
 137  *  #define BOOTLOADER_MAGIC_SIGNATURE_START   (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 2))
 138  *  #define BOOTLOADER_MAGIC_SIGNATURE         0xDCFB
 139  *
 140  *  #define BOOTLOADER_CLASS_SIGNATURE_START   (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 4))
 141  *  #define BOOTLOADER_CDC_SIGNATURE           0xDF00
 142  *
 143  *  #define BOOTLOADER_ADDRESS_START           (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 8))
 144  *  #define BOOTLOADER_ADDRESS_LENGTH          4
 145  *  \endcode
 146  *
 147  *  From the application the API support of the bootloader can be detected by reading the FLASH memory bytes located at address
 148  *  \c BOOTLOADER_MAGIC_SIGNATURE_START and comparing them to the value \c BOOTLOADER_MAGIC_SIGNATURE. The class of bootloader
 149  *  can be determined by reading the FLASH memory bytes located at address \c BOOTLOADER_CLASS_SIGNATURE_START and comparing them
 150  *  to the value \c BOOTLOADER_CDC_SIGNATURE. The start address of the bootloader can be retrieved by reading the bytes of FLASH
 151  *  memory starting from address \c BOOTLOADER_ADDRESS_START.
 152  *
 153  *  \subsection SSec_API_MemLayout Device Memory Map
 154  *  The following illustration indicates the final memory map of the device when loaded with the bootloader.
 155  *
 156  *  \verbatim
 157  *  +----------------------------+ 0x0000
 158  *  |                            |
 159  *  |                            |
 160  *  |                            |
 161  *  |                            |
 162  *  |                            |
 163  *  |                            |
 164  *  |                            |
 165  *  |                            |
 166  *  |      User Application      |
 167  *  |                            |
 168  *  |                            |
 169  *  |                            |
 170  *  |                            |
 171  *  |                            |
 172  *  |                            |
 173  *  |                            |
 174  *  +----------------------------+ FLASHEND - BOOT_SECTION_SIZE
 175  *  |                            |
 176  *  |   Bootloader Application   |
 177  *  | (Not User App. Accessible) |
 178  *  |                            |
 179  *  +----------------------------+ FLASHEND - 96
 180  *  |   API Table Trampolines    |
 181  *  | (Not User App. Accessible) |
 182  *  +----------------------------+ FLASHEND - 32
 183  *  |    Bootloader API Table    |
 184  *  |   (User App. Accessible)   |
 185  *  +----------------------------+ FLASHEND - 8
 186  *  |   Bootloader ID Constants  |
 187  *  |   (User App. Accessible)   |
 188  *  +----------------------------+ FLASHEND
 189  *  \endverbatim
 190  *
 191  *  \section Sec_KnownIssues Known Issues:
 192  *
 193  *  \par On Linux machines, the CDC bootloader is unstable or inaccessible.
 194  *  A change to the \c ModemManager module in many Linux distributions causes
 195  *  this module to try to take control over inserted CDC devices, corrupting the
 196  *  datastream. A UDEV rule is required to prevent this.
 197  *  See <a href=https://groups.google.com/d/msg/lufa-support/CP9cy2bc8yo/kBqsOu-RBeMJ>here</a> for resolution steps.
 198  *  If the issue still persists then uninstall modemmanager by executing <tt>sudo apt-get remove modemmanager</tt>, or
 199  *  the equivalent using your chosen distribution's package manager.
 200  *
 201  *  \par On Linux machines, the CDC bootloader is inaccessible.
 202  *  On many Linux systems, non-root users do not have automatic access to newly
 203  *  inserted CDC devices. Root privileges or a UDEV rule is required to gain
 204  *  access.
 205  *  See <a href=https://groups.google.com/d/msg/lufa-support/CP9cy2bc8yo/kBqsOu-RBeMJ>here</a> for resolution steps.
 206  *
 207  *  \section Sec_Options Project Options
 208  *
 209  *  The following defines can be found in this demo, which can control the demo behaviour when defined, or changed in value.
 210  *
 211  *  <table>
 212  *   <tr>
 213  *    <th><b>Define Name:</b></th>
 214  *    <th><b>Location:</b></th>
 215  *    <th><b>Description:</b></th>
 216  *   </tr>
 217  *   <tr>
 218  *    <td>NO_BLOCK_SUPPORT</td>
 219  *    <td>AppConfig.h</td>
 220  *    <td>Define to disable memory block read/write support in the bootloader, requiring all reads and writes to be made
 221  *        using the byte-level commands.</td>
 222  *   </tr>
 223  *   <tr>
 224  *    <td>NO_EEPROM_BYTE_SUPPORT</td>
 225  *    <td>AppConfig.h</td>
 226  *    <td>Define to disable EEPROM memory byte read/write support in the bootloader, requiring all EEPROM reads and writes
 227  *        to be made using the block-level commands.</td>
 228  *   </tr>
 229  *   <tr>
 230  *    <td>NO_FLASH_BYTE_SUPPORT</td>
 231  *    <td>AppConfig.h</td>
 232  *    <td>Define to disable FLASH memory byte read/write support in the bootloader, requiring all FLASH reads and writes
 233  *        to be made using the block-level commands.</td>
 234  *   </tr>
 235  *   <tr>
 236  *    <td>NO_LOCK_BYTE_WRITE_SUPPORT</td>
 237  *    <td>AppConfig.h</td>
 238  *    <td>Define to disable lock byte write support in the bootloader, preventing the lock bits from being set programmatically.</td>
 239  *   </tr>
 240  *  </table>
 241  */
 242