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_Installation Driver Installation
  61  *
  62  *  After running this bootloader for the first time on a new computer, you will need to supply the .INF
  63  *  file located in this bootloader project's directory as the device's driver when running under Windows.
  64  *  This will enable Windows to use its inbuilt CDC drivers, negating the need for custom drivers for the
  65  *  device. Other Operating Systems should automatically use their own inbuilt CDC-ACM drivers.
  66  *
  67  *  \section Sec_HostApp Host Controller Application
  68  *
  69  *  This bootloader is compatible with the open source application AVRDUDE, Atmel's AVRPROG, or other
  70  *  applications implementing the AVR109 protocol, which is documented on the Atmel website as an application
  71  *  note.
  72  *
  73  *  \subsection SSec_AVRDude AVRDUDE (Windows, Mac, Linux)
  74  *
  75  *  AVRDude is a free, cross-platform and open source command line programmer for Atmel and third party AVR
  76  *  programmers. It is available on the the Windows platform as part of the "WinAVR" package, or on other systems
  77  *  either from a build from the official source code, or in many distributions as a precompiled binary package.
  78  *
  79  *  To load a new HEX file with AVRDude, specify "AVR109" as the programmer, with the allocated COM port. On Windows
  80  *  platforms this will be a COMx port name:
  81  *  \code
  82  *  avrdude -c AVR109 -p at90usb1287 -P COM0 -U flash:w:Mouse.hex
  83  *  \endcode
  84  *
  85  *  On Linux systems, this will typically be a /dev/ttyACMx port name:
  86  *  \code
  87  *  avrdude -c AVR109 -p at90usb1287 -P /dev/ttyACM0 -U flash:w:Mouse.hex
  88  *  \endcode
  89  *
  90  *  Refer to the AVRDude project documentation for additional usage instructions.
  91  *
  92  *  \section Sec_API User Application API
  93  *
  94  *  Several user application functions for FLASH and other special memory area manipulations are exposed by the bootloader,
  95  *  allowing the user application to call into the bootloader at runtime to read and write FLASH data.
  96  *
  97  *  By default, the bootloader API jump table is located 32 bytes from the end of the device's FLASH memory, and follows the
  98  *  following layout:
  99  *
 100  *  \code
 101  *  #define BOOTLOADER_API_TABLE_SIZE          32
 102  *  #define BOOTLOADER_API_TABLE_START         ((FLASHEND + 1UL) - BOOTLOADER_API_TABLE_SIZE)
 103  *  #define BOOTLOADER_API_CALL(Index)         (void*)((BOOTLOADER_API_TABLE_START + (Index * 2)) / 2)
 104  *
 105  *  void    (*BootloaderAPI_ErasePage)(uint32_t Address)               = BOOTLOADER_API_CALL(0);
 106  *  void    (*BootloaderAPI_WritePage)(uint32_t Address)               = BOOTLOADER_API_CALL(1);
 107  *  void    (*BootloaderAPI_FillWord)(uint32_t Address, uint16_t Word) = BOOTLOADER_API_CALL(2);
 108  *  uint8_t (*BootloaderAPI_ReadSignature)(uint16_t Address)           = BOOTLOADER_API_CALL(3);
 109  *  uint8_t (*BootloaderAPI_ReadFuse)(uint16_t Address)                = BOOTLOADER_API_CALL(4);
 110  *  uint8_t (*BootloaderAPI_ReadLock)(void)                            = BOOTLOADER_API_CALL(5);
 111  *  void    (*BootloaderAPI_WriteLock)(uint8_t LockBits)               = BOOTLOADER_API_CALL(6);
 112  *
 113  *  #define BOOTLOADER_MAGIC_SIGNATURE_START   (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 2))
 114  *  #define BOOTLOADER_MAGIC_SIGNATURE         0xDCFB
 115  *
 116  *  #define BOOTLOADER_CLASS_SIGNATURE_START   (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 4))
 117  *  #define BOOTLOADER_CDC_SIGNATURE           0xDF00
 118  *
 119  *  #define BOOTLOADER_ADDRESS_START           (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 8))
 120  *  #define BOOTLOADER_ADDRESS_LENGTH          4
 121  *  \endcode
 122  *
 123  *  From the application the API support of the bootloader can be detected by reading the FLASH memory bytes located at address
 124  *  \c BOOTLOADER_MAGIC_SIGNATURE_START and comparing them to the value \c BOOTLOADER_MAGIC_SIGNATURE. The class of bootloader
 125  *  can be determined by reading the FLASH memory bytes located at address \c BOOTLOADER_CLASS_SIGNATURE_START and comparing them
 126  *  to the value \c BOOTLOADER_CDC_SIGNATURE. The start address of the bootloader can be retrieved by reading the bytes of FLASH
 127  *  memory starting from address \c BOOTLOADER_ADDRESS_START.
 128  *
 129  *  \subsection SSec_API_MemLayout Device Memory Map
 130  *  The following illustration indicates the final memory map of the device when loaded with the bootloader.
 131  *
 132  *  \verbatim
 133  *  +----------------------------+ 0x0000
 134  *  |                            |
 135  *  |                            |
 136  *  |                            |
 137  *  |                            |
 138  *  |                            |
 139  *  |                            |
 140  *  |                            |
 141  *  |                            |
 142  *  |      User Application      |
 143  *  |                            |
 144  *  |                            |
 145  *  |                            |
 146  *  |                            |
 147  *  |                            |
 148  *  |                            |
 149  *  |                            |
 150  *  +----------------------------+ FLASHEND - BOOT_SECTION_SIZE
 151  *  |                            |
 152  *  |   Bootloader Application   |
 153  *  | (Not User App. Accessible) |
 154  *  |                            |
 155  *  +----------------------------+ FLASHEND - 96
 156  *  |   API Table Trampolines    |
 157  *  | (Not User App. Accessible) |
 158  *  +----------------------------+ FLASHEND - 32
 159  *  |    Bootloader API Table    |
 160  *  |   (User App. Accessible)   |
 161  *  +----------------------------+ FLASHEND - 8
 162  *  |   Bootloader ID Constants  |
 163  *  |   (User App. Accessible)   |
 164  *  +----------------------------+ FLASHEND
 165  *  \endverbatim
 166  *
 167  *  \section Sec_KnownIssues Known Issues:
 168  *
 169  *  \par On Linux machines, the CDC bootloader is unstable or inaccessible.
 170  *  A change to the \c ModemManager module in many Linux distributions causes
 171  *  this module to try to take control over inserted CDC devices, corrupting the
 172  *  datastream. A UDEV rule is required to prevent this.
 173  *  See <a href=https://groups.google.com/d/msg/lufa-support/CP9cy2bc8yo/kBqsOu-RBeMJ>here</a> for resolution steps.
 174  *
 175  *  \par On Linux machines, the CDC bootloader is inaccessible.
 176  *  On many Linux systems, non-root users do not have automatic access to newly
 177  *  inserted CDC devices. Root privileges or a UDEV rule is required to gain
 178  *  access.
 179  *  See <a href=https://groups.google.com/d/msg/lufa-support/CP9cy2bc8yo/kBqsOu-RBeMJ>here</a> for resolution steps.
 180  *
 181  *  \par After loading an application, it is not run automatically on startup.
 182  *  Some USB AVR boards ship with the BOOTRST fuse set, causing the bootloader
 183  *  to run automatically when the device is reset. In most cases, the BOOTRST
 184  *  fuse should be disabled and the HWBE fuse used instead to run the bootloader
 185  *  when needed.
 186  *
 187  *  \section Sec_Options Project Options
 188  *
 189  *  The following defines can be found in this demo, which can control the demo behaviour when defined, or changed in value.
 190  *
 191  *  <table>
 192  *   <tr>
 193  *    <th><b>Define Name:</b></th>
 194  *    <th><b>Location:</b></th>
 195  *    <th><b>Description:</b></th>
 196  *   </tr>
 197  *   <tr>
 198  *    <td>NO_BLOCK_SUPPORT</td>
 199  *    <td>AppConfig.h</td>
 200  *    <td>Define to disable memory block read/write support in the bootloader, requiring all reads and writes to be made
 201  *        using the byte-level commands.</td>
 202  *   </tr>
 203  *   <tr>
 204  *    <td>NO_EEPROM_BYTE_SUPPORT</td>
 205  *    <td>AppConfig.h</td>
 206  *    <td>Define to disable EEPROM memory byte read/write support in the bootloader, requiring all EEPROM reads and writes
 207  *        to be made using the block-level commands.</td>
 208  *   </tr>
 209  *   <tr>
 210  *    <td>NO_FLASH_BYTE_SUPPORT</td>
 211  *    <td>AppConfig.h</td>
 212  *    <td>Define to disable FLASH memory byte read/write support in the bootloader, requiring all FLASH reads and writes
 213  *        to be made using the block-level commands.</td>
 214  *   </tr>
 215  *   <tr>
 216  *    <td>NO_LOCK_BYTE_WRITE_SUPPORT</td>
 217  *    <td>AppConfig.h</td>
 218  *    <td>Define to disable lock byte write support in the bootloader, preventing the lock bits from being set programmatically.</td>
 219  *   </tr>
 220  *  </table>
 221  */
 222