X-Git-Url: http://git.linex4red.de/pub/lufa.git/blobdiff_plain/40fd566dbaa76b1b40677cc826da2e89af424aa2..refs/heads/master:/Bootloaders/CDC/BootloaderCDC.txt

diff --git a/Bootloaders/CDC/BootloaderCDC.txt b/Bootloaders/CDC/BootloaderCDC.txt
index 9abd7b2f8..f8c349cde 100644
--- a/Bootloaders/CDC/BootloaderCDC.txt
+++ b/Bootloaders/CDC/BootloaderCDC.txt
@@ -10,10 +10,10 @@
  *
  *  The following list indicates what microcontrollers are compatible with this demo.
  *
- *  - Series 7 USB AVRs (AT90USBxxx7)
- *  - Series 6 USB AVRs (AT90USBxxx6)
- *  - Series 4 USB AVRs (ATMEGAxxU4)
- *  - Series 2 USB AVRs (AT90USBxx2, ATMEGAxxU2)
+ *  \li Series 7 USB AVRs (AT90USBxxx7)
+ *  \li Series 6 USB AVRs (AT90USBxxx6)
+ *  \li Series 4 USB AVRs (ATMEGAxxU4)
+ *  \li Series 2 USB AVRs (AT90USBxx2, ATMEGAxxU2)
  *
  *  \section Sec_Info USB Information:
  *
@@ -37,7 +37,7 @@
  *    <td>USBIF CDC Class Standard</td>
  *   </tr>
  *   <tr>
- *    <td><b>Usable Speeds:</b></td>
+ *    <td><b>Supported USB Speeds:</b></td>
  *    <td>Full Speed Mode</td>
  *   </tr>
  *  </table>
@@ -54,6 +54,33 @@
  *  When the bootloader is running, the board's LED(s) will flash at regular intervals to distinguish the
  *  bootloader from the normal user application.
  *
+ *  \warning <b>THIS BOOTLOADER IS NOT SECURE.</b> Malicious entities can recover written data, even if the device
+ *           lockbits are set.
+ *
+ *  \section Sec_Running Running the Bootloader
+ *
+ *  On the USB AVR8 devices, setting the \c HWBE device fuse will cause the bootloader to run if the \c HWB pin of
+ *  the AVR is grounded when the device is reset.
+ *
+ *  The are two behaviours of this bootloader, depending on the device's fuses:
+ *
+ *  <b>If the device's BOOTRST fuse is set</b>, the bootloader will run any time the system is reset from
+ *  the external reset pin, unless no valid user application has been loaded. To initiate the bootloader, the
+ *  device's external reset pin should be grounded momentarily.
+ *
+ *  <b>If the device's BOOTRST fuse is not set</b>, the bootloader will run only if initiated via a software
+ *  jump, or if the \c HWB pin was low during the last device reset (if the \c HWBE fuse is set).
+ *
+ *  For board specific exceptions to the above, see below.
+ *
+ *  \subsection SSec_XPLAIN Atmel Xplain Board
+ *  Ground the USB AVR JTAG's \c TCK pin to ground when powering on the board to start the bootloader. This assumes the
+ *  \c HWBE fuse is cleared and the \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board.
+ *
+ *  \subsection SSec_Leonardo Arduino Leonardo Board
+ *  Ground \c IO13 when powering the board to start the bootloader. This assumes the \c HWBE fuse is cleared and the
+ *  \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board.
+ *
  *  \section Sec_Installation Driver Installation
  *
  *  After running this bootloader for the first time on a new computer, you will need to supply the .INF
@@ -95,7 +122,9 @@
  *  following layout:
  *
  *  \code
- *  #define BOOTLOADER_API_CALL(Index)        (void*)(((FLASHEND - 32) + (2 * Index)) / 2)
+ *  #define BOOTLOADER_API_TABLE_SIZE          32
+ *  #define BOOTLOADER_API_TABLE_START         ((FLASHEND + 1UL) - BOOTLOADER_API_TABLE_SIZE)
+ *  #define BOOTLOADER_API_CALL(Index)         (void*)((BOOTLOADER_API_TABLE_START + (Index * 2)) / 2)
  *
  *  void    (*BootloaderAPI_ErasePage)(uint32_t Address)               = BOOTLOADER_API_CALL(0);
  *  void    (*BootloaderAPI_WritePage)(uint32_t Address)               = BOOTLOADER_API_CALL(1);
@@ -105,21 +134,75 @@
  *  uint8_t (*BootloaderAPI_ReadLock)(void)                            = BOOTLOADER_API_CALL(5);
  *  void    (*BootloaderAPI_WriteLock)(uint8_t LockBits)               = BOOTLOADER_API_CALL(6);
  *
- *  #define BOOTLOADER_MAGIC_SIGNATURE_START   (FLASHEND - 2)
+ *  #define BOOTLOADER_MAGIC_SIGNATURE_START   (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 2))
  *  #define BOOTLOADER_MAGIC_SIGNATURE         0xDCFB
  *
- *  #define BOOTLOADER_CLASS_SIGNATURE_START   (FLASHEND - 4)
- *  #define BOOTLOADER_CDC_SIGNATURE           0xCDC1
+ *  #define BOOTLOADER_CLASS_SIGNATURE_START   (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 4))
+ *  #define BOOTLOADER_CDC_SIGNATURE           0xDF00
  *
- *  #define BOOTLOADER_ADDRESS_START           (FLASHEND - 8)
+ *  #define BOOTLOADER_ADDRESS_START           (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 8))
  *  #define BOOTLOADER_ADDRESS_LENGTH          4
  *  \endcode
  *
- *  Bootloaders reporting a device release revision number of 1.00 or greater are bootloader API enabled. From the application
- *  the API support of the bootloader can be detected by reading the FLASH memory bytes located at address \c BOOTLOADER_MAGIC_SIGNATURE_START
- *  and comparing them to the value \c BOOTLOADER_MAGIC_SIGNATURE. The class of bootloader can be determined by reading the
- *  FLASH memory bytes located at address \c BOOTLOADER_CLASS_SIGNATURE_START and comparing them to the value \c BOOTLOADER_CDC_SIGNATURE.
- *  The start address of the bootloader can be retrieved by reading the bytes of FLASH memory starting from address \c BOOTLOADER_ADDRESS_START.
+ *  From the application the API support of the bootloader can be detected by reading the FLASH memory bytes located at address
+ *  \c BOOTLOADER_MAGIC_SIGNATURE_START and comparing them to the value \c BOOTLOADER_MAGIC_SIGNATURE. The class of bootloader
+ *  can be determined by reading the FLASH memory bytes located at address \c BOOTLOADER_CLASS_SIGNATURE_START and comparing them
+ *  to the value \c BOOTLOADER_CDC_SIGNATURE. The start address of the bootloader can be retrieved by reading the bytes of FLASH
+ *  memory starting from address \c BOOTLOADER_ADDRESS_START.
+ *
+ *  \subsection SSec_API_MemLayout Device Memory Map
+ *  The following illustration indicates the final memory map of the device when loaded with the bootloader.
+ *
+ *  \verbatim
+ *  +----------------------------+ 0x0000
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |      User Application      |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  |                            |
+ *  +----------------------------+ FLASHEND - BOOT_SECTION_SIZE
+ *  |                            |
+ *  |   Bootloader Application   |
+ *  | (Not User App. Accessible) |
+ *  |                            |
+ *  +----------------------------+ FLASHEND - 96
+ *  |   API Table Trampolines    |
+ *  | (Not User App. Accessible) |
+ *  +----------------------------+ FLASHEND - 32
+ *  |    Bootloader API Table    |
+ *  |   (User App. Accessible)   |
+ *  +----------------------------+ FLASHEND - 8
+ *  |   Bootloader ID Constants  |
+ *  |   (User App. Accessible)   |
+ *  +----------------------------+ FLASHEND
+ *  \endverbatim
+ *
+ *  \section Sec_KnownIssues Known Issues:
+ *
+ *  \par On Linux machines, the CDC bootloader is unstable or inaccessible.
+ *  A change to the \c ModemManager module in many Linux distributions causes
+ *  this module to try to take control over inserted CDC devices, corrupting the
+ *  datastream. A UDEV rule is required to prevent this.
+ *  See <a href=https://groups.google.com/d/msg/lufa-support/CP9cy2bc8yo/kBqsOu-RBeMJ>here</a> for resolution steps.
+ *  If the issue still persists then uninstall modemmanager by executing <tt>sudo apt-get remove modemmanager</tt>, or
+ *  the equivalent using your chosen distribution's package manager.
+ *
+ *  \par On Linux machines, the CDC bootloader is inaccessible.
+ *  On many Linux systems, non-root users do not have automatic access to newly
+ *  inserted CDC devices. Root privileges or a UDEV rule is required to gain
+ *  access.
+ *  See <a href=https://groups.google.com/d/msg/lufa-support/CP9cy2bc8yo/kBqsOu-RBeMJ>here</a> for resolution steps.
  *
  *  \section Sec_Options Project Options
  *
@@ -127,9 +210,9 @@
  *
  *  <table>
  *   <tr>
- *    <td><b>Define Name:</b></td>
- *    <td><b>Location:</b></td>
- *    <td><b>Description:</b></td>
+ *    <th><b>Define Name:</b></th>
+ *    <th><b>Location:</b></th>
+ *    <th><b>Description:</b></th>
  *   </tr>
  *   <tr>
  *    <td>NO_BLOCK_SUPPORT</td>