X-Git-Url: http://git.linex4red.de/pub/lufa.git/blobdiff_plain/f8a1dc7424cd83f2f3e87274010d379a661b76e4..refs/heads/master:/Bootloaders/CDC/BootloaderCDC.txt diff --git a/Bootloaders/CDC/BootloaderCDC.txt b/Bootloaders/CDC/BootloaderCDC.txt index b087bd575..f8c349cde 100644 --- a/Bootloaders/CDC/BootloaderCDC.txt +++ b/Bootloaders/CDC/BootloaderCDC.txt @@ -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 THIS BOOTLOADER IS NOT SECURE. 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: + * + * If the device's BOOTRST fuse is set, 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. + * + * If the device's BOOTRST fuse is not set, 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 @@ -161,15 +188,31 @@ * +----------------------------+ 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 here for resolution steps. + * If the issue still persists then uninstall modemmanager by executing sudo apt-get remove modemmanager, 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 here for resolution steps. + * * \section Sec_Options Project Options * * The following defines can be found in this demo, which can control the demo behaviour when defined, or changed in value. * * * - * - * - * + * + * + * * * *
Define Name:Location:Description:Define Name:Location:Description:
NO_BLOCK_SUPPORT