X-Git-Url: http://git.linex4red.de/pub/lufa.git/blobdiff_plain/6e0baf434221f76ab3faab226128c3ccf3007bf9..refs/heads/master:/Bootloaders/CDC/BootloaderCDC.txt diff --git a/Bootloaders/CDC/BootloaderCDC.txt b/Bootloaders/CDC/BootloaderCDC.txt index 5a3581d1b..f8c349cde 100644 --- a/Bootloaders/CDC/BootloaderCDC.txt +++ b/Bootloaders/CDC/BootloaderCDC.txt @@ -57,6 +57,30 @@ * \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 @@ -171,7 +195,8 @@ * 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 \c sudo \c apt-get \c remove \c modemmanager + * 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 @@ -179,12 +204,6 @@ * access. * See here for resolution steps. * - * \par After loading an application, it is not run automatically on startup. - * Some USB AVR boards ship with the BOOTRST fuse set, causing the bootloader - * to run automatically when the device is reset. In most cases, the BOOTRST - * fuse should be disabled and the HWBE fuse used instead to run the bootloader - * when needed. - * * \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.