X-Git-Url: http://git.linex4red.de/pub/lufa.git/blobdiff_plain/c31fdbd03eee95660d65adb0f1bf7c0c397fd435..refs/heads/master:/Bootloaders/CDC/BootloaderCDC.txt diff --git a/Bootloaders/CDC/BootloaderCDC.txt b/Bootloaders/CDC/BootloaderCDC.txt index e88a7fba8..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 @@ -111,12 +138,18 @@ * #define BOOTLOADER_MAGIC_SIGNATURE 0xDCFB * * #define BOOTLOADER_CLASS_SIGNATURE_START (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 4)) - * #define BOOTLOADER_CDC_SIGNATURE 0xCDC1 + * #define BOOTLOADER_CDC_SIGNATURE 0xDF00 * * #define BOOTLOADER_ADDRESS_START (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 8)) * #define BOOTLOADER_ADDRESS_LENGTH 4 * \endcode * + * 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. * @@ -155,11 +188,21 @@ * +----------------------------+ FLASHEND * \endverbatim * - * 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. + * \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 * @@ -167,31 +210,31 @@ * * * - * - * - * + * + * + * * * * - * + * * * * * - * + * * * * * - * + * * * * * - * + * * * *
Define Name:Location:Description:Define Name:Location:Description:
NO_BLOCK_SUPPORTMakefile LUFA_OPTSAppConfig.hDefine to disable memory block read/write support in the bootloader, requiring all reads and writes to be made * using the byte-level commands.
NO_EEPROM_BYTE_SUPPORTMakefile LUFA_OPTSAppConfig.hDefine to disable EEPROM memory byte read/write support in the bootloader, requiring all EEPROM reads and writes * to be made using the block-level commands.
NO_FLASH_BYTE_SUPPORTMakefile LUFA_OPTSAppConfig.hDefine to disable FLASH memory byte read/write support in the bootloader, requiring all FLASH reads and writes * to be made using the block-level commands.
NO_LOCK_BYTE_WRITE_SUPPORTMakefile LUFA_OPTSAppConfig.hDefine to disable lock byte write support in the bootloader, preventing the lock bits from being set programmatically.