* When the bootloader is running, the board's LED(s) will flash at regular intervals to distinguish the
* bootloader from the normal user application.
*
+ * \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
*
* This bootloader uses the Generic Text-Only printer drivers inbuilt into all modern operating systems, thus no
* #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_PRINTER_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.
*
* +----------------------------+ 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_PRINTER_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, new firmware fails to be sent to the device via CUPS.
+ * Only a limited subset of normal printer functionality is exposed via the
+ * bootloader, causing CUPS to reject print requests from applications that
+ * are unable to handle true plain-text printing. For best results, the low
+ * level \c lpr command should be used to print new firmware to the bootloader.
*
* \section Sec_Options Project Options
*
projects / pub / lufa.git / blobdiff