X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/f8a1dc7424cd83f2f3e87274010d379a661b76e4..5ba628d10b54d58d445896290ba9799bd76a73b3:/Bootloaders/Printer/BootloaderPrinter.txt

diff --git a/Bootloaders/Printer/BootloaderPrinter.txt b/Bootloaders/Printer/BootloaderPrinter.txt
index 01237fd59..d9aa79686 100644
--- a/Bootloaders/Printer/BootloaderPrinter.txt
+++ b/Bootloaders/Printer/BootloaderPrinter.txt
@@ -54,6 +54,30 @@
  *  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
@@ -154,6 +178,15 @@
  *  +----------------------------+ FLASHEND
  *  \endverbatim
  *
+ *
+ *  \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
  *
  *  The following defines can be found in this demo, which can control the demo behaviour when defined, or changed in value.