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+The source for the hid-flash program in this folder is a deriviative of the
+"cli" modified by Vassilis Serasidis to work with the STM32 Arduino core,
+available here:
+https://github.com/Serasidis/STM32_HID_Bootloader/tree/master/cli
+
+The original source for hid-flash was written by Bruno Freitas, available
+here:
+https://github.com/bootsector/stm32-hid-bootloader/tree/master/cli
+
+This derivative contains the following changes:
+1) The "port" argument is now optional.  If not supplied hid-flash will not
+   attempt to open a serial port and enter the bootloader, it will assume
+   that the device has already entered the bootloader and look for a USB
+   device with the appropriate Vendor and Product IDs. This change allows
+   Klipper's "flash_usb.py" script to enter the bootloader and wait for the
+   mcu to reconnect.
+2) When the serial port is specified, hid-flash will use Klipper's procedure
+   for entering the bootloader (Open the port at 1200 baud and toggle DTR).
+3) The hid-flash program now accepts a command from the bootloader that allows
+   a STM32F103 device to identify itself as a "high-density" device during
+   the flashing process.  This fixes a bug where the final page would not
+   be written if the last portion of the binary was less than or equal to
+   1024 bytes. A forked version of the bootloader is required to send the
+   "high-density" command, however the tool will still work correctly with
+   the original bootloader (sans the bug that affects high density devices).
+4) A typo was fixed where an "if" statement was using an assignment operator
+   to test for equality.
+5) The Makefile was changed to check for the libusb-1.0 dependency. If it
+   does not exist the user will be warned and the build aborted, however
+   no error will be generated.  This allows Klipper's "make FLASH"
+   functionality to work when flashing via DFU without installing the
+   libusb-1.0 dependency for hid-flash.
+
+- Eric Callahan <arksine.code@gmail.com>