Initial Refleks Lite hardware and firmware release

arcadestick_software/DFU.md

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+# Refleks Lite Bootloader and DFU Guide
+
+## Flash layout
+
+| Region | Start address | Size | USB identity |
+| --- | ---: | ---: | --- |
+| Bootloader / DFU | `0x08000000` | 24 KB | `1209:E667` |
+| App1 / XInput | `0x08006000` | 52 KB | `1209:E668` |
+| App2 / DInput | `0x08013000` | 52 KB | `1209:E669` |
+
+For initial programming, flash `build/Release/arcadestick_full.hex` with an
+ST-Link. This file contains the bootloader and both applications.
+
+## Boot selection
+
+- Hold `START` during reset to keep the device in DFU mode.
+- When `PA4` is LOW, the bootloader starts XInput App1.
+- When `PA5` is LOW, the bootloader starts DInput App2.
+- If the selection is invalid, or the selected application's vector table is
+  invalid, the bootloader remains in DFU mode.
+
+## Updating over USB
+
+The bootloader implements standard USB DFU 1.1. It does not use DfuSe address
+commands; the alternate interface number selects the destination slot.
+
+```powershell
+# XInput App1
+dfu-util -d 1209:e667 -a 0 -D build/Release/arcadestick_xinput.bin
+
+# DInput App2
+dfu-util -d 1209:e667 -a 1 -D build/Release/arcadestick.bin
+```
+
+On Windows, the `1209:E667` device must use the WinUSB driver. `dfu-util` is
+not currently installed in this computer's `PATH`.