Add D01 fpga firmware dump and update doc

iidx/README.md

@@ -1,4 +1,4 @@
 # Beatmania IIDX supplements
-* [ezusb](ezusb/README.md): Drivers and firmware binaries for a real ezusb (C02) IO board.
+* [ezusb](ezusb/README.md): Drivers and firmware binaries for a real ezusb (C02/D01) IO board.
 * [ezusb2](ezusb2/README.md): Drivers and firmware binaries for a real ezusb FX2 (IO2) IO board.
 * [misc](misc/README.md): Various stuff. Check readme.

iidx/ezusb/README.md

@@ -1,3 +1,3 @@
-# Ezusb (legacy), aka C02 IO
+# Ezusb (legacy): C02 and D01 IO
 * [driver](driver/README.md): Drivers for various platforms.
 * [firmware](firmware/README.md): Firmware binary blobs required by the games.

iidx/ezusb/firmware/README.md

@@ -1,9 +1,18 @@
-# Firmware binaries Ezusb (legacy), aka C02 IO
+# Firmware binaries Ezusb (legacy): C02 and D01 IO
 Firmware binary blobs. Requires appropriate tools from BT5 to load them to the
 hardware. There are two revisions of firmware images, **v1** and **v2**. 
 
-v1 was used on IIDX 9 to 13 and v2 on IIDX 14 to 24. It does not matter
-which revision of the base firmware and FPGA image (always in combination!) are
-used when running the real hardware with BT5. Still, we recommend using the v2
-binaries as they are, from a development standpoint, the latest "update". Do
-*NOT* mix v1 and v2 binaries.
+Firmware types:
+* `ezusb_XX.bin`: Base firmware which always needs to be uploaded to the board first.
+* `fpga_XX.bin`: FPGA firmware, needs to be uploaded after the base firmware.
+* `sram.bin`: SRAM dump with contents that need to be uploaded as well, only
+relevant when using **v2** files.
+
+**v1** was used on IIDX 9 to 13 and **v2** on IIDX 14 to 24. It does not matter
+which revision of the base firmware and FPGA image as long as you do not mix
+different versions.
+
+Still, we recommend using the **v2** binaries as they are, from a development
+standpoint, the latest "update".
+
+Exception for D01 boards: Use the `ezusb_v1.bin` and `fpga_v1.bin`, only.