rockbox/rbutil/jztool

jztool -- Ingenic device utility & bootloader installer

The jztool utility can help install, backup, and restore the bootloader on Rockbox players based on a supported Ingenic SoC (currently only the X1000).

Running jztool

Getting a bootloader

To use jztool you need to compile or download a bootloader for your player. It's recommended to use only official released bootloaders, since bootloaders compiled from Git are not tested and might be buggy.

You can download released bootloaders from https://download.rockbox.org/.

The bootloader file is named after the target: for example, the FiiO M3K bootloader is called bootloader.m3k. The FiiO M3K is used as an example here, but the instructions apply to all X1000-based players.

Use jztool --help to find out the model name of your player.

Entering USB boot mode

USB boot mode is a low-level mode provided by the CPU which allows a computer to load firmware onto the device. You need to put your player into this mode manually before using jztool (unfortunately, it can't be done automatically.)

To connect the player in USB boot mode, follow these steps:

1. Ensure the player is fully powered off.
2. Plug one end of the USB cable into your player.
3. Hold down your player's USB boot key (see below).
4. Plug the other end of the USB cable into your computer.
5. Let go of the USB boot key.

The USB boot key depends on your player:

• FiiO M3K: Volume Down
• Shanling Q1: Play
• Eros Q: Menu

Linux/Mac

Run the following command in a terminal. Note that on Linux, you will need to have root access to allow libusb to access the USB device.

# Linux / Mac
# NOTE: root permissions are required on Linux to access the USB device
#       eg. with 'sudo' or 'su -c' depending on your distro.
$ ./jztool fiiom3k load bootloader.m3k

Windows

To allow jztool access to your player in USB boot mode, you need to install the WinUSB driver. The recommended way to install it is using Zadig, which may be downloaded from its homepage https://zadig.akeo.ie. Please note this is 3rd party software not maintained or supported by Rockbox developers. (Zadig will require administrator access on the machine you are using.)

When running Zadig you must select the WinUSB driver; the other driver options will not work properly with jztool. You will have to select the correct USB device in Zadig. All X1000-based players use the same USB ID while in USB boot mode, listed below. NOTE: the device name may show only as "X" and a hollow square in Zadig. The IDs will not change, so those are the most reliable way to confirm you have selected the correct device.

Name:   Ingenic Semiconductor Co.,Ltd X1000
USB ID: A108 1000

Assuming you installed the WinUSB driver successfully, open a command prompt in the folder containing jztool. Administrator access is not required for this step.

Type the following command to load the Rockbox bootloader:

# Windows
$ jztool.exe fiiom3k load bootloader.m3k

Using the recovery menu

If jztool runs successfully your player will display the Rockbox bootloader's recovery menu. If you want to permanently install Rockbox to your device, copy the bootloader file you downloaded to the root of your SD card, insert the SD card to your player, and choose "Install/update bootloader" from the menu.

It is highly recommended that you take a backup of your existing bootloader in case of any trouble -- choose "Backup bootloader" from the recovery menu. The backup file is called PLAYER-boot.bin, where PLAYER is the model name. (Example: fiiom3k-boot.bin.)

You can restore the backup later by putting it on the root of your SD card and selecting "Restor bootloader" in the recovery menu.

After installing the Rockbox bootloader, you can access the recovery menu by holding a key while booting:

• FiiO M3K: Volume Up
• Shanling Q1: Next (button on the lower left)
• Eros Q: Volume Up

Known issues

• When using the bootloader's USB mode, you may get stuck on "Waiting for USB" even though the cable is already plugged in. If this occurs, unplug the USB cable and plug it back in to trigger the connection.

TODO list

Add better documentation and logging

There's only a bare minimum of documentation, and logging is sparse, not really enough to debug problems.

Some of the error messages could be friendlier too.

Integration with the Rockbox utility

Adding support to the Rockbox utility should be mostly boilerplate since the jztool library wraps all the troublesome details.

Permissions are an issue on Linux because by default only root can access "raw" USB devices. If we want to package rbutil for distro we can install a udev rule to allow access to the specific USB IDs we need, eg. allowing users in the "wheel" group to access the device.

On Windows and Mac, no special permissions are needed to access USB devices assuming the drivers are set up. (Zadig does require administrator access to run, but that's external to the Rockbox utility.)