For all information relevant to the status of the current OpenDingux Beta please see the link below. It is maintained by actual developers. I am simply posting a guide of how I personally installed OpenDingux on to my RS90 using Windows as an end-user.https://boards.dingoonity.org/ingenic-jz4760-devices/state-of-opendingux-beta/
Intro: The process has been streamlined so, this guide will be much shorter than it was previously. The following steps should allow you to install the OpenDingux Beta to the RS90 and RG99. If you with to flash OpenDingux to other compatible devices, please see my notes following the guide. I own nothing, and the risk is entirely yours.
Edit (10-7-21) Changed notes regarding Lepus in the last section.
Edit (10-4-21) Updating the guide to reflect current methods and software upgrades.
Edit (1-8-21) Just a couple of minor updates reflecting the current state of OD.
Edit (6-1-19) Running the current update OPK once you have OpenDingux completely installed will allow you to access the internal memory via USB. FTP access is no longer required.
Edit (5-17-19) More hardware versions are now supported with the current version of OpenDingux, and installing from Windows should be reasonably painless. I have upgraded the guide slightly to reflect the update.
1. With the unit powered off plug the unit in to your computer via a USB cable.
2. Power the RS-90 on while holding the "A" button to get the unit into the USB boot mode. (Same method, but hold "START" on the RG99. Be warned, the device will vibrate through the entire process.) The button may be different on your device to get it in to boot mode.
3. At this point you will need to install a driver specific to the device. Run an app called Zadig found in the link below. With your device in boot mode, you can select the driver you need from the drop down menu. Zadig can be found here. https://zadig.akeo.ie/
4. From the link below download and extract the "odboot-client-windows" file. Please note that you will need to be logged in to Github to download this file. https://github.com/OpenDingux/buildroot/actions/runs/1295966734
5. Download the latest build of OpenDingux for the RS90 at the link below.http://od.abstraction.se/opendingux/latest/
6. At this point just drag and drop the RS90 update opk file on top of the odboot-client file you extracted and a prompt should appear giving you options to install. If you are unsure of which RS90 device you have, start with the first, and use the second if that fails.
7. Follow the prompts to install OpenDingux to your device.
8. Once this is done you can use a "fat32" formatted micro sd card to store your roms or additional files.
9. At this point you can put "OPK" files for the RS-90 in the app folder internally, and they will appear on the unit ready to use. (Please note OPK files from other systems will not work. They must be compiled for the RS-90.)
10. Future updates can be installed by simply running an update OPK found at the site linked here.http://od.abstraction.se/opendingux/latest/
Followup notes regarding other OpenDingux Devices:
The methods in this guide will work to install OpenDingux on most of the currently supported devices. The only differences being the manner of getting in to boot mode, and making sure that you download the Beta OPK specific to your device. If you wish to use this guide to install to other devices, please see the specifics below.
Lepus: J4760(B) Devices.: Putting the device in boot mode is as simple as inserting a blank SD in to the OS card slot, powering the unit on and plugging it in to your PC. SD cards were previously unreliable when it came to flashing, but that has improved. However if you have problems flashing to a specific card, trying a second card may be worth your while.
GCW0: JZ4770 Devices: In my experience these devices offer the most pleasant experience on the current Beta. Button combinations are likely to vary, but to put my RG350M in to boot mode I held "SELECT" on boot. Keep in mind that for these devices while a fresh flash of the Beta is considered ideal you can simply download the latest nightly on to a stock OS SD and update to the Beta via the latest OPK update.