[Montree]

Need to install older version Rockbox for the dual boot, not the newest one then.

The official supported version of Rockbox for the M3K can boot in the Fiio Firmware if the “Play” button is held down when turning on. Otherwise it boots directly into native Rockbox (very fast!).

The dual version with the choice at the Boot Screen was developed by a user “XVortex” and although it works it has problems and isn’t being worked on now and is regarded as unsupported by the Rockbox community. I don't know if XVortex's files are still available to download.

 

[amachronic]

Due to recent improvements in the Rockbox bootloader I could probably add a graphical dual boot menu now (m3k rockbox dev here). I'll look into that this weekend, maybe.

Not to toot my own horn here, but Rockbox on the M3K is really stable nowadays. There's no serious issues that I know of, and I try to fix any reported problems (sometimes that ends up taking a while but it gets done). The original firmware is a mess, it is very buggy and that affected the stability and usability of XVortex's port.

It's worth mentioning that if you install Rockbox, you both have dual boot support and can easily roll it back to the factory state if you want. Plus, the M3K is basically unbrickable so there's virtually no risk to the install.

 

[Montree]

I am very grateful for amachronic’s work (and others) for their work on Rockbox for the M3K. I have four different players with Rockbox and the M3K is my favourite. It’s also my favourite player overall compared to others I have from Shanling, Hidizs and Tempotec.

 

[noknok23]

now that there is rockbox i really want a m3k, a shame it is discontinued.

 

[AudioMan025]

Has anyone else tried the M3K-FW1.4.5 on it? I did and I ran into some annoyances, so I ended up going back to 1.4.3.

 

[losber]

It still rocks with Rockbox and Aurora theme.
Rockbox installation guide is here https://www.reddit.com/r/rockbox/comments/pbtlrt/fiio_m3k_rockbox_native_port_installation/