Rockbox for Oakcastle MP100

[MaxRoverForever]

Hi! I was curious if a small, cheap player such as the Oakcastle MP100 is capable of running Rockbox, or just if the Oakcastle MP100 has updatable firmware. I have one of these and I would really like to see what its OS looks like on the inside.

[saratoga]

Open it up and see what CPU it uses.

[MaxRoverForever]

Yeah, um, there are no visible screws or seams, I'm not sure how to open it. I don't want to break either.

[speachy]

The manual includes an FCC ID, which can be used to look up the device on the FCC web site, notably including internal photos that clearly show "2127" markings on one of the ASICs.

In other words, this is an Actions ATJ2127, which has an order of magnitude too little RAM for Rockbox.

[MaxRoverForever]

Dude.
You are a f***ing genius.
Could you speculate on the boot process of the device at all, or the specs (what the bootloader loads from)? If I can't do rockbox it would still be cool to 'homebrew' it.

[speachy]

There is nearly no documentation on the ATJ2127 to be found online, and what little exists is in Chinese.

I've seen some of these 2127-based players boot entirely from on-chip flash, others use off-chip flash (sometimes in the form of an embedded SD card) formatted a specific way.  The firmware is executed in place, and consists of a series of overlays.    All audio decoding is done using dedicated hardware.  The CPU core is MIPS-based.

There is some additional info here:

   https://www.rockbox.org/wiki/ActionsATJ
   https://www.rockbox.org/wiki/ATJ213xFirmware