This player's firmware is based on a Linux platform called HibyOS.  Rockbox
runs as an application, replacing the stock \emph{Hibyplayer} application.

In order to install Rockbox's bootloader, you will need a copy of the
original player firmware.  This can be downloaded from the manufacturer's
web site.  The following stock firmware versions are currently supported:

\begin{itemize}
 \opt{agptekrocker}{
   \item 20171101
   }
\end{itemize}

After downloading the firmware, you will need to download the corresponding
binary patch file (\fname{.bsdiff}) for the firmware version in question, from
the following location:

\begin{itemize}
 \opt{agptekrocker}{
  \item \download{bootloader/agptek}
  }
\end{itemize}

Using the \emph{bspatch} utility, apply the binary patch to the original bootloader, with an output file \fname{update.upt}.  Place this file into the top-level directory of an SD card.

Insert the SD card into the player, turn it on, and navigate the to the \emph{tools} menu, and select \emph{update firmware}.  The device will restart to perform the update, then restart again, after which it will display the Rockbox bootloader menu.
