Make an upgrade microsd card on linux host: how?

vga84

There's a wiki page that describes how to upgrade the board firmware using an upgrade MicroSD card. A procedure that is described involves an SD_Firmware_Tool.exe binary, it's obviously for Windows. Is there a Linux way to make an SD card that will upgrade the firmware?

* Maybe devs a Linux script that allows to do this. If yes can you share this?
* Maybe I can create an update image on Windows just once, save the file, identify where the actual firmware image is and just replace this part of the file to make a new upgrade SD image

The MicroSD update method is more appealing since the button is not very easy to access, but I don't really want to use Windows for this. Maybe once to create a sample image