So, I enabled the ONDA players in rbutil but it copies only the RB folder but the boot loader con't be copied.
I red the instructions but I don't understand all the passages and first of all from the link to download the original firmware I get only a .img file and not a .HFX file.
I own the Onda VX777R type, it has no volume down/up switches on the edges, it has only the on/off button, USB slot, microSD slot,mic hole, reset hole/switch and mini jack in.