be careful here
this is a teclast t29 using a rockchip, the original T29 used a telechip and wolfson audio so the original T29 firmware form teclast will not work
teclast themselves are releasing this player using the rockchip so check their web site before doing anything
i think they call it the TL-C220
this site has some for sale
http://superdaps.ecrater.com/product.php?pid=1646124
LINK to Teclast C220 product page
Teclast C220 (rockchip version of T29)
Firmware for the C220 link to Teclast page
Teclast C220 firmware
Now you still need to be careful with any upgrade, having a known firmware that works for your player is essential.
There is no guarantee that the Teclast firmware will work so your backup/original firmware will at leat allow you to recover to a usable state