Hacked touch rockchip mp4, or: how to de-hack in 30sec using linux fdisk
 

Hi,
I recently purchased a so-called "4GB" mp4 touchscreen (the 2.8" iphone/onda vx858 clone we've all seen)
and I noticed that it was acting strangely (locking up when disconnecting from usb, reading files, etc.)
also, the "Properties" panel in windows was showing ~50% of the disk as being used, so a quick check with nand_tool showed that it only had 1 2gb chip in it... (also of interest is that it can use sdhc chips (~8gb) even though it's an rk2608a)
so if course windows still thinks it has 4gb, which it turns out, is because (at least on mine) the partition table is invalid,
In win2k/xp/others it won't let you repartition it because it's a removable disk, and the actions-based tool mentioned on this forum doesn't work on rockchip.

I plug it into my linux box, and promptly get complaints about invalid sector size, partition table errors, and several other errors.

so i think, hmm, let's re-write the partition table, and it'll be fine...

then I ran the following commands -

(/dev/sda was on mine, yours may be different!!!!)

(as root)

fdisk /dev/sda

then deleted the partition - d <enter> 1 <enter>
create new partition - n <enter> <enter> (you want to just let it use the whole thing)
change partition type - t <enter> b <enter> (type b is win95 fat32)
write your changes - w <enter>
quit - q <enter>

then re-create the filesystem - mkfs -t vfat /dev/sda1

results included no more lockups and faster access...
This worked for me, obviously YMMV.