set root='(hd0,2)'
tells grub2 that the boot folder can be found on second partition. Normally people make the first partition boot if its to be separate from all others
set root does not point to / unless boot is a sub-folder to /......is that clearer?
I also drop the ' surrounding ()
Now if you have a (separate to / ) boot partition, then you must drop boot out of the menuentry so it looks like
linux /TC64/vmlinuz64
initrd /TC64/corepure64.gz
If you can connect a bootable usb to this tablet maybe show us the output to
blkid | grep sd
2) Personally I don't like UUID so while you have the live usb booted up lets create some labels,
pretending you have TC on an usb stick as I don't know what partitions are on it,
create a new unique file under home/tc
touch /home/tc/zkx
tc@box:~$ sudo find / -name zkx
/home/tc/zkx
/mnt/sdb1/home/tc/zkx
Your result will differ, the important thing is, you now know /mnt/sdb1 in my example is the usb stick so when you look at blkid, you can unmount all
/dev/sdx where sdx is not sdb, most likely sda
sudo umount /mnt/sda1
sudo umount /mnt/sda2 etc
Now if you have loaded (downloaded) e2fsprogs.tcz it has a command called e2label, so we use it like this
sudo e2label /dev/sda1 tabpart1
sudo e2label /dev/sda2 tabpart2
now back on your grub2 kernel line, if you want full persistence your line reads
linux /TC64/vmlinuz64 home=LABEL=tabpart2 opt=LABEL=tabpart2 tce=LABEL=tabpart2 waitusb=5:LABEL=tabpart2
Of course I don't know where your / partition is, and whether you want full persistence I am just jumping ahead to show you a better grub2 kernel line