File Renaming Won't Stay In Uppercase!

[fdlchris]

This one is driving me mad!
 
I am attempting to run the OutcaST ATARI ST emulator on my CAANOO, which requires an operating system image file to be named TOS.ROM.  Any deviation from that filename (including cases), and the emulator will not recognise it.
 
I renamed my image file to TOS.ROM, but when I copied it to my CAANOO's SD card (via Samba), the file is automatically renamed to tos.rom.  Any attempts to rename it back to uppercase characters fails, either using Windows Exporer or the CAANOO app, Bennu File Manager.
 
1) Renamed tos.rom to tosABC.rom.  The file is now called tosABC.rom.
2) Renamed tosABC.rom to tosABC.ROM.  The file is now called tosABC.ROM.
3) Renamed tosABC.ROM to TOS.ROM.  The file is now called tos.rom.
 
After renaming the file TOSa.ROM, I tried to remove the last lowercase character, but as soon as I did, it renamed to tos.rom.
 
Someone please help as I'm tearing my hair out on this one!

 

[alxm]

A quick online search for "vfat uppercase file names" reveals that all-uppercase file names can be a problem. I'm not sure if Caanoo can use ext2-formatted cards out of the box, because that would be a solution.