Here is the readme of the latest nightly build (c1a3784.rar):
Code:
OLD 3DS
Move firm directory (run tools/cdn_firm.py to download it) to release/rxTools, then copy the contents of the release/rxTools folder to the root of your SD card.
NEW 3DS
Download 9.5 **encrypted** NATIVE_FIRM (0004013820000002.bin, for cakes) from the web and move it to release/rxTools/firm, then copy the contents of the release/rxTools folder to the root of your SD card.
Nothing about cetk files in this readme. I have an O3DS on FW4.5E, maybe this does not apply to other FW versions and maybe does not apply to N3DS. Anyway with no cek at launch there will be an error message about failed installation, but that won't prevent using rxtools. If you want to speed up launch and no error, just dl the cetk files and rename to *_cetk.bin for example 0004013800000002_cetk.bin, 0004013800000102_cetk.bin and 0004013800000202_cek.bin and put them in the firm dir).
In the previous versions of the readme indeed there were reference to the cetk files BUT only for the NEW 3DS instructions and it was said only to download ONE cetk file, the 3 of them were required on the O3DS.