Halk,
as elcreative said, CFW is custom firmware. I don't like to call it "hacked firmware" as goals are quite different from typical hacking. There is no DRM circumvention code and neither any attempt to remove 3G browsing restrictions etc, goal is purely to improve device software.
Your problem in short: I guess you've forgotten to unpack the launcher for boroda's firmware. (test-startup with its content. The one you got from installing boroda's firmware is not the one)
Regarding your problems, not sure if I've described it here, so:
"How installing PRS+ works" and why it is done this way:
On older models, 300, 505 it is very easy to experiment with firmware, because you can always put reader in firmware update mode, so there PRS+ is flashed. With 600 onwards there is no such option. On the other hand, PRS+ does quite a lot of things, and it is not possible to foresee all consequences. Flashing it would mean quite a high risk of bricking for developers and not so high but still substantial risk for the users. That's why for newer readers I use the following approach:
- "Base flash", basically original Sony firmware only slightly modified: updated Fonts, user CSS path for EPUBs, and it includes PRS+ Launcher. This part is actually flashed. It would be very rarely, if at all, updated.
- Frequently updated PRS+ code, which is not flashed, but simply copied to a (hidden to the user) partition by PRS+ installer.
How does PRS+ launcher work:- it checks if reader was connected to USB during startup. If not, it does nothing and stops!
- (only if reader wasn't connected to USB) it checks if there is PRS+ installer, if yes, executes it.
- (only if reader wasn't connected to USB) checks if PRS+ code is available in the mentioned hidden partition, if yes, executes it
What do launchers for boroda's / amutin's firmware do?
They call PRS+ launcher.
Why do we need CFW to do it?
Because standard firmware has no suitable "execute someting on startup" feature.