Hi Pax,
Glad you got the build working.
Yes, you can certainly setup your system as standalone with the MSX keyboard/display as your console.
First, you should make sure that the MSX keyboard and display work as a console To do that, start your system normally (using serial connection). Then, from the Boot Loader prompt, enter "I n" where n is the Character Device Unit number of your MSX keyboard/display. You determine the Character Unit number by looking at the device list at boot. In your case, I think it is going to be Character Unit 2. So, you would enter "I 2". After pressing enter, your console should switch to the MSX keyboard/display. You should now be able to use your system from the MSX keyboard/display to boot CP/M, etc.
By the way, there is another (easier) way to switch the console to your MSX keyboard/display. After booting your system, without typing anything at the serial port, press the space key twice on the MSX keyboard/display. The MSX keyboard/display should now activate just like when you used "I n" above. Pressing the space key twice will work even if you have nothing attached to the serial port. Oh, I forgot. For this to work you must ensure that VDAEMU_SERKBD is set to $FF in your config file (RCZ80_std.asm):
VDAEMU_SERKBD .SET $FF ; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
If you want your system to boot directly to the MSX keyboard display at boot, you can set CRTAC T to TRUE in your config file (RCZ80_std.asm):
CRTACT .SET TRUE ; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
An even better way to do this is to add an RC2014 front panel kit. The front panel switches can then be used to control a variety of startup options including selection of serial vs. CRT console.
Thanks,
Wayne