[syslinux] SYSLINUX: Neither prompt nor menu?

[Ady]

> Good day,
> 
> I was expecting this to be a FAQ but haven't been able to find an 
> answer... how would I arrange to, normally, not be presented with either 
> prompt or menu when booting, yet be still able to call up prompt/menu 
> when needed?
> 
> If the right answer is "set PROMPT 0, provide a DEFAULT entry and no UI 
> entry" then that doesn't work currently, in the sense that it is then 
> impossible to interrupt the boot even when needed: syslinux pays no 
> attention to ALT or SHIFT in that case (and responds to CTRL by 
> commenting that "this system has only 622K of DOS RAM, whereas this 
> version of syslinux needs 9K to boot!" -- which I will assume to be an 
> unrelated buglet).
> 
> Setting TIMEOUT to 1 with UI={vesa,}menu.c32 gets me a rather annoying 
> flash while booting which I wanted to avoid -- but I only noticed not 
> being able to now intervene anymore until I actually quite needed to. At 
> which point I noticed it definitely enough that I've now regressed to 
> LILO...
> 
> I'm an Arch Linux user and LILO isn't a supported choice, and I would 
> like to return to syslinux. Is ALT/SHIFT not working without a UI 
> statement just a bug? If not, can syslinux do what I want?
> 
> Regards,
> Rene
 
Let's separate the issues.

First, in the 5+ versions of Syslinux, the shift/alt keys are indeed 
not working as expected. This is a bug (among several issues related 
to keyboard functionality).

Now, regarding your goal, you should be able to achieve it by using 
the following directives:
_ MENU CLEAR
_ MENU HIDDEN
_ MENU HIDDENKEY
_ UI [vesa]menu.c32
_ PROMPT
_ DEFAULT
_ TIMEOUT
_ ONTIMEOUT

Some of the above directives might be optional for your goal/needs 
(e.g. using a simple menu or a boot prompt when pressing some key), 
and there are some other directives that could be added so to achieve 
better/different looks.

Regarding the "flash" while booting, you could try adding to your 
APPEND line the following:
 vga=current quiet

Regards,
Ady.