[syslinux] Installers options with additional arguments

[Ady]

Hello,

I have some questions about some of the options for the SYSLINUX 
installers.

Some of the options for the SYSLINUX installers require an additional 
argument. Among others:

"--once="
"--heads="
"--sectors="
"--offset"

I have seen contradictory examples / posts / emails / documentation, so 
I am trying to clarify what is really correct according to the source 
code itself (discarding comments and "usage").

Is the equal sign necessary (for any/all)?
Instead of the equal sign, is a space character accepted for --once?
Instead of the equal sign, is a space character accepted for --heads?
Instead of the equal sign, is a space character accepted for --sectors?


Considering that --heads and --sectors are sometimes documented with 
the equal sign, and --offset expects a numeric value too, is 
"--offset=" (with an equal sign) accepted too?


What kind of numeric value is accepted for "--heads" and for 
"--sectors"? Decimal? Hex?


What kind of numeric value is accepted for "--offset"? Decimal? Other?

In which kind of units the --offset value is interpreted? Amount of 
Sectors? Bytes? KiB?

When using --offset (on an image file), what the offset value should 
be? Is it the start of the volume inside the image file (aka. absolute 
hidden sectors before volume)?


What kind of commands are accepted for --once? Labels only? Any command 
accepted by the Syslinux CLI? Part of them? If not using a label, can 
the command include space characters?


Hopefully the answers can help clarify the documentation (and my 
doubts).

TIA,  
Ady.