[syslinux] ALLOWOPTIONS directive

[Geert Stappers]

My summary:
   reviewing ALLOWOPTIONS found  reasons
   for further reviewing 'ALLOWOPTIONS'

Op 2014-07-12 om 04:35 schreef Ady:
> 
> > I have some questions about "ALLOWOPTIONS 0".
> > 
> > [quote]
> > ALLOWOPTIONS flag_val 
> > If flag_val is 0, the user is not allowed to specify any arguments on 
> > the kernel command line. The only options recognized are those 
> > specified in an APPEND) statement. The default is 1.
> > [/quote]
> > 
> > My understanding of the behavior of "ALLOWOPTIONS 0" is that unless I 
> > type-in a command that is exactly the same as the result of executing 
> > a label, then the command is "not accepted" ("not allowed").
> > 
> >  1_ Is my understanding correct?

Yes, at least that is how I understand the provided [quote/]


> >  2_ Are there any cases in which the resulting behavior is different 
> > from using the IMPLICIT directive (with respective labels)?
> > 
> > While using 'ALLOWOPTIONS 0'...
> >   3_ Should typing-in a 'label' (instead of the whole equivalent 
> > command) be accepted too?

Yes, chosing a 'label' should be possible.
Changing the behaviour of the label not.


> >   4_ If I type-in a 'label' in the CLI, should additional options be 
> > allowed?

See 3_

> >   5_ If I press Tab in [vesa]menu.c32 and delete part of the command, 
> > is the resulting command allowed?

I think the question is 'should it be allowed?'


> >   6_ How exactly is a command "not accepted"? What happens then? Is 
> > the entire command rejected? Or is the typed-in kernel executed 
> > without options? Or is the DEFAULT command executed (without 
> > options)? Or is the ONERROR command executed (without options)? Or is 
> > the first label found with "similar" options executed? Or...?

I don't know.


> > The reason I am asking these questions is because I am testing 
> > "ALLOWOPTIONS 0" and I am slightly confused by the result. Knowing 
> > what I am supposed to expect would help me test the directive 
> > accordingly.

I think Ady found some good reasons to review 'ALLOWOPTIONS' further.


> > TIA,
> > Ady.
> 
> Anyone? Please?

Sorry for not sending an acknowledge message like this more earlier.


Groeten
Geert Stappers
-- 
Leven en laten leven