[syslinux] CONFIG

[Ferenc Wagner]

"H. Peter Anvin" <hpa at zytor.com> writes:

> Ferenc Wagner wrote:
> 
>> This may or may not be related, but some time ago we talked about
>> optionally changing the current directory when a new config file is
>> loaded.  Unfortunately I failed to implement this.  However, recently
>> there was some activity around this part of the code.  What do you
>> think about adding the possibility of something like
>> 
>>   LABEL config
>>     CONFIG /some/dir/newconfig.cfg
>>     APPEND cwd
>> 
>> to the effect of setting the current directory to /some/dir, as if
>> newconfig.cfg was read by the loader initially?  This would help a lot
>> integrating several isolinux-booted systems into one CD or USB stick.
>
> I have been thinking about it a lot, but there is a major complication 
> which I haven't had time to come up with a workaround for.  The 
> fundamental problem is that the configuration file needs to be 
> accessible from the new namespace, but it was looked up in the old 
> namespace.  This would require either keeping the full pathname of the 
> current directory at all times (which pxelinux does, but not any of the 
> other derivatives) and canonicalize the configuration file name, or come 
> up with some kind of "magic shortcut" syntax.

Hmm.  What first occurs to me is that in the above (rather restricted)
scheme the config file is always accessible without any path
specification, the current directory being determined by the path of
the config file itself.  Doesn't that help?  Thus it's enough to keep
the basename after changing the current directory.
-- 
Cheers,
Feri.