[syslinux] [PATCH 3/3] syslinux: support isolinux configuration files

[Pete Batard]

On 2012.02.14 17:34, H. Peter Anvin wrote:
> I do NOT want to support isolinux.cfg for
> non-ISOLINUX simply because it is now defined explicitly as "the
> filename to use if you only want ISOLINUX to read it" (there are people
> who want the same file respository to work for ISOs and filesystem-based
> USB sticks, but want slightly different behavior, mostly related to
> chainloading.

But what about precedence then?

Let's consider the case where someone created an ISO using both 
syslinux.cfg and isolinux.cfg.

When the file contents are on an ISO and isolinux is used, no problem. 
syslinux.cfg is ignored and isolinux.cfg is used.
When the file contents have been duplicated to disk (USB or HDD), then, 
even with this patch applied, syslinux.cfg will be picked first, which 
is also fine. There is no real risk of isolinux.cfg overrdding syslinux.cfg.

The isolinux config dirs and config file have all been added at the end, 
therefore would be evaluated last, and the only case I have identified 
where the effect would be that an isolinux.cfg would be picked over a 
syslinux.cfg due to this patch is if someone created an ISO that wasn't 
bootable in the first place (isolinux.cfg in /syslinux).

Or can you clarify how adding isolinux.cfg support in syslinux, as the 
patch does, will prevent people who want slightly different behaviour 
between ISO and USB to lose that feature?

Again, the only thing this patch aims at adding is exactly this: "If the 
search for syslinux.cfg has been exhausted and no syslinux config file 
has been found, try to locate and use an isolinux.cfg". In other words, 
its only feature it turning a disk that would fail to boot, using the 
current syslinux, into one that will.

Regards,

/Pete