[syslinux] Module Versioning... and other things

[BALATON Zoltan]

On Tue, 8 Mar 2016, Pete Batard via Syslinux wrote:
> On 2016.03.08 03:10, BALATON Zoltan via Syslinux wrote:
>> The difference is that the
>> headache in this case is for those tech savvy people creating the hybrid
>> iso who should be able to figure it out so the non-tech savvy end users
>> should not have a problem with it as long as used as intended.
>
> You're trying to reframe the context in a direction that was never there. My 
> context was always the one of tech savvy developer trying to create a 
> bootable USB from an ISO (be it in a process that automates this creation or 
> something else, with the goal of making the result easy to use for non 
> teach-savvy users). So I don't think you can go around saying "Ah, but 
> ISOHybrid is for this context and the ldlinux.sys replacement is for that 
> context", when, in essence, those contexts are the same.

I really don't think these are the same context. For isohybrid tech-savvy 
users are creating a bootable iso (from scratch or converting an exiting 
non-hybrid iso) with all of their brain power available to solve problems 
as they encounter it and (hopefully) understanding what they are doing 
with non-tech savvy end users having nothing to do.

While for iso to usb conversion with Rufus non-tech savvy users rely on 
the expertise put in that software to do this conversion for them 
automatically. So Rufus should be as intelligent as a tech-savvy human to 
do this by itself in the general case. This seems to be a bit more 
difficult to me.

I don't think hybrid isos are a better solution just easier to program 
than an automatic conversion because the problems to solve by software is 
not the same.

>> (But then trying to use a
>> substitute part from a release for this customised version would likely
>> break too.)
>
> How so? I would argue that, on the contrary, it's very unlikely that people 
> will modify the Syslinux core files, as opposed to tweaking a module that 
> does something close to what they, but not quite. My experience so far has 
> been that replacing 'ldlinux.sys' by the closest official Syslinux version 
> always works and I haven't seen a single case, so far, where it didn't.

You were lucky. There's nothing that would guarantee this in my 
understanding.

> In other words, as surprising as it may seem, it is my understanding that 
> most Linux distro maintainers are very conscious that what they put on an ISO 
> may end up on a FAT filesystem, and will therefore try to ensure that it will 
> work there. At least I know the Debian people are (and will fix issues 
> related to copying to FAT32 when they arise [1])

In this case the maintainers could just include the needed ldlinux.sys on 
the iso as well so it can be easily converted. This is the same as 
including it in isolinux.bin. Although it's probably easier to do this 
once in syslinux then have all the packagers pick it up with the next 
release than having all of them make a change independently. I'm not 
against this change and I don't have a word on what's included in syslinux 
so you don't have to convince me.

Although as you said, with new machines having UEFI and missing CD/DVD 
drives this problem could resolve itself by USB boot images replacing 
ISOs as the preferred boot media in the near future. (Or even boot over 
http can become the most used way.)

Regards,
BALATON Zoltan