Syslinux - Nov 2014 - [RFC] make extlinux work without mount the filesystem

On 11/21/2014 02:33 PM, H. Peter Anvin wrote:
> On 11/20/2014 10:21 PM, Robert Yang wrote:
>>
>> which can copy files into test.img without mount it, for example:
>> $ mke2fs -t ext3 -d <rootfs_dir> -F test.img
>>
>> I'd like to make extlinux can work without mount the filesystem
(use
>> libext2fs), is it possible for extlinux, please ? And is such a patch
>> acceptable, please ? (Add a "-d/--device <device>"
option, and the
>> option is optional).
>>
>
> I would definitely accept such a patch.  It probably makes more sense in
the
> "syslinux" installer rather than "extlinux", since the
former already operates
> on an unmounted filesystem.
Great, thanks for the reply, I will do more investigations on syslinux/extlinux,
and ask for help or send a draft design later.

// Robert
>
> I would also love to unify the FAT implementation.
>
>      -hpa
>
>
>
>

> 
> 
> On 11/21/2014 02:33 PM, H. Peter Anvin wrote:
> > On 11/20/2014 10:21 PM, Robert Yang wrote:
> >>
> >> which can copy files into test.img without mount it, for example:
> >> $ mke2fs -t ext3 -d <rootfs_dir> -F test.img
> >>
> >> I'd like to make extlinux can work without mount the
filesystem (use
> >> libext2fs), is it possible for extlinux, please ? And is such a
patch
> >> acceptable, please ? (Add a "-d/--device <device>"
option, and the
> >> option is optional).
> >>
> >
> > I would definitely accept such a patch.  It probably makes more sense
in the
> > "syslinux" installer rather than "extlinux", since
the former already operates
> > on an unmounted filesystem.
> 
> Great, thanks for the reply, I will do more investigations on
syslinux/extlinux,
> and ask for help or send a draft design later.
> 
> // Robert
> 
> >
> > I would also love to unify the FAT implementation.
> >
> >      -hpa
> >
> >
> >
> >
> _______________________________________________
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> Submissions to Syslinux at zytor.com
> Unsubscribe or set options at:
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> 
Let's not forget that:

_ The 'extlinux' command already accepts a "--device
<dev>" parameter.

_ There are several "syslinux installers" (for BIOS) and there should 
be a certain degree of convergence / consistency between them, 
specially regarding the command line arguments (aka. "usage"). This 
convergence should include the Windows-based and DOS-based installers 
as much as possible. Conflicting arguments between the different 
SYSLINUX installers, or breaking backwards compatibility (in terms of 
users' usage, or even regarding procedures and documentation) should be 
minimized as much as possible.

_ Under Linux, we have the (./bios/linux/) 'syslinux-nomtools' 
installer, the (./bios/mtools/) 'syslinux' installer, and the 
(./bios/extlinux/) 'extlinux' installer. They have different 
requirements, different dependencies, and different capabilities, so 
one installer might be more adequate for a certain situation / use-case 
than others.

_ The Windows-based and DOS-based SYSLINUX installers currently do not 
support all the options / capabilities of the Linux-based installers 
(mostly because no one invested time on fully implementing them), but 
they also include capabilities that are not included in the Linux-based 
installers.

_ Whichever additional / proposed / new arguments to be added to any 
one of the SYSLINUX installers, they shall not conflict with arguments 
already included in anyone of the installers (e.g. "-a",
"-m"...).

_ Let's be careful not to allow a "too-easy" execution of code
that
could be potentially harmful. The SYSLINUX installers are frequently 
used by common users with no knowledge nor understanding. If a SYSLINUX 
installer could potentially be used "too-freely" and without special 
requirements / permissions / care, then relevant warnings (and perhaps 
even more than that) should be available to the user before a 
potentially harmful action is actually applied.

Regards,
Ady.

On 11/21/2014 03:17 PM, Ady wrote:
>
>>
>>
>> On 11/21/2014 02:33 PM, H. Peter Anvin wrote:
>>> On 11/20/2014 10:21 PM, Robert Yang wrote:
>>>>
>>>> which can copy files into test.img without mount it, for
example:
>>>> $ mke2fs -t ext3 -d <rootfs_dir> -F test.img
>>>>
>>>> I'd like to make extlinux can work without mount the
filesystem (use
>>>> libext2fs), is it possible for extlinux, please ? And is such a
patch
>>>> acceptable, please ? (Add a "-d/--device
<device>" option, and the
>>>> option is optional).
>>>>
>>>
>>> I would definitely accept such a patch.  It probably makes more
sense in the
>>> "syslinux" installer rather than "extlinux",
since the former already operates
>>> on an unmounted filesystem.
>>
>> Great, thanks for the reply, I will do more investigations on
syslinux/extlinux,
>> and ask for help or send a draft design later.
>>
>> // Robert
>>
>>>
>>> I would also love to unify the FAT implementation.
>>>
>>>       -hpa
>>>
>>>
>>>
>>>
>> _______________________________________________
>> Syslinux mailing list
>> Submissions to Syslinux at zytor.com
>> Unsubscribe or set options at:
>> http://www.zytor.com/mailman/listinfo/syslinux
>>
>
> Let's not forget that:
>
> _ The 'extlinux' command already accepts a "--device
<dev>" parameter.
Ah, yes, what I had tried is the extlinux on Ubuntu 14.04.1, which is
4.05 and didn't have --device, but the git repo has, I will use another
option name.
>
> _ There are several "syslinux installers" (for BIOS) and there
should
> be a certain degree of convergence / consistency between them,
> specially regarding the command line arguments (aka. "usage").
This
> convergence should include the Windows-based and DOS-based installers
> as much as possible. Conflicting arguments between the different
> SYSLINUX installers, or breaking backwards compatibility (in terms of
> users' usage, or even regarding procedures and documentation) should be
> minimized as much as possible.
>
> _ Under Linux, we have the (./bios/linux/) 'syslinux-nomtools'
> installer, the (./bios/mtools/) 'syslinux' installer, and the
> (./bios/extlinux/) 'extlinux' installer. They have different
> requirements, different dependencies, and different capabilities, so
> one installer might be more adequate for a certain situation / use-case
> than others.
>
> _ The Windows-based and DOS-based SYSLINUX installers currently do not
> support all the options / capabilities of the Linux-based installers
> (mostly because no one invested time on fully implementing them), but
> they also include capabilities that are not included in the Linux-based
> installers.
>
> _ Whichever additional / proposed / new arguments to be added to any
> one of the SYSLINUX installers, they shall not conflict with arguments
> already included in anyone of the installers (e.g. "-a",
"-m"...).
>
> _ Let's be careful not to allow a "too-easy" execution of
code that
> could be potentially harmful. The SYSLINUX installers are frequently
> used by common users with no knowledge nor understanding. If a SYSLINUX
> installer could potentially be used "too-freely" and without
special
> requirements / permissions / care, then relevant warnings (and perhaps
> even more than that) should be available to the user before a
> potentially harmful action is actually applied.
>
Thanks, I need more investigations to understand these.

// Robert
> Regards,
> Ady.
> _______________________________________________
> Syslinux mailing list
> Submissions to Syslinux at zytor.com
> Unsubscribe or set options at:
> http://www.zytor.com/mailman/listinfo/syslinux
>
>