On 20.04.2018 10:40, Thomas Huth wrote:
> On 20.04.2018 09:54, Viktor VM Mihajlovski wrote:
>> On 20.04.2018 09:36, Thomas Huth wrote:
>>> On 20.04.2018 08:53, Viktor VM Mihajlovski wrote:
>>>> On 19.04.2018 18:55, Thomas Huth wrote:
>> [...]
>>>> Well, if we don't add another identifier, and I feel reluctant about it
>>>> as well for the reasons you wrote, we may stick with 0x1f and consider
>>>> the additional capabilities as being optional (for special needs only).
>>>
>>> I tend to stay with 0x1f, since booting binaries is still the "primary"
>>> interface (the first check for the "default" or "# " magic keywords is
>>> not 100% reliable, since the config file could also start with another
>>> command, and the probing of pxelinux.cfg/* files is only tried afterwards).
>>>
>> Good. It would be important though to define and document the best way
>> to configure a pxelinux setup: empty bootfile name, bootfile empty (or
>> not existent) or a special file format for the bootfile content (like
>> 'PXE0' in EBCDIC). The former two carry the danger of accidentally
>> enabling the pxe-style boot process.
>
> I don't like the idea of providing a bootfile with a magic content ...
> if you have to provide a bootfile, you could also go with specifying
> pxelinux.cfg/default (or whatever) directly, you just have to make sure
> that the file starts with the right magic ("default" or "# ").
>
> But I agree that starting to guess the non-MAC-based filenames in case
> the boot file name is empty carries some danger, indeed. If we load
> pxelinux.cfg/default on s390x, who guarantees that this was not the
> default file for x86 instead? Maybe we should rather use "pzelinux.cfg"
> as directory ;-) ?
Yep. Sounds as if a null bootfile name should not be allowed at all and
should be rejected by the netboot bios.
>
> Or maybe it would rather make sense to force the users to specify the
> path to the pxelinux config files instead, ending with a slash, so they
> have to put "pxelinux.cfg/" or whatever location into the bootfile
> parameter?
Since the bootfile has to be architecture specific anyway, it would a
good idea to put it into a separate directory, e.g. "/tftpboot/s390".
If the bootfile reported would be "/s390/" or a (nonexisting)
"/s390/pxelinux.0", the new pxe loader could start its
pxelinux.cfg/whatever probing from there. "/" or
"/some-not-existing-file" would be a special case thereof.
>
> Thomas
>
--
Regards,
Viktor Mihajlovski
