Syslinux - Jul 2014 - Avoid returning to menu if boot error happened

Hi

On Thu, Jul 10, 2014 at 11:04 PM, Ady <ady-sf at hotmail.com>
wrote:
>
>> Hi
>>
>> I have a weird early boot bug that most likely happens because of
>> interaction between syslinux (6.03pre18), btrfs and initram generated
>> by Linux Arch installer.
>>
>> For some reason boot fails. Syslinux prints some information and
>> returns back to the menu. Unfortunately it clears all the messages
>> from screen. I really want to know what boot process prints there.
>>
>> Looking at  com32/elflink/ldlinux/execute.c (I believe it is where the
>> error handled) I see the comment: /* If this returns, something went
>> bad; return to menu */
>>
>> Would it be better avoid returning to menu in case of an error? I
>> think syslinux should print message "Press any key to return back
to
>> menu". This will preserve the error messages needed during
debugging.
>> What do you think?
>
> You don't _have_ to use a menu to boot, and the default behavior is
> (or should be) not to clear the screen, so probably you can edit your
> syslinux.cfg so to obtain (and be able to read) the error message
> (that is, if indeed the error message is generated by Syslinux).
>
> For instance:
>  _ avoid the UI directive,
>  _ avoid ONTIMEOUT,
>  _ avoid ONERROR,
>  _ avoid MENU CLEAR
>  _ use a higher TIMEOUT,
>  _ use PROMPT 1,
>  _ use DEFAULT <problematic_label>.
>
> These are just basic changes that _might_ help. In some cases, some
> of the above should not be applied, and sometimes other changes are
> needed.
Thanks, it works! For some reason I thought UI option is required and
the text menu is the default one. After I removed the UI I am able to
see the boot error message.

Though I still think that it makes more sense to do pause on a boot error.
> The main point is that a basic syslinux.cfg (or equivalent) should
> help you see the error messages.
>
> If you need more details, please post your Syslinux configuration
> file.
I was using config file template from my distro
https://projects.archlinux.org/svntogit/packages.git/tree/trunk/syslinux.cfg?h=packages/syslinux

> After I removed the UI I am able to see the boot error message.
 
If the error is related to Syslinux, could you please post it here? 
Is it still happening?

BTW, since the Syslinux package in ArchLinux is currently built with 
less debugging options than the official upstream binaries, perhaps 
you might want to consider testing the latter, so to see whether the 
behavior and the (error) messages are the same.

Regards,
Ady.

Hi

On Fri, Jul 11, 2014 at 12:56 PM, Ady <ady-sf at hotmail.com>
wrote:
>
>> After I removed the UI I am able to see the boot error message.
>
> If the error is related to Syslinux, could you please post it here?
> Is it still happening?
Yes, it is still happening. It is related to btrfs - syslinux has a
bug and cannot boot my vmlinuz file. I am trying to find a simple
repro case for this problem, but still no luck. I'll post the error
later today.
> BTW, since the Syslinux package in ArchLinux is currently built with
> less debugging options than the official upstream binaries, perhaps
> you might want to consider testing the latter, so to see whether the
> behavior and the (error) messages are the same.
I am the co-maintainer of syslinux in Arch and I am the one who
disabled it to workaround previous 64K btrfs limit. I've compiled a
debug version of Arch binaries and I use it right now.