[syslinux] Some patches from mageia

[Gene Cumm]

On Sat, Dec 12, 2015 at 8:21 AM, Ady via Syslinux <syslinux at zytor.com> wrote:
>
>> On Thu, Dec 10, 2015 at 5:15 PM, Sebastian Herbszt <herbszt at gmx.de> wrote:
>> > Gene Cumm wrote:
>> >> On Tue, Dec 1, 2015 at 3:02 PM, Erwan Velu via Syslinux
>> >> <syslinux at zytor.com> wrote:
>> >> > Hi folks,
>> >> >
>> >> > As per Ady request (thanks for the reminder), I forgot to send the patches
>> >> > I run in Mageia.
>> >> >
>> >> > There is two of them :
>> >> >
>> >> > One is making errors in parsing modules.alias not fatal.
>> >> >
>> >> > The other one is adding an option to chain to avoid reading garbage on the
>> >> > command line.
>> >> > I had some issues with gfxboot and had to implement that. I know it's a
>> >> > workaround, I don't really get if that's useful for others. You can forget
>> >> > it if you consider it as too weird.
>> >>
>> >> This almost sounds like a global APPEND was used.  Current Syslinux
>> >> should ignore the global APPEND for COM32 use but other config parsers
>> >> like (vesa)menu.c32 and gfxboot.c32 might not as they don't call by
>> >> LABEL but execute plain commands.
>> >
>> > How can I reproduce this issue?
>> >
>> > Sebastian
>>
>> http://rpmfind.net/linux/mageia/distrib/cauldron/i586/isolinux/isolinux.cfg
>> and http://rpmfind.net/linux/mageia/distrib/cauldron/x86_64/isolinux/isolinux.cfg
>> ( http://distro.ibiblio.org/mageia/distrib/cauldron/ appears to be
>> another mirror) look clean from anything that should resemble a global
>> APPEND.
>>
>> Using the files from the above directory, I see
>> "automatic=method:cdrom" appended as an extra argument.  Trimming
>> unnecessary files, I can get it to an ISO under 1 MiB (trim hdt.c32,
>> memtest, modules.*, *.ids, *.hlp ).
>>
>> --
>> -Gene
>
> FWIW, kernel.org also has mirror(s) for mageia (including these
> directories / files).
>
> IIRC, the issue is not related to any global APPEND (mageia does not
> use it), but to the interaction between gfxboot.c32 and chain.c32.
>
> To replicate, see "gfxboot.cfg" and "isolinux.cfg" for mageia (in the
> aforementioned directories)
>
> Relevant lines in these 2 cfg files:
> ["gfxboot.cfg"]
> ; main menu items where user can't add boot options
> nobootoptions=harddisk,memtest
> ; main menu items that are not passed an 'install' parameter
> noinstallopt=harddisk,firmware,memtest
> [/"gfxboot.cfg"]
>
> ["isolinux.cfg"]
> ui gfxboot.c32 bootlogo
> label harddisk
>   com32 chain.c32 hd0 exit
> [/"isolinux.cfg"]
>
> As usual, using 3 or more menu entries is recommended so to avoid the
> minor "quirks" when using less than that amount. Please don't forget to
> use unique LABELs without special characters (such as spaces).
>
> Alternatives for potential testing, either with the original Syslinux
> 6.03, or with later development code before the introduction of the
> "exit" hack:
> ["isolinux.cfg"]
> ui gfxboot.c32 bootlogo
> label harddisk
>   com32 chain.c32 hd0
>   # no "exit"
> [/"isolinux.cfg"]
>
> ["isolinux.cfg"]
> ui gfxboot.c32 bootlogo
> label harddisk
>   com32 chain.c32
>   append hd0 exit
>   # using "append"
> [/"isolinux.cfg"]
>
> ["isolinux.cfg"]
> ui gfxboot.c32 bootlogo
> label harddisk
>   com32 chain.c32
>   append hd0
>   # using "append" but no "exit"
> [/"isolinux.cfg"]
>
> ["isolinux.cfg"]
> ui gfxboot.c32 bootlogo
> label harddisk
>   com32 chain.c32
>   # using no parameter at all, thus using the default
> [/"isolinux.cfg"]
>
> Additional alternative testing:
>
> From the gfxboot screen, exit to the "normal" Syslinux boot prompt and:
> _ type in "harddisk" (thus, using the label from isolinux.cfg); and/or,
> _ type in the command, "chain.c32 hd0".
>
> The last 2 alternative tests should allow to get the expected result
> without the interference of gfxboot. This is usually not what is wanted
> for final users to use; this is just a workaround, and a method to test
> the interaction with gfxboot.

I'm going to guess it's related to bootlogo since the string is found
at offset 0x12387.

-- 
-Gene