Syslinux - Dec 2014 - Using of pxelinux configfiles for both BIOS and UEFI boot

> Hello everyone,
>
> I'm using a windows PXE server and I try to upgrade a existing PXELINUX
menu structure with actually with BIOS/Legacy mode to work in UEFI mode too.
>
> Since I have to use ZENworks tftp on the windows server I have only one
TFTP-root directory not 2 different tftp-root directories like on a standard
windows
> deployment server. ZENworks itself uses for Legacy mode a patched PXELINUX
and for UEFI a patched grub boot manager to get both running.
>
> - Is there a standard approach to use different vesamenu.c32 (and other
architecture depending ) files in the pxelinux.cfg/default file depending on the
boot architecture - especially for BIOS/Legacy and EFI64?
> - Is it e.g. possible to set and use variables depending on the boot
architecture in the default menu  pxelinux.cfg/default to address different
vesamenu.c32 files?
>
> I sniffed network traffic, googled and looked at the SYSLINUX wiki, but
always get stuck with the problem that I can't address two different
vesamenu.c32 (or menu.c32) modules depending on BIOS or UEFI boot.
> Maybe I'm just missing just a little detail.
>
> I'm using SYSLINUX 6.03 for the existing PXE menu structure with a 
large number of PXELINUX configuration files (>170), so building a second
structure in grub syntax isn't a way I would like to follow up further.
>
> Using the tftp from the windows deployment could be an option, but would
provoke other incompatibility of services of the MDT server and the ZENworks
infrastructure services.
>
> Yours sincerely
> Peter Leenders
Hello,

I guess a general use of  constants/variables is still not possible as described
in the SYSLINUX wiki - is this correct?
     ->
http://www.syslinux.org/wiki/index.php/SYSLINUX#Is_There_A_Way_To_Define_Constants_Or_Variables.3F

Are the "system" flags to handle this or is there a version of
vesamenu.c32 (and depending modules) that run with both UEFI and BIOS- I
haven't found something like this?

Is it possible to define search paths for the modules so that it is possible to
use both UEFI and BIOS in one TFTP root structure without depending on a special
dhcp.conf (linux) or in my case using 2 different tftp root structures
(windows)?

For belonging ldlinux module the extensions (*.c32, *.e32 and *.e64) allows to
use UEFI and BIOS parallel. Unfortunately this concept is not working for the
other modules like vesamenu and depending modules. Is there a plan to extent
this concept to the other modules?

Peter Leenders

> > Hello everyone,
> >
> > I'm using a windows PXE server and I try to upgrade a existing
PXELINUX menu structure with actually with BIOS/Legacy mode to work in UEFI mode
too.
> >
> > Since I have to use ZENworks tftp on the windows server I have only
one TFTP-root directory not 2 different tftp-root directories like on a standard
windows
> > deployment server. ZENworks itself uses for Legacy mode a patched
PXELINUX and for UEFI a patched grub boot manager to get both running.
> >
> > - Is there a standard approach to use different vesamenu.c32 (and
other architecture depending ) files in the pxelinux.cfg/default file depending
on the boot architecture - especially for BIOS/Legacy and EFI64?
> > - Is it e.g. possible to set and use variables depending on the boot
architecture in the default menu  pxelinux.cfg/default to address different
vesamenu.c32 files?
> >
> > I sniffed network traffic, googled and looked at the SYSLINUX wiki,
but always get stuck with the problem that I can't address two different
vesamenu.c32 (or menu.c32) modules depending on BIOS or UEFI boot.
> > Maybe I'm just missing just a little detail.
> >
> > I'm using SYSLINUX 6.03 for the existing PXE menu structure with a
large number of PXELINUX configuration files (>170), so building a second
structure in grub syntax isn't a way I would like to follow up further.
> >
> > Using the tftp from the windows deployment could be an option, but
would provoke other incompatibility of services of the MDT server and the
ZENworks infrastructure services.
> >
> > Yours sincerely
> > Peter Leenders
> 
> Hello,
> 
> I guess a general use of  constants/variables is still not possible as
described in the SYSLINUX wiki - is this correct?
>      ->
http://www.syslinux.org/wiki/index.php/SYSLINUX#Is_There_A_Way_To_Define_Constants_Or_Variables.3F
> 
> Are the "system" flags to handle this or is there a version of
vesamenu.c32 (and depending modules) that run with both UEFI and BIOS- I
haven't found something like this?
> 
> Is it possible to define search paths for the modules so that it is
possible to use both UEFI and BIOS in one TFTP root structure without depending
on a special dhcp.conf (linux) or in my case using 2 different tftp root
structures (windows)?
> 
> For belonging ldlinux module the extensions (*.c32, *.e32 and *.e64) allows
to use UEFI and BIOS parallel. Unfortunately this concept is not working for the
other modules like vesamenu and depending modules. Is there a plan to extent
this concept to the other modules?
> 
> Peter Leenders
> 
> 
> 
> 
> 
> _______________________________________________
> Syslinux mailing list
> Submissions to Syslinux at zytor.com
> Unsubscribe or set options at:
> http://www.zytor.com/mailman/listinfo/syslinux
> 
See the PATH directive:
http://www.syslinux.org/wiki/index.php/Config#PATH
and the links from that section.

For some general information:
http://www.syslinux.org/wiki/index.php/Library_modules

For a basic starting point for dhcp config for mixed BIOS/UEFI clients:
http://www.syslinux.org/wiki/index.php/PXELINUX#UEFI

For multiple architectures / firmware variants, see basic clues:
http://www.syslinux.org/wiki/index.php/PXELINUX-Multi-Arch

Note the usage of "::" as tftp root.

You should be aware that mixing versions of Syslinux should be avoided, 
and that part of the directives are not supported in older versions.

Regards,
Ady.

On Dec 8, 2014 5:24 AM, "Leenders, Peter" <Peter.Leenders at
computacenter.com>
wrote:
>
> > Hello everyone,
> >
> > I'm using a windows PXE server and I try to upgrade a existing
PXELINUX
menu structure with actually with BIOS/Legacy mode to work in UEFI mode
too.
> >
> > Since I have to use ZENworks tftp on the windows server I have only
one
TFTP-root directory not 2 different tftp-root directories like on a
standard windows
> > deployment server. ZENworks itself uses for Legacy mode a patched
PXELINUX and for UEFI a patched grub boot manager to get both
running.
> >
> > - Is there a standard approach to use different vesamenu.c32 (and
other
architecture depending ) files in the pxelinux.cfg/default file depending
on the boot architecture - especially for BIOS/Legacy and EFI64?

I'd say there's no standard but there are choices.  Check out this page
I
wrote up.

http://www.syslinux.org/wiki/index.php/PXELINUX-Multi-Arch
> > - Is it e.g. possible to set and use variables depending on the boot
architecture in the default menu  pxelinux.cfg/default to address different
vesamenu.c32 files?

Not quite.  INCLUDE and PATH with a different initial config per
architecture (which I apparently didn't finish).  Ensure each architecture
gets a different initial config file that's two lines:

  PATH bios
  INCLUDE common-config

  PATH efi32
  INCLUDE common-config

  PATH efi64
  INCLUDE common-config
> > I sniffed network traffic, googled and looked at the SYSLINUX wiki,
but
always get stuck with the problem that I can't address two different
vesamenu.c32 (or menu.c32) modules depending on BIOS or UEFI
boot.
> > Maybe I'm just missing just a little detail.
> > I'm using SYSLINUX 6.03 for the existing PXE menu structure with a
large number of PXELINUX configuration files (>170), so building a second
structure in grub syntax isn't a way I would like to follow up
further.
> >
> > Using the tftp from the windows deployment could be an option, but
would provoke other incompatibility of services of the MDT server and the
ZENworks infrastructure services.
> >
> > Yours sincerely
> > Peter Leenders
>
> Hello,
>
> I guess a general use of  constants/variables is still not possible as
described in the SYSLINUX wiki - is this correct?
>      ->
http://www.syslinux.org/wiki/index.php/SYSLINUX#Is_There_A_Way_To_Define_Constants_Or_Variables.3F

At that level, correct.
> Are the "system" flags to handle this or is there a version of
vesamenu.c32 (and depending modules) that run with both UEFI and BIOS- I
haven't found something like this?

No,  each is architecture-specific.  Different PATH statements is the
closest.
> Is it possible to define search paths for the modules so that it is
possible to use both UEFI and BIOS in one TFTP root structure without
depending on a special dhcp.conf (linux) or in my case using 2 different
tftp root structures (windows)?

Yes, pxelinux-options to unique initial configs.  See link.
> For belonging ldlinux module the extensions (*.c32, *.e32 and *.e64)
allows to use UEFI and BIOS parallel. Unfortunately this concept is not
working for the other modules like vesamenu and depending modules. Is there
a plan to extent this concept to the other modules?

I believe that there was debate and the decision was common name extension.

--Gene

>> Hello everyone,
>>
>> I'm using a windows PXE server and I try to upgrade a existing
PXELINUX menu structure with actually with BIOS/Legacy mode to work in UEFI mode
too.
>>
>> Since I have to use ZENworks tftp on the windows server I have only 
>> one TFTP-root directory not 2 different tftp-root directories like on a
standard windows deployment server. ZENworks itself uses for Legacy mode a
patched PXELINUX and for UEFI a patched grub boot manager to get both running.
>>
>> - Is there a standard approach to use different vesamenu.c32 (and other
architecture depending ) files in the pxelinux.cfg/default file depending on the
boot architecture - especially for BIOS/Legacy and EFI64?
>> - Is it e.g. possible to set and use variables depending on the boot
architecture in the default menu  pxelinux.cfg/default to address different
vesamenu.c32 files?
>>
>> I sniffed network traffic, googled and looked at the SYSLINUX wiki, but
always get stuck with the problem that I can't address two different
vesamenu.c32 (or menu.c32) modules depending on BIOS or UEFI boot.
>> Maybe I'm just missing just a little detail.
>>
>> I'm using SYSLINUX 6.03 for the existing PXE menu structure with a 
large number of PXELINUX configuration files (>170), so building a second
structure in grub syntax isn't a way I would like to follow up further.
>>
>> Using the tftp from the windows deployment could be an option, but
would provoke other incompatibility of services of the MDT server and the
ZENworks infrastructure services.
>>
>> Yours sincerely
>> Peter Leenders
>
> Hello,
>
> I guess a general use of  constants/variables is still not possible as
described in the SYSLINUX wiki - is this correct?
>      ->
http://www.syslinux.org/wiki/index.php/SYSLINUX#Is_There_A_Way_To_Define_Constants_Or_Variables.3F
> 
> Are the "system" flags to handle this or is there a version of
vesamenu.c32 (and depending modules) that run with both UEFI and BIOS- I
haven't found something like this?
> 
> Is it possible to define search paths for the modules so that it is
possible to use both UEFI and BIOS in one TFTP root structure without depending
on a special dhcp.conf (linux) or in my case using 2 different tftp root
structures (windows)?
> 
> For belonging ldlinux module the extensions (*.c32, *.e32 and *.e64) allows
to use UEFI and BIOS parallel. Unfortunately this concept is not working for the
other modules like vesamenu and depending modules. Is there a plan to extent
this concept to the other modules?
>
> Peter Leenders
Hello,

here a short feedback:

As a proof of concept I patched in the compiled ldlinux.e64, vesamenu.c32,
libutil.c32 and libcomc32 modules the extension strings c32 to e64 and renamed
than the *.c32 module to *.64.
Since I have no syslinux development environment here, I just patched the
binaries itself.
Additionally I copied the *.c32 Bios modules to the tftp server. 

As result I have no double filenames and BIOS and UEFI compatible versions are
available on the server.

Now it's possible to use UEFI and BIOS modules for vesamenu parallel on a
tftp server with one TFTP root directory. I guess the same procedure will work
for other com32 modules too, but I haven't tested yet.

It may be worth to think about using different extensions in the main syslinux
sourcecode branch to enable parallel UEFI and BIOS booting on a tftp server.

Peter Leenders

> > > Hello everyone,
> > >
> > > I'm using a windows PXE server and I try to upgrade a
existing PXELINUX menu structure with actually with BIOS/Legacy mode to work in
UEFI mode too.
> > >
> > > Since I have to use ZENworks tftp on the windows server I have
only
> > > one TFTP-root directory not 2 different tftp-root directories
like on a standard windows deployment server. ZENworks itself uses for Legacy
mode a patched PXELINUX and for UEFI a patched grub boot manager to get both
running.
> > >
> > > - Is there a standard approach to use different vesamenu.c32 (and
other architecture depending ) files in the pxelinux.cfg/default file depending
on the boot architecture - especially for BIOS/Legacy and EFI64?
> > > - Is it e.g. possible to set and use variables depending on the
boot architecture in the default menu  pxelinux.cfg/default to address different
vesamenu.c32 files?
> > >
> > > I sniffed network traffic, googled and looked at the SYSLINUX
wiki, but always get stuck with the problem that I can't address two
different vesamenu.c32 (or menu.c32) modules depending on BIOS or UEFI boot.
> > > Maybe I'm just missing just a little detail.
> > >
> > > I'm using SYSLINUX 6.03 for the existing PXE menu structure
with a  large number of PXELINUX configuration files (>170), so building a
second structure in grub syntax isn't a way I would like to follow up
further.
> > >
> > > Using the tftp from the windows deployment could be an option,
but would provoke other incompatibility of services of the MDT server and the
ZENworks infrastructure services.
> > >
> > > Yours sincerely
> > > Peter Leenders
> > 
> > Hello,
> > 
> > I guess a general use of  constants/variables is still not possible as
described in the SYSLINUX wiki - is this correct?
> >      -> 
> > http://www.syslinux.org/wiki/index.php/SYSLINUX#Is_There_A_Way_To_Defi
> > ne_Constants_Or_Variables.3F
> > 
> > Are the "system" flags to handle this or is there a version
of vesamenu.c32 (and depending modules) that run with both UEFI and BIOS- I
haven't found something like this?
> > 
> > Is it possible to define search paths for the modules so that it is
possible to use both UEFI and BIOS in one TFTP root structure without depending
on a special dhcp.conf (linux) or in my case using 2 different tftp root
structures (windows)?
> > 
> > For belonging ldlinux module the extensions (*.c32, *.e32 and *.e64)
allows to use UEFI and BIOS parallel. Unfortunately this concept is not working
for the other modules like vesamenu and depending modules. Is there a plan to
extent this concept to the other modules?
> > 
> > Peter Leenders
> > 
> > 
> > 
> See the PATH directive:
>  http://www.syslinux.org/wiki/index.php/Config#PATH
> and the links from that section.
>
> For some general information:
>  http://www.syslinux.org/wiki/index.php/Library_modules
>
> For a basic starting point for dhcp config for mixed BIOS/UEFI clients:
> http://www.syslinux.org/wiki/index.php/PXELINUX#UEFI
>
> For multiple architectures / firmware variants, see basic clues:
>  http://www.syslinux.org/wiki/index.php/PXELINUX-Multi-Arch
>
> Note the usage of "::" as tftp root.
>
> You should be aware that mixing versions of Syslinux should be avoided, and
that part of the directives are not supported in older versions.
>
> Regards,
> Ady.
Hello Ady,

thank you for your answer. The path directive is fine if one want to use modules
in different directories. Unfortunately it does not help if the modules have the
same names - first match wins.
The addressing relative to the working dir would help if ldlinux.* is loaded
from different directories. In my case only the pxelinux.0 file is loaded from
different locations and the loader is loaded from the root. There are more
possible places where pxelinux.0 searches for the loader module, but they do not
differ between UEFI and BIOS as far as I sniffed the traffic. So here also first
match wins.

I worked though the general library modules information, but the only
architecture dependency (in path or ) file name is for the loader module. The
dependency of the modules is well documented in this page, but don't help to
use UEFI and Bios parallel as you have to use different files with same names
depending on the arctitecture/Firmware.

I read also the dhcp config part, but on my configuration with 1 TFTP root
directory and a windows server this is not applicable.
Of course it is possible to use 2 different TFTP root directories on a windows
server and put one menu structure into a subdirectory of the 2 different tftp
roots using mklink.exe.

The part with the DHCP option 209 and 210 options is new to me. It may be worth
to follow this if it is possible to use different config files for different
architectures (UEFI/Bios) an you have not to change to many submenu files. If
one could use variables or constants or path options in here this would help. At
the moment I'm not sure if it is possible to use different config files for
BIOS/UEFI on a windows server with this option.


Peter

Hello Gene,

thank you for your answer

> > - Is there a standard approach to use different vesamenu.c32 (and
other architecture depending ) files in the pxelinux.cfg/default file depending
on the boot architecture - especially for BIOS/Legacy and EFI64?
>  I'd say there's no standard but there are choices.  Check out this
page I wrote up.
> http://www.syslinux.org/wiki/index.php/PXELINUX-Multi-Arch
>> > - Is it e.g. possible to set and use variables depending on the
boot architecture in the default menu  pxelinux.cfg/default to address different
vesamenu.c32 files?
> Not quite.  INCLUDE and PATH with a different initial config per
architecture (which I apparently didn't finish).  Ensure each architecture
gets a different initial config file that's two lines:
>  PATH bios
>  INCLUDE common-config
>  PATH efi32
>  INCLUDE common-config
>  PATH efi64
>  INCLUDE common-config
This look promising, if I could separate the config files for the different boot
architectures Bios and UEFI. I have 2 different boot files in 2 different
locations, but after startup they both  refer to the
tftproot/pxlinux.cfg/default config file. The DHCP Option 209 may solve this if
the ZENworks tftp server support this option with different values depending on
the architecture. Unfortuanelly til now I didn?t found out if there is a support
for this option.

> > For belonging ldlinux module the extensions (*.c32, *.e32 and *.e64)
allows to use UEFI and BIOS parallel. Unfortunately this concept is not working
for the other modules like vesamenu and depending modules. Is there a plan to
extent this concept to the other modules?
>I believe that there was debate and the decision was common name extension.
Meanwhile I found a workaround for my problem by using different extensions
depending on the architecture by patching the binaries. Since using different
com32 module in multi arch environments is problematic not only in my
environment ? I think loud: Can this be an approach to handle this problems in a
simple an clearly laid out way. It would be simple to handle multi-arch com32
files on a simple tftp server without using not always supported dhcp options or
complicated config files? It?s just a renaming of binaries and of the
dependencies in the source code and 1 extension for each boot architecture. E.g.
*.c32 for bios and *.e64 for UEFI.

Maybe the mentioned debate can be reopened since multi boot architecture are
more common today?

Peter