Syslinux - Jun 2011 - com32 compatibility between syslinux 3-4

Hi Everyone,
                This question might be a long shot, but is it possible to mix
and match com32 programs written against Syslinux 3 with com32 programs written
against Syslinux 4 without recompiling.   We are trying to have our com32
programs run with different versions of Syslinux without modification. 
Appreciate any advice,

thanks in advance.

On Thu, Jun 9, 2011 at 21:45, Ayvaz, James <James.Ayvaz at hp.com>
wrote:
> Hi Everyone,
> ? ? ? ? ? ? ? ?This question might be a long shot, but is it possible to
mix and match com32 programs written against Syslinux 3 with com32 programs
written against Syslinux 4 without recompiling. ? We are trying to have our
com32 programs run with different versions of Syslinux without modification.
?Appreciate any advice,
>
> thanks in advance.
I believe the answer is pretty much no.  As things currently stand,
there's definitely no way to take a COM32 binary module compiled for
3.86 and use it in 4.04.

http://syslinux.zytor.com/wiki/index.php/Common_Problems#Modules

-- 
-Gene

On 06/09/2011 06:45 PM, Ayvaz, James wrote:
> Hi Everyone,
>                 This question might be a long shot, but is it possible to
mix and match com32 programs written against Syslinux 3 with com32 programs
written against Syslinux 4 without recompiling.   We are trying to have our
com32 programs run with different versions of Syslinux without modification. 
Appreciate any advice,
> 
It is possible, but the standard library doesn't support it: it would
have to be a COM32R image -- and therefore relocatable -- which looks
for the presence of the protected mode APIs and only uses them if
available, otherwise falls back to the Syslinux 3 int calls.

	-hpa

On 06/09/2011 06:45 PM, Ayvaz, James wrote:
> Hi Everyone,
>                 This question might be a long shot, but is it possible to
mix and match com32 programs written against Syslinux 3 with com32 programs
written against Syslinux 4 without recompiling.   We are trying to have our
com32 programs run with different versions of Syslinux without modification. 
Appreciate any advice,
> 
> thanks in advance.
Thinking about this some more, the sanest way to do this is probably to
use the Syslinux 4 startup, and then walk the pm_cs structure and
replace any fields not present (or if pm_cs itself is not present) with
stubs that call the legacy routines.

I have to warn you that the stability of this interface is not my
highest priority right now.  We may wish to discuss your specific use
cases off-list.

	-hpa