[syslinux] EFI: HP + syslinux = crash

[Oscar Roozen]

On 05-08-15 04:17, Ady via Syslinux wrote:
>> Now... why is vesamenu.c32 crashing like it does now? Why is the version
>> I tried without Gene's latest patches crashing before even beginning to
>> load the first stage: ldlinux.e64?
> I think you were "hinted" about this before.

About what? Did I miss something obvious?

I now know why it did not load ldlinux.e64, but I still don't know why 
it crashes. The code seems well written with error checking everywhere, 
so I would expect an error message, or even a silent fail causing the 
boot process to try the DVD player next, or whatever. Not a crash.


> Unfortunately, different
> people define "boot" in different ways.

In this case I define 'boot' as 'reach a stage where syslinux 
successfully loads and runs a linux-kernel'. Up until now I think I 
described reasonably well how far it got into this process.


> The not-so-good "news" is that, considering that vesamenu.c32 has
> several problems (under UEFI), the reasons for your latest crashes
> would need more specific (detailed) investigations and reports (as
> opposed to "failed to boot").

What more can I do?  I dived deep into the C code of a product that I 
don't have intimate knowledge of and spent more time on google than a 
teenager on facebook, but this is all I can provide. Please help me out 
here, as time is running out. I don't own the hardware and will probably 
loose access to it soon.

Unfortunately the debugging process is barely documented at all. The 
wiki page doesn't really help in this case and I had to read the source 
to find out how to enable more verbose output. And then there is this 
problem of stdout not being visible on this EFI system, so I first had 
to debug the debugging system... ;(

Just describing my experience here. I'm new to the syslinux source and 
am having a hard time trying to understand how everything sings along.


> Things that come to mind: the space-like character issues (whether
> SYSAPPEND is being used or not),

Nope.


>additional building interactions (gcc,> gnu-efi...)

I build using 'make spotless; make efi64', initially without any changes 
to the code or makefiles. The build system is Centos 7.1.1503 at the 
moment, with gcc version 4.8.3 20140911 (Red Hat 4.8.3-9). However, 
binaries built by Gene crashed in the same way.


>, the output console (length of the command, keyboard
> issues...), screen resolution supported by your / the UEFI firmware,
> and more.

This all only got relevant yesterday, when I found out that replacing 
vesamenu.c32 with menu.c32 solved the crashes in this case. Are there 
any specific outputs you want to see? Just telling me you need more 
doesn't really help... I don't want to spam the list with everything and 
more I can capture, but if I leave out too much, by all means, please 
ask for it.