Syslinux - May 2014 - syslinux (pxelinux.0) debug prints

On May 29, 2014 5:25 AM, "Wissam Shoukair" <wissams at
mellanox.com> wrote:
>
> Hi Gene,
>
> I was wondering how I can set the ?printf? output to be visible on the
screen? (I?m using syslinux-6.03-pre02)

printf () or dprintf ()? You need to watch what functions are available at
the time you want to print.  For example, printf isn't available until
ldlinux.c32 is loaded.

Why not 6.03-pre12?

--Gene

Op 2014-05-29 om 06:27 schreef Gene Cumm:
> On May 29, 2014 5:25 AM, "Wissam Shoukair" <wissams at
mellanox.com> wrote:
> >
> > Hi Gene,
> >
> > I was wondering how I can set the ???printf??? output to be visible on
the
> screen? (I???m using syslinux-6.03-pre02)
>
> printf () or dprintf ()? You need to watch what functions are available at
> the time you want to print.  For example, printf isn't available until
> ldlinux.c32 is loaded.
>
> Why not 6.03-pre12?
>
I have to work with this version???

Apparently that???s why I don???t see the prints. I don???t think
ldlinux.c32 is loaded yet. how I can print messages in the beginning
of pxelinux.0
For example, I need to add print to the following places:
pxe_fs_init() in core/fs/pxe/pxe.c
gpxe_init in core/fs/pxe/bios.c
pxe_call in core/fs/pxe/pxe.c
call16 in core/call16.c

To be more specific, I have a problem with versions later than 5.01.
Until version 5.01 I can boot as usual with no issues.
However, when I use pselinux.0 version 5.02 and up, the following problem
happens:

1.       My PXE driver loads and the links are up

2.       The interface gets an IP address from the DHCP server, and it gets
         the filename to download from the same server (which is pxelinux.0)

3.       The PXE client downloads pxelinux.0 file.

4.       When it starts to load the system crashes and reboots.

I was able to pin down the issue with stalls (sleep() function). I suspect
that the addresses of the PXE API are not correct or corrupted somehow.
When I call this function (core_farcall((size_t)func, &xreg, oreg);
in file core/call16.c), the system crashes???
Do you have any suggestions?


Thanks,
wissam

On 05/29/2014 09:50 AM, Wissam Shoukair wrote:
> 
> I have to work with this version???
> 
That is highly unfortunate, since the version you "have to work with"
has a number of bugs, many of which have already been fixed.

	-hpa

On Thu, May 29, 2014 at 12:50 PM, Wissam Shoukair <wissams at
mellanox.com>
wrote:
> Op 2014-05-29 om 06:27 schreef Gene Cumm:
>> On May 29, 2014 5:25 AM, "Wissam Shoukair" <wissams at
mellanox.com> wrote:
>> >
>> > Hi Gene,
>> >
>> > I was wondering how I can set the ???printf??? output to be
visible on
the
>> screen? (I???m using syslinux-6.03-pre02)
>>
>> printf () or dprintf ()? You need to watch what functions are available
at
>> the time you want to print. For example, printf isn't available
until
>> ldlinux.c32 is loaded.
>>
>> Why not 6.03-pre12?
>>
>
> I have to work with this version???
> Do you have any suggestions?
On Thu, May 29, 2014 at 1:15 PM, H. Peter Anvin <hpa at zytor.com>
wrote:
> On 05/29/2014 09:50 AM, Wissam Shoukair wrote:
>>
>> I have to work with this version???
>>
>
> That is highly unfortunate, since the version you "have to work
with"
> has a number of bugs, many of which have already been fixed.
>
> -hpa
I agree.

The biggest suggestion is to NOT use a pre-release version which has
numerous bugs resolved in later pre-release versions as you are likely to
encounter at least one of them. I believe at least some of these bugs were
carry-overs from 5.0x.

-- 
-Gene