[syslinux] pxelinux.0 size limits?

[Gene Cumm]

On Sun, Oct 1, 2017 at 4:27 AM, Bruce Ferrell via Syslinux
<syslinux at zytor.com> wrote:
> On 10/01/2017 12:04 AM, Geert Stappers via Syslinux wrote:
>>
>> On Sat, Sep 30, 2017 at 08:53:09PM -0400, Gene Cumm wrote:
>>>
>>> On Sep 30, 2017 8:47 PM, Bruce Ferrell wrote:
>>>>
>>>>
>>>> I've recently seen something to the effect that the pxelinux.0 boot
>>>> loader
>>>> has some limit of 45MB.  Is this correct or some misunderstanding?
>>>
>>>
>>> No, I've loaded 90MB files.  The catch is often TFTP block number
>>> rollover.
>>
>>
>> My first thought was: Which TFTP servers are used?
>> ( What is the name, version and platform of TFTP server where the 45MB
>> limit is encounter? )
>> ( What is the name, version and plafform of TFTP server that is known to
>> server 90 MB files? )
>>
>> On second thought: Use TFTP to download iPXE, continue over HTTP.
>>
>> More about iPXE at http://ipxe.org/
>>
>>
>> Groeten
>> Geert Stappers
>>
>
> I actually ran across the reference while doing research on doing a pxe
> based install of pfSense (FreeBSD based).
>
> I'd run into the tftp issue before on OpenSUSE and solved that with a switch
> of tftp server.
>
> Actually, on Scientific Linux they only give one choice;  the right one!
> Thank you H. Peter Anvin!
>
> I will look into iPXE for the issues the FreeBSD folk fight with.

On the BIOS side, lpxelinux.0 offers HTTP.

As to your "45MB limit", I'd begin to suspect either a small TFTP
block size with no TFTP block number rollover or an older version of
Syslinux, something 4.0x, using a menu with the "quiet" option and
hitting an issue that's obscured while attempting to load the file,
like to a certain spot of memory that fills up.

-- 
-Gene