[syslinux] Problem with 90MB Initrd

[Gene Cumm]

On Wed, Sep 23, 2015 at 4:58 PM, Gene Cumm <gene.cumm at gmail.com> wrote:
> On Wed, Sep 23, 2015 at 4:24 PM, Patrick Masotta <masottaus at yahoo.com> wrote:
>>>>>
>>
>>  > BTW if you take a minute and read the first report
>>  > https://communities.vmware.com/message/2536774
>>  > You'll realize that VMWare TFTP "surprisingly" does not present slow TFTP transfers
>>  > when they are driven by MS "bootmgfw.efi"; instead the problem is only shown when
>>  > transfers are driven by syslinux.efi; At the moment, despite probably VMware not handling
>>  > the net driver "polling" correctly, I started to wonder if "we" are really handling the EFI Event
>>  > engine correctly when performing TFTP transfers within syslinux.efi
>>  >
>>
>>  It might be a difference
>>  between using the TFTP and using the UDP
>>  interfaces, or somesuch.
>>
>>      -hpa
>>  <<<
>>
>> Sure "bootmgfw.efi" is doing something better than we do about TFTP transfers.
>> They:
>> 1) do not rely on Service Binding Protocols then old EFI firmware PCs do not complain.
>> 2) I think they do better when handling EFI Events and Timers.
>>
>> The key to see how they do what they do is this bootmgfw.efi function:
>> TftppGetImageRegular
>> but the task is time consuming; efi environment functions are only referenced by an index
>> on a pointer table then knowing what functions they are really calling is not very easy
>> to see.
>
> My current inclination is that there's a bug in Syslinux's TFTP+UDP
> implementation.  If it's in the TFTP implementation, lpxelinux.0
> should also exhibit issues with larger files (which I seem to recall
> but can't be certain at the moment).

lpxelinux.0 seems clear of this issue.  I did a transfer of ~76MB and
didn't see any decay.  I'm thinking either UDP or memory allocation
bug/misuse.

-- 
-Gene