[syslinux] Getting HTTP path-prefix to work with syslinux.efi

[Gene Cumm]

On Tue, Jun 14, 2016 at 4:44 PM, Alexander Perlis <aperlis at math.lsu.edu> wrote:
>>> Doesn't work. Apparently the Dell UEFI PXE firmware doesn't know HTTP.
>>
>>
>> There's a lot of variation. Do you have a shell option
>> in your boot selections?
>
>
> None of Dell OptiPlex 990 (firmware A19), 9010 (firmware A22), nor 9020
> (firmware A16) seem have a built-in EFI shell option, but in all three cases
> I had success running the external EFI shell from
> github.com/tianocore/edk2/tree/master/EdkShellBinPkg (naming it
> /efi/boot/bootx64.efi on a FAT USB stick).

Examining a 9020 I have access to, I'm guessing that depends on what's
on the HDD.

>> I'm guessing a lack of TCPv4Sb (an alias for the
>> EFI_TCP4_SERVICE_BINDING_PROTOCOL ).
>
>
> You're onto something. All three systems do report TCPv4Sb identically in
> their "guid" output,
>
> TCPv4Sb : 00720665-67EB-4A99-BAF7-D3C33A1C7CC9
>
> yet in the "dh -p Net" output, only the OptiPlex 9020 lists TCPv4Sb. That is
> also the only one of the three systems for which syslinux.efi is indeed able
> to load HTTP URLs.
>
> What does it mean for TCPv4Sb to be listed under "guid" yet not under "dh -p
> Net"? Curiously, on the OptiPlex 990, the "dh -p Net" output is bizarrely
> essentially empty:

It means it understands what alias to assign for the GUID but might
not have a binding for it or placed it elsewhere.  The following would
find the binding if it existed elsewhere.


dh -p TCPv4Sb


> Dell OptiPlex 990 A19 (EFI 2.0 Revision 4.632 American Megatrends):
>
> Shell> dh -p Net
> Handle dump by protocol 'Net'
>
>
>
> Dell OptiPlex 9010 A22 (EFI 2.31 Revision 4.653 American Megatrends):
>
> Shell> dh -p Net
> Handle dump by protocol 'Net'
>
>  326: DevPath (..9,0x0)/MAC(xxxxxxxxxxxx,0x0))Net MNPSb ARPSb DHCPv4Sb
> IPv4Sb IPv4Config UDPv4Sb MTFTPv4Sb HiiConfAccess
>
>  341: DevPath (..HCP,0.0.0.0,0.0.0.0,0.0.0.0))Load Net Pxebc
>
>  349: DevPath (..00:0000:0000:0000:0000:0000))Load Net Pxebc
>
>
>
> Dell OptiPlex 9020 A16 (EFI 2.31 Revision 4.653 American Megatrends):
>
> Shell> dh -p Net
> Handle dump by protocol 'Net'
>
>  335: DevPath (..9,0x0)/MAC(xxxxxxxxxxxx,0x0))Net MNPSb ARPSb DHCPv4Sb
> TCPv4Sb IPv4Sb IPv4Config UDPv4Sb MTFTPv4Sb HiiConfAccess
>
>  344: DevPath (..00:0000:0000:0000:0000:0000))Load Net Pxebc
>
>  359: DevPath (..HCP,0.0.0.0,0.0.0.0,0.0.0.0))Load Net Pxebc

Thanks for the results.  The observed behavior is inline with my
expectations for this output.

-- 
-Gene