[syslinux] UEFI syslinux PXE boot issues

[AL13N]

JZB via Syslinux schreef op 2023-08-17 12:23:
> On 8/17/23 03:55, AL13N via Syslinux wrote:
>> Steve Rikli schreef op 2023-08-16 16:31:
>>> On Wed, Aug 16, 2023 at 02:05:33PM +0200, AL13N via Syslinux wrote:
>>>> Joakim Tjernlund schreef op 2023-08-16 13:15:
>>>> > On Thu, 1970-01-01 at 00:00 +0000, AL13N via Syslinux wrote:
>>>> > >
>>>> > > I'm used to non-UEFI PXE boot, and I use it for my network installer
>>>> > > since forever ago.
>>>> > >
>>>> > > Looking up how to UEFI PXE boot, I use the syslinux.efi file and
>>>> > > allthough it was loaded and stuff, nothing happend after it, I had at
>>>> > > least expected the ldlinux64 to be requested from the TFTP server, but
>>>> > > nothing.
>>>> > >
>>>> > > After searching, I noticed someone asking to test the new pre-release,
>>>> > > and so I downloaded the 6.04 version. I replaced the syslinux.efi file
>>>> > > only, and I got a lot more success. I symlinked the pxelinux.cfg dir
>>>> > > and images so it could find the files it needed.
>>>> > >
>>>> > > Then I got the prompt, I typed "install" to trigger that menu item and
>>>> > > it transferred the vmlinuz file (14sec for 11MB). Then the initrd
>>>> > > (47MB), which takes a long time, but does not ever show the "ok", even
>>>> > > after the transfer was complete (as far as I could tell from the TFTP
>>>> > > server), which takes more than a minute. after some seconds of nothing
>>>> > > happening, it just reboots...
>>>> > >
>>>> > > Can anyone help met out here?
>>>> >
>>>> > If I recall correctly, UEFI is somewhat broken. Try iPXE instead.
>>>> 
>>>> I tried to use the iPXE /usr/share/ipxe/ipxe-x86_64.efi, but it had 
>>>> some
>>>> issues with the network card, iirc, I think I saw the network 
>>>> interface
>>>> down, though it likely uses a wrong driver?
>>>> 
>>>> Still, the newer 6.04 one did work, except for loading the large 
>>>> initrd file
>>>> (which took more than 1 minute, which may be the reason it times 
>>>> out?),
>>>> which is probably not UEFI related?
>>> 
>>> Suggest you try downloading large initrd files with http rather than 
>>> tftp.
>>> 
>>> We started having more frequent timeouts during initrd download 
>>> around the
>>> time RHEL8 became more prevalent in our environment, so we just 
>>> switched
>>> to http going forward (after CentOS/RHEL 7) since the initrd images 
>>> seemed
>>> to be on a growth trend over time.
>>> 
>>> Like you suspect, we generally found this to be a problem independent 
>>> of
>>> UEFI; it was simply that the modern hardware we were getting was more
>>> frequently coming with UEFI rather than traditional BIOS, and we 
>>> needed
>>> the newer linux releases to support the newer hardware, etc. so the
>>> situation came together basically at the same time.
>> 
>> We don't have RH's in our environment, but I suspect the initrd's are 
>> just growing larger to support more stuff (especially installers).
>> 
>> Combined with a slowdown in TFTP transfers (I've seen this the last 
>> few years), it seems to timeout
>> 
>> Unfortunately, trying http link for the initrd did not work on this HP 
>> laptop... maybe this laptop firmware does not support it...
> 
> I used to think this was a UEFI BIOS issue, but after much digging, I
> found the solution.  I posted this a few years back:
> 
> There are other issues with PXE over UEFI with syslinux.  I got it to
> work by using version 6.04_pre1 plus 3 pathes and building from source:
> 
> efi-udp-core_udp_connect-use-SubnetMask-not-StationA.patch
> efi-udp-Add-retry-disabling-UseDefaultAddress.patch
> efi-udp-Removing-the-udp_reader-efi_binding.patch
> 
> Patches are cherry-picked commits from syslinux git tree.
> 
> Fixes the decaying TFTP transfer rate problem.

Is there a reason this cannot be committed to a 6.04_pre2 or something? 
(or some PR?) If you posted this a few years back? (how old is 6.04_pre1 
???)

Maybe I should add these patches to my distro, do you have some git 
references?

Regards,

AL13N