CentOS - Oct 2019 - UEFI and PXE

Chris Adams writes:
> Once upon a time, isdtor <isdtor at gmail.com> said:
> > 11:06:51.413549 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none],
proto UDP (17), length 390)
> >     10.1.2.2.67 > 255.255.255.255.68: [udp sum ok] BOOTP/DHCP,
Reply, length 362, xid 0x4007adc6, Flags [Broadcast] (0x8000)
> >           Your-IP 10.1.2.57
> >           Server-IP 10.1.2.1                                     
<--
> >           Client-Ethernet-Address 00:1b:21:d8:69:1c
> >           file "linux-install/bootx64.efi"
> >           Vendor-rfc1048 Extensions
> >             Magic Cookie 0x63825363
> >             DHCP-Message Option 53, length 1: ACK
> >             Server-ID Option 54, length 4: 10.1.2.2
> >             Lease-Time Option 51, length 4: 43200
> >             Subnet-Mask Option 1, length 4: 255.255.255.0
> >             Default-Gateway Option 3, length 4: 10.1.2.250
> >             Domain-Name-Server Option 6, length 8: 10.1.2.2
> >             Hostname Option 12, length 5: "client"
> >             Domain-Name Option 15, length 20: "foo.bar.com"
> >             NTP Option 42, length 8: 10.1.2.2
> >             RN Option 58, length 4: 21600
> >             RB Option 59, length 4: 37800
> >             TFTP Option 66, length 11: "10.1.2.1"           
<--
> >             END Option 255, length 0
> 
> I do see a couple of differences - main one is that my boot file is in
> option 67, not the BOOTP "file" field.  Also, my option 66 is a
> hostname, not an IP.  I don't know how you tell ISC DHCP to use option
> 67 instead of the file field, but maybe that could trigger different
> client behavior?
> 
> More odd is that dnsmasq is adding a null terminator to both options 66
> and 67.  My UEFI PXE clients seem to accept it just fine though.
Yes, it looks like I'm out of luck and need to find a newer machine to test
this with. Moving the tftp server works to an extent - server boots right into a
grub prompt.

I went over the linux-poweredge archives and found this:

https://lists.us.dell.com/pipermail/linux-poweredge/2015-May/049810.html

In particular:
| 2.      Don't waste time w/ a R*10, the UEFI PXE boot code is buggy!  It
misinterprets the NBP filename (DHCP option 67).  That's an old Intel bug;
they fixed it years ago in their BIOS PXE implementation.  I'm guessing it
was resurrected in their UEFI PXE implementation.
| 
| Most all NIC vendors (Intel, Broadcom, etc) use the Intel reference
implementation for PXE.

Once upon a time, isdtor <isdtor at gmail.com>
said:
> Yes, it looks like I'm out of luck and need to find a newer machine to
test this with. Moving the tftp server works to an extent - server boots right
into a grub prompt.
Weird.  I have a couple of Intel-based systems that do UEFI PXE boot
okay, but they're much newer than the 11th gen PowerEdge (I have some of
those still in service but they're not running UEFI mode).  Also,
they're client-type systems, not servers (a Thinkpad notebook and an
Intel NUC), so possibly different firmware base.

I vaguely remember in the distant past having some kind of problem like
this, and I think on those systems, I used a boot floppy (yes, that long
ago!) with gPXE on it.
-- 
Chris Adams <linux at cmadams.net>

Chris Adams writes:
> Once upon a time, isdtor <isdtor at gmail.com> said:
> > Yes, it looks like I'm out of luck and need to find a newer
machine to test this with. Moving the tftp server works to an extent - server
boots right into a grub prompt.
> 
> Weird.  I have a couple of Intel-based systems that do UEFI PXE boot
> okay, but they're much newer than the 11th gen PowerEdge (I have some
of
> those still in service but they're not running UEFI mode).  Also,
> they're client-type systems, not servers (a Thinkpad notebook and an
> Intel NUC), so possibly different firmware base.
> 
> I vaguely remember in the distant past having some kind of problem like
> this, and I think on those systems, I used a boot floppy (yes, that long
> ago!) with gPXE on it.
Not too happy to revive this old thread ...

Has anyone managed to UEFI/PXE boot CentOS6? I managed to find newer hw and have
this working perfectly with CentOS7. With 6, however, I again cannot boot beyond
a grub prompt.

CentOS7 bootx64.efi does not work for CentOS6 as it complains "kernel too
old". Booting with CentOS6 /boot/efi/EFI/redhat/grub.efi, and the older
style pxe config file as per
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/installation_guide/s1-netboot-pxe-config-efi
results in a grub (legacy) prompt on the target machine.