UEFI iPXE quirks with SuperMicro sensors

[AdamWu]

I found a peculiar problem with iPXE.
I have burned iPXE UEFI rom to an Intel i210 NIC for iSCSI booting to Windows on a SuperMicro X10SDV motherboard.

Everything seems to work perfectly, except when I try to install sensor monitor software -- I got no readings at all!
I even logged on to IPMI interface, it too shows all sensors unavailable.

After quite some tweaking, I managed to bring back all sensors in a very quirky and funny way:
1. Set iPXE NIC boot as first boot device.
2. But at boot time, press F11 invoke boot menu, boot to "built-in UEFI shell".
3. Stay in the shell prompt for 3~10 seconds, just do nothing.
4. Refresh sensor in the IPMI interface, all sensors now have readings.
5. Type "exit" at UEFI shell, the boot automatically proceeds to iPXE, and everything boots just as usual.
6. Sensor readings continue to be available until the next reboot.

It seems to me that, maybe, iPXE's UEFI code somehow missed some procedure, which initializes the system sensor readings.

By diverting to the system UEFI shell first, which does properly initialize the sensors, then proceed to iPXE, the problem is cured.