I have a PCIe 4x card in PCIe slots, which does a communication to card, before “linux” command is loaded. I had an implementation of PCIe communication which perfectly works for BIOS based system. However, when i configure he GRUB2 for EFI system and install it, the same communication to PCIe board does not occur. It is not able to read/write BAR2 address and giving communication error.
I have following questions in this regard -
a) Is any changes in GRUB2 for UEFi system for PCIe communication
b) TLP packet generated for PCIe communication uses 32-bit or 64-bit address?. Because BIOS uses 32-bit address only for PCIe TLP.