'UEFI Memory location
I am attempting to write an x86_64 PC emulator. I was wondering in what memory location the UEFI is mapped. I know that a BIOS is usually mapped from 0xf0000-0xfffff and 0xf0000000-0xffffffff. Is UEFI mapped to the same locations?
Solution 1:[1]
UEFI is not loaded in a specific memory location. Something needs to be placed where the processor starts fetching instructions, and then SEC and PEI stages prepare for DXE to be uncompressed somewhere dynamically - loading individual PE/COFF as it goes.
The way you find out what memory regions are reserved is by calling the GetMemoryMap boot service at runtime.
You may find the documentation of the existing EDK2 virtual machine port helpful.
Solution 2:[2]
Yes, the UEFI firmware is loaded to the same locations as well as legacy BIOS. Otherwise, why is cs:ip is pointing 0xFFFFFFF0 in its initial state?
Check out the OvmfPkg in EDK II. This is an open-source UEFI firmware for virtual machines. You can load it into famous emulators like Bochs, QEMU.
You can also use VMware's EFI firmware, but in that it is proprietary, you might want to read VMware's license before you really want to proceed with it.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | unixsmurf |
| Solution 2 | Zero Tang |