Dell Inspiron 5567, Linux Mint 21.3 Virginia 64-bit, Kernel Linux 5.15.0-107-generic x86_64, Intel® Core™ i7-7500U CPU @ 2.70GHz × 4, Mesa Intel® HD Graphics 620 (KBL GT2).
demesg shows
[Firmware Bug]: No firmware reserved region can cover this RMRR [0x000000007d000000-0x000000007f7fffff], contact BIOS vendor for fixes
[ 0.139996] DMAR: [Firmware Bug]: Your BIOS is broken; bad RMRR [0x000000007d000000-0x000000007f7fffff]
BIOS vendor: Dell Inc.; Ver: 1.5.0; Product Version:
MDS CPU bug present and SMT on, data leak possible.
Firmware Bug]: ACPI region does not cover the entire command/response buffer. [mem 0xfed40000-0xfed4087f flags 0x200] vs fed40080 f80
amdgpu: TOPAZ not supported in kfd

So, it appears that all is not well though the system works well.
The existing bios file has the same date as the download available from Dell and the computer was running windows 10 at that time. It was suggested on the Dell site that installing Wine and executing it from there would safely install a new copy.
Opinions?
Are the BIOS,firmware and CPU one problem or three separate problems?
I hope this question is asked well.
Graeme

This link goes into detail about it and offers a work around: https://superuser.com/questions/1718...ly-deleting-ef
But overall this bug is more annoyance than anything to worry about.