> modern x86 processors can’t boot into BIOS mode anymore
This is false. They still can and happily will. Issue is more about vendor not shipping a CSM image. A modern x86 processor will happily run real DOS just fine.
Thank you for the correction! I saw multiple news articles several years ago saying that Intel would be dropping support for BIOS mode by the end of 2020, but it appears they've been dragging their feet. In the meantime, they seem to have been making moves in other ways, such as not supporting BIOS mode when booting with integrated graphics on 11th gen processors ( https://www.asus.com/us/support/FAQ/1045467 ).
You might get this all the time, but I saw your username and thought no way that's the old palm guy. But I clicked on your profile, and you are the old palm guy!
I used your apps back when I had a Tungsten T5, and Treo 680. :)
That's probably because it doesn't have a traditional VBIOS.
...which makes me wonder whether it's possible for the community to write one, given how much docs and source code Intel have released for their GPUs. Of course, how VGA-compatible it is is another thing to consider.
That depends on what one means by "booting into BIOS mode". CSM is a shim than makes UEFI firmware look like BIOS to the OS (or, well, bootloader) and to x86 code in various option ROMs, so you are always booting into UEFI.
Really booting without UEFI being involved in the process would require completely different firmware image.
This is false. They still can and happily will. Issue is more about vendor not shipping a CSM image. A modern x86 processor will happily run real DOS just fine.