From: Steve Litt via talk <talk@gtalug.org>
D. Hugh Redelmeier via talk said on Fri, 25 Oct 2024 11:51:42 -0400
Linux was a simple hack based on Unix.
Not really. Everything starts small, but Linux was quite large by the time it was really useful for something other than Linux development.
Use it for your boot drive if you can. UEFI is a mess even in its specifications, hardware vendors' botched implementation makes it worse, and its attack surface is breathtaking compared to MBR. There's nothing stopping you from using the boot drive MBR and the rest of your drives the very nice GPT (but not UEFI).
As far as I know, every machine that has UEFI implements MBR booting through UEFI. In particular, the "CSM" implements BIOS calls. I don't think that you are avoiding vulnerabilities using MBR on a machine with UEFI. MBR's primary partitions are actually described by a few entries in the last bytes of the boot sector. There is only room for four entries so the additionally hack of "extended partition" was invented. Where does you boot loader live in MBR? The primary boot-loader loads a secondary boot-loader from the partition to be booted. Where does the secondary boot loader (which must fit in a single block!) get the rest of the machinery for booting? Normally from an list of absolute block numbers (very fragile). UEFI has a less hacky answer: the ESP is a full fledged file-system allowing files to be used. These hacks can mean perplexing behaviour unless you understand how it is all put together. Secure Boot, which comes with UEFI, is a little bit of a comfort. Not perfect.