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by dataflow 383 days ago
The 16 bit mode stuff and the guest OS probes are after what I'm asking, not before.
2 comments

No it is not. The “first instruction in the BIOS” is 16 bit mode code when dealing with an x86 VM.

A virtual environment doesn’t even really need any BIOS or anything like that.

You can feel free to test with qemu direct kernel booting to see this skips a lot of delay without even having to use a specialized hypervisor like firecracker

A bare VM may not have a BIOS, it's just partitioning supported by the host CPU and OS. The emulation of the legacy PC hardware stack for conventional OS compatibility is a separate thing. If the guest OS is custom-designed to launch in a bare VM with known topology it can boot very, very fast.