4 ms·
The 16 bit mode stuff and the guest OS probes are after what I'm asking, not before.
by dataflow 1y ago
The 16 bit mode stuff and the guest OS probes are after what I'm asking, not before.
- akdev1l 1y agoNo 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
- speed_spread 1y agoA 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.