[syslinux] CPU usage while at syslinux boot prompt

[Ferenc Wagner]

"H. Peter Anvin" <hpa at zytor.com> writes:

> The *only* device that we have to talk to that we can guarantee
> getting an interrupt for is the keyboard, the rest of the devices
> *have* to be handled by polling, via an idle loop.
> [...]
> I guess I might put a HLT in *as an option* (because people *will*
> complain that the serial port loses characters)

I get this very annoying dropout from the Xen hypervisor, and wonder:
is this a problem of common serial hardware not supporting interrupt
generation or a deeper theoretical one?  Can't you do reliable
interrupt driver serial IO on common UARTs by principle?  Doesn't the
Linux kernel do this?
-- 
Thanks,
Feri.