[ipxe-devel] [PATCH 1/1] efi: provide possibility to disable cpu_nap

[Michael Brown]

On 12/07/17 19:15, Heinrich Schuchardt wrote:
> Nope. Interrupts are not supported by U-Boot. To get them running every
> architecture implementation would have to be changed.
> 
> U-Boot simply uses a call inside the waiting loop to check if new data
> is available.
> 
> E.g. in UEFI WaitForEvent it will check if new data becomes available on
> the serial console or on the network interface inside a loop. In
> CheckEvent it will do the same. If data becomes available it will fire
> the UEFI event.

OK.  What facility does U-Boot provide to allow the CPU to sleep (i.e. 
to allow an idling program to avoid running with 100% CPU usage)?

Michael