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

Michael Brown mcb30 at ipxe.org
Wed Jul 12 18:35:34 UTC 2017

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)?


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