This application shows how to wait for events and register a timer. More...

#include <Uefi.h>
#include <Library/UefiLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <UEFIStarter/core.h>

Functions
void	callback (EFI_EVENT event, void *context)
	Callback function for the timer. More...

void	do_gettime_tests ()
	Prints the current date/time info and timing capabilities of the UEFI runtime service's GetTime(). More...

void	do_timestamp_tests ()
	Compares the internal get_timestamp() against the UEFI service's timer functions. More...

void	do_event_tests ()
	Registers events to wait for. More...

INTN EFIAPI	ShellAppMain (UINTN argc, CHAR16 **argv)
	Main function, gets invoked by UEFI shell. More...

Detailed Description

This application shows how to wait for events and register a timer.

Author: Richard Nusser

Copyright: 2017-2018 Richard Nusser

License: GPLv3 (see http://www.gnu.org/licenses/)

See also: https://github.com/rinusser/UEFIStarter

Function Documentation

◆ callback()

void callback	(	EFI_EVENT	event,
		void *	context
	)

Callback function for the timer.

Contains a Print() call that may crash a Virtualbox VM. In current builds it does not, but it used to for some reason. Calling Print() in a timer callback is just for demonstration anyway.

Parameters

event	(unused) the triggered timer event
context	(unused) the triggered timer event's context data

◆ do_gettime_tests()

void do_gettime_tests ( )

Prints the current date/time info and timing capabilities of the UEFI runtime service's GetTime().

This shows resolutions of 1Hz on all tested systems, the nanosecond field seems to be always empty. This makes GetTime() useless for timing e.g. animation frames.

◆ do_timestamp_tests()

void do_timestamp_tests ( )

Compares the internal get_timestamp() against the UEFI service's timer functions.

The timer interval is 1s, so the internal timestamp should increase by 1 for each Hz of CPU frequency.

◆ do_event_tests()

void do_event_tests ( )

Registers events to wait for.

One of the events is a callback function, it will get called asynchronously whenever the event is fired. The called handler currently prints to the console - this used to hang when executed inside a VirtualBox VM.

◆ ShellAppMain()

INTN EFIAPI ShellAppMain	(	UINTN	argc,
		CHAR16 **	argv
	)

Main function, gets invoked by UEFI shell.