From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andreas Schweigstill <andreas@schweigstill.de>
Date: Tue, 08 Jan 2008 18:51:23 +0100
Subject: [U-Boot-Users] Do we enable Interrupts in U-Boot?
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Hello!

Chetan Nanda schrieb:
> Thanks, for explaining the things,
> But how can we wait for two events simultaneously (that is also under
> a single thread of execution)? Can you give me pointer to the code ?

As mentioned before, U-Boot is not an operating system which provides
such means. It doesn't have a driver layer with file operations similar
to Linux. The only way to wait for events exactly simultaneously is
using a hardware which provides these events in one hardware register.

Usually one would poll the event sources:

...

while (1) {
	if (driver_a_check_data_available()) {
		driver_a_read_data();
	}
	if (driver_b_check_data_available()) {
		driver_b_read_data();
	}
}

if this will be implemented in an U-Boot command, you probably want
this loop also to be left, e.g. by pressing Ctrl-C:

while (!ctrlc()) {
...
}

Regards
Andreas Schweigstill

-- 
Dipl.-Phys. Andreas Schweigstill
Schweigstill IT | Embedded Systems
Schauenburgerstra?e 116, D-24118 Kiel, Germany
Phone: (+49) 431 5606-435, Fax: (+49) 431 5606-436
Mobile: (+49) 171 6921973, Web: http://www.schweigstill.de/