Real Time Clock

Thomas Doerfler Thomas.Doerfler at
Mon May 11 11:45:10 UTC 2009


if I got Sebastians proposal right, he tends to convert the existing
functions proprietary to the RTC drivers into "Classic API" driver
calls, which can then be accessed through the I/O manager API. Among
others benefits, this will clean up that interface (no longer a
proprietary function set).

Accessing these drivers with the POSIX standard functions
(open/read/write/close) will then be possible without problem.

Please note: we are NOT talking about SW timers, we are taking about the
hardware device "Real-Time-Clock".

Do you have a pointer to a proper POSIX API to access such a device?


Ralf Corsepius wrote:
> Joel Sherrill wrote:
>> Sebastian Huber wrote:
>>> Hi,
>>> I tried to write a shell command to read and set the real time clock (RTC).
>>> Unfortunately this is currently impossible to achieve within the cpukit.  One
>>> solution would be to extend the default RTC driver interface in
>>> cpukit/libcsupport/include/rtc.h:
>> I don't have a problem with adding some more standard interfaces
>> to the driver.  It should be possible to do it in a way that doesn't
>> impact any existing BSP or application.
> I am not excited to see yet another proprietary method being proposed 
> related to timers.
> Instead, we should implement POSIX conformant calls with a appropriate 
> syscalls underneath.
> Ralf
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