nes-proj/platform/galileo/contiki-conf.h
Andre Guedes e4ff61ff6c galileo: Support for rtimer library
This patch adds support for rtimer library on Galileo's platform.

We use the PIT to implement the rtimer platform dependent
functionalities. We chose the PIT for mainly two reason: I) its
configuration is very simple II) it has a high frequency which
provides us a good clock resolution (requirement from rtimer
library).

Since we keep track of the number of ticks in software, we define
rtimer_clock_t type as uint64_t. This gives us a good amount of time
til the variable overflows. For instance, a 32-bit type would overflow
in about one hour for high clock resolution (~ 1us).

The rtimer clock frequency (RTIMER_ARCH_SECOND) is setup to 1 kHz.
There is no technical matter regarding this value. It is just an
initial guess.

Just for the record, we might want to use HPET in future to
implement the rtimer library since it seems to be more appropriate.
The reason why we don't use it at this moment is that, in order to
configure it, we need support for ACPI 2.0 which we don't. Once we
have use-cases for the rtimer library we'll probably replace PIT
by HPET or any other timer more suitable for the job.
2015-12-21 08:06:14 -02:00

52 lines
2.0 KiB
C

/*
* Copyright (C) 2015, Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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*/
#ifndef CONTIKI_CONF_H
#define CONTIKI_CONF_H
#include <inttypes.h>
#define CLOCK_CONF_SECOND 128
typedef unsigned long clock_time_t;
typedef uint64_t rtimer_clock_t;
#define RTIMER_ARCH_SECOND 1024
#define RTIMER_CLOCK_LT(a, b) ((int64_t)((a) - (b)) < 0)
/* We define the following macros and types otherwise Contiki does not
* compile.
*/
#define CCIF
#define CLIF
typedef unsigned short uip_stats_t;
#endif /* CONTIKI_CONF_H */