components/TimeServer/src/plat/pc99/plat.c

/*
 * Copyright 2019, Data61, CSIRO (ABN 41 687 119 230)
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <autoconf.h>
#include <assert.h>
#include <stdio.h>
#include <sel4/sel4.h>
#include <sel4/arch/constants.h>
#include <camkes.h>
#include <platsupport/plat/timer.h>
#include <utils/util.h>
#include <sel4utils/sel4_zf_logif.h>
#include <simple/simple.h>
#include <sel4utils/arch/tsc.h>

#include "../../plat.h"

static uint64_t tsc_frequency = 0;

uint64_t the_timer_tsc_frequency()
{
    return tsc_frequency;
}

// We declare this with a weak attribute here as we would like this component to work
// regardless of whether the assembly declared this to have a simple template or not.
// Having this as weak allows us to test for this at run time / link time
void camkes_make_simple(simple_t *simple) __attribute__((weak));
extern uint64_t tsc_freq_hint;
void plat_pre_init(void)
{
    // Attempt to detect the presence of a simple interface and try and get the
    // tsc frequency from it
    tsc_frequency = 0;
    if (camkes_make_simple) {
        simple_t simple;
        camkes_make_simple(&simple);
        tsc_frequency = x86_get_tsc_freq_from_simple(&simple);
    }
    tsc_freq_hint = tsc_frequency;

}

void plat_post_init(ltimer_t *ltimer)
{
    if (tsc_frequency == 0) {
        // failed to detect from bootinfo for whatever reason, rely on the pit calibration
        tsc_frequency = ltimer_pit_get_tsc_freq(ltimer);
    }
}