83680c41db
Store the RTC value in the .uninitialized section, but make sure to flank it with some known values. That way we can determine if the RTC value has been initialized, or if it's random uninitialized garbage. As part of this, add a `common_hal_rtc_init()` routine to determine if the value is correct, or reset it to 0 if it is not valid. Signed-off-by: Sean Cross <sean@xobs.io>
83 lines
3.3 KiB
C
83 lines
3.3 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2019 Nick Moore for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <stdlib.h>
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#include "py/obj.h"
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#include "py/runtime.h"
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#include "lib/timeutils/timeutils.h"
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#include "shared-bindings/rtc/__init__.h"
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#include "supervisor/port.h"
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#include "supervisor/shared/translate.h"
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// This is the time in seconds since 2000 that the RTC was started.
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__attribute__((section(".uninitialized"))) static uint32_t rtc_offset[3];
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// These values are placed before and after the current RTC count. They are
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// used to determine if the RTC count is valid. These randomly-generated values
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// will be set when the RTC value is set in order to mark the RTC as valid. If
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// the system crashes or reboots, these values will remain undisturbed and the
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// RTC offset will remain valid.
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//
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// If Circuit Python is updated or these symbols shift around, the prefix and
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// suffix will no longer match, and the time will no longer be valid.
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#define RTC_OFFSET_CHECK_PREFIX 0x25ea7e2a
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#define RTC_OFFSET_CHECK_SUFFIX 0x2b80b69e
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void common_hal_rtc_init(void) {
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// If the prefix and suffix are not valid, zero-initialize the RTC offset.
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if ((rtc_offset[0] != RTC_OFFSET_CHECK_PREFIX) || (rtc_offset[2] != RTC_OFFSET_CHECK_SUFFIX))
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rtc_offset[1] = 0;
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}
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void common_hal_rtc_get_time(timeutils_struct_time_t *tm) {
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uint64_t ticks_s = port_get_raw_ticks(NULL) / 1024;
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timeutils_seconds_since_2000_to_struct_time(rtc_offset[1] + ticks_s, tm);
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}
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void common_hal_rtc_set_time(timeutils_struct_time_t *tm) {
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uint64_t ticks_s = port_get_raw_ticks(NULL) / 1024;
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uint32_t epoch_s = timeutils_seconds_since_2000(
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tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec
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);
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rtc_offset[1] = epoch_s - ticks_s;
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// Set the prefix and suffix in order to indicate the time is valid. This
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// must be done after the offset is updated, in case there is a crash or
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// power failure.
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rtc_offset[0] = RTC_OFFSET_CHECK_PREFIX;
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rtc_offset[2] = RTC_OFFSET_CHECK_SUFFIX;
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}
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int common_hal_rtc_get_calibration(void) {
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return 0;
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}
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void common_hal_rtc_set_calibration(int calibration) {
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mp_raise_NotImplementedError(translate("RTC calibration is not supported on this board"));
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}
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