backup.c

/*
 * Copyright (c) 2016, Devan Lai
 *
 * Permission to use, copy, modify, and/or distribute this software
 * for any purpose with or without fee is hereby granted, provided
 * that the above copyright notice and this permission notice
 * appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/rtc.h>
#include <libopencm3/stm32/pwr.h>

#include "backup.h"

#ifndef DBL_TAP_REG
// defined by linker script
extern uint32_t _board_dfu_dbl_tap[];
#define DBL_TAP_REG   _board_dfu_dbl_tap[0]
#define DBL_TAP_MAGIC 0xf01669ef  // From tinyuf2's board_api.h
#endif

void backup_write(enum BackupRegister reg, uint32_t value) {
    DBL_TAP_REG = value;
}

uint32_t backup_read(enum BackupRegister reg) {
    return DBL_TAP_REG;
}