OpenRTX/lib/miosix-kernel/miosix/arch/common/drivers/stm32_sgm.h

91 lines
3.3 KiB
C++

/***************************************************************************
* Copyright (C) 2017 by Matteo Michele Piazzolla *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* As a special exception, if other files instantiate templates or use *
* macros or inline functions from this file, or you compile this file *
* and link it with other works to produce a work based on this file, *
* this file does not by itself cause the resulting work to be covered *
* by the GNU General Public License. However the source code for this *
* file must still be made available in accordance with the GNU General *
* Public License. This exception does not invalidate any other reasons *
* why a work based on this file might be covered by the GNU General *
* Public License. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#include "board_settings.h"
#define PRESERVE __attribute__((section(".preserve")))
namespace miosix {
/**
* Possible causes for an STM32 reset
*/
enum ResetReason
{
RST_LOW_PWR=0,
RST_WINDOW_WDG=1,
RST_INDEPENDENT_WDG=2,
RST_SW=3,
RST_POWER_ON=4,
RST_PIN=5,
RST_UNKNOWN=6,
};
/**
* Driver for the STM32F2 and STM32F4 backup SRAM, here used as
* SafeGuard Memory, that is, a memory whose value is preseved across resets.
*/
class SGM
{
public:
/**
* \return an instance of this class (singleton)
*/
static SGM& instance();
/**
* Temporarily disable writing to the safeguard memory.
* By deafult, from reset to when the contrsuctor of this class is called
* the safeguard memory is not writable. After the constructor is called,
* the safeguard memory is writable.
*/
void disableWrite();
/**
* Make the safeguard memory writable again, after a call to disableWrite()
*/
void enableWrite();
/**
* Return the cause of the last reset of the microcontroller
*/
ResetReason lastResetReason() { return lastReset; }
private:
ResetReason lastReset;
SGM(const SGM&)=delete;
SGM& operator=(const SGM&)=delete;
SGM();
void readResetRegister();
void clearResetFlag();
};
}