/*
* NVRAM.h - Byte-wise storage for Virtual Pages.
* Original Copyright (c) 2017 Frank Holtz. All right reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file NVRAM.h
* @brief Byte-wise storage for Virtual Pages.
*
* @defgroup NVM Nonvolatile Memory
* @ingroup internals
* @details Nonvolatile Memory Class
* @{
*/
#pragma once
#include "Flash.h"
#include "VirtualPage.h"
#include <Arduino.h>
/**
* @class NVRAMClass
* @brief Nonvolatile Memory
*/
class NVRAMClass
{
public:
//----------------------------------------------------------------------------
/** Constructor. */
NVRAMClass() {};
//----------------------------------------------------------------------------
/** Initialize Class */
void begin() {};
//----------------------------------------------------------------------------
/** Deinitialize Class */
void end() {};
//----------------------------------------------------------------------------
/** NVM available space in bytes
* @return Number of bytes
*/
uint16_t length() const;
//----------------------------------------------------------------------------
/** Read a block of bytes
* @param[in] *dst Write bytes to given pointer
* @param[in] idx First NVM address to read
* @param[in] n Number of bytes to read
*/
void read_block(uint8_t *dst, uint16_t idx, uint16_t n);
//----------------------------------------------------------------------------
/** Read a byte
* @param[in] idx NVM Address to read
* @return Byte from given address
*/
uint8_t read(const uint16_t idx);
//----------------------------------------------------------------------------
/** Write a block
* @param[in] *src Read bytes from given pointer
* @param[in] idx First NVM address to write
* @param[in] n Number of bytes to write
* @return success
*/
bool write_block(uint8_t *src, uint16_t idx, uint16_t n);
//----------------------------------------------------------------------------
/** Write a byte
* @param[in] idx NVM Address to write
* @param[in] value Byte to write
* @return success
*/
bool write(const uint16_t idx, uint8_t value);
//----------------------------------------------------------------------------
/** Preserve the number of bytes in NVM log for time critical writes. Runtime
* up to 5000ms!
* @param[in] number Bytes to preserve, can 0 to find out free log space
* @return Bytes available for writing
*/
int write_prepare(uint16_t number);
//----------------------------------------------------------------------------
/** lear log if full and prepare released pages for faster reallocation.
* Runtime up to 5000ms!
* @param[in] write_preserve Byte to preserve
*/
void clean_up(uint16_t write_preserve);
private:
// Return a virtual page
uint32_t *get_page();
// Get actual log position
uint16_t get_log_position(uint32_t *vpage);
// Read a byte from page
uint8_t get_byte_from_page(uint32_t *vpage, uint16_t log_start,
uint16_t log_end, uint16_t idx);
// switch a page
uint32_t *switch_page(uint32_t *old_vpage, uint16_t *log_start,
uint16_t *log_end);
};
/** Variable to access the NVRAMClass */
extern NVRAMClass NVRAM;
/** @} */