55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
/*
|
|
* SPDX-License-Identifier: LGPL-3.0-or-later
|
|
* Copyright (C) 2020 Daniel Thompson
|
|
*/
|
|
|
|
#ifndef NPVRAM_H_
|
|
#define NPVRAM_H_
|
|
|
|
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
/*! \brief Pseudo Non-Voltatile RAM
|
|
*
|
|
* This is a data structure that can be placed in the first available
|
|
* RAM location. It survives reset but not power down. It can be used
|
|
* to share information between the bootloader and the main
|
|
* application.
|
|
*/
|
|
struct pnvram {
|
|
uint32_t header; //!< Validation word - 0x1abe11ed
|
|
uint32_t offset; //!< Number of seconds since the epoch
|
|
uint32_t uptime; //!< Device uptime in milliseconds
|
|
uint32_t reserved[4];
|
|
uint32_t footer; //!< Validation word - 0x10adab1e
|
|
};
|
|
|
|
#define PNVRAM_HEADER 0x1abe11ed
|
|
#define PNVRAM_FOOTER 0x10adab1e
|
|
|
|
#ifdef NRF52832_XXAA
|
|
static volatile struct pnvram * const pnvram = (void *) 0x200039c0;
|
|
#endif
|
|
|
|
static inline void pnvram_init(struct pnvram *p)
|
|
{
|
|
memset(p, 1, sizeof(*p));
|
|
|
|
p->header = PNVRAM_HEADER;
|
|
p->footer = PNVRAM_FOOTER;
|
|
}
|
|
|
|
static inline bool pnvram_is_valid(volatile struct pnvram * const p)
|
|
{
|
|
return p->header == PNVRAM_HEADER && p->footer == PNVRAM_FOOTER;
|
|
}
|
|
|
|
static inline void pnvram_add_ms(volatile struct pnvram * const p, uint32_t ms)
|
|
{
|
|
if (pnvram_is_valid(p))
|
|
p->uptime += ms;
|
|
}
|
|
|
|
#endif /* NPVRAM_H_ */
|