Simple Persistent Embedded Configurator (S.P.E.C.)

This library provides a simple way to load, store and change MCUs configuration parameters run-time.

Dependencies

This library relies on the ArenaAllocator for memory management. Make sure to initialize the allocator handler before the S.P.E.C. handler initialization.

Usage

The first thing you must do is declare and initialize the arena allocator handler as shown in the usage section here. After that, declare the configuration handler using struct SpecHandler and initialize it by using the spec_api_init() function.

const uint32_t CFG_VERSION = 0xB16B00B5U;
const struct SpecParameter DEFAULT_CFG[3U] = {
	{ .data = (int8_t[]){0x1F}, .size = 1U },
	{ .data = (int8_t[]){0x2F}, .size = 1U },
	{ .data = (int8_t[]){0x3F}, .size = 1U },
};

struct ArenaAllocatorHandler arena;
struct SpecHandler cfg;

arena_allocator_api_init(&arena);
spec_api_init(&spec, &area, DEFAULT_CFG, 3U, NULL, NULL, CFG_VERSION);

We need to declare the DEFAULT_CFG because it will be used if no configuration is stored inside the MCU. DEFAULT_CFG is an array of parameters; it contains addresses to some data and their sizes.

Setting or getting parameters is quite simple. Use spec_api_get() and spec_api_set() as follows.

/*! Getting the 1st parameter */
int8_t var = 0;
spec_api_get(&spec, 0, &var, sizeof(var));

/*! Setting the 1st parameter */
var = get_new_var_value();
spec_api_set(&spec, 0, &var, sizeof(var));

In order to load or store configurations, you need to give the appropriate functions to read and write data to the desired NVM.

/*!
 * 'read_nvm' and 'write_nvm' are implemented by the user.
 *   - enum SpecReturnCode read_nvm(size_t, void*, size_t) { }
 *   - enum SpecReturnCode write_nvm(size_t, const void*, size_t) { }
 **/
spec_api_init(&cfg, &arena, DEFAULT_CFG, 3U, read_nvm, write_nvm);

Examples

Note

Examples are work-in-progress

For more examples check the examples folder.