main.c

#include "printf.h"
#include "flash.h"
#include "spiffs.h"

#define LOG_PAGE_SIZE 128 // can't read more than this in one go
static u8_t spiffs_work_buf[LOG_PAGE_SIZE*2];
static u8_t spiffs_fds[32*4];
static u8_t spiffs_cache_buf[(LOG_PAGE_SIZE+32)*4];

static spiffs fs;

static s32_t my_spiffs_read(u32_t addr, u32_t size, u8_t *dst) {
//	printf("read(%x, %d, %p)\n", addr, size, dst);
	read_page(addr, dst, size);

	return SPIFFS_OK;
}
static s32_t my_spiffs_write(u32_t addr, u32_t size, u8_t *src) {
//	printf("write(%x, %d, %p)\n", addr, size, src);
	write_page(addr, src, size);

	return SPIFFS_OK;
}
static s32_t my_spiffs_erase(u32_t addr, u32_t size) {
//	printf("erase(%x, %d)\n", addr, size);
	erase_block(addr, size);

	return SPIFFS_OK;
}

void my_spiffs_mount(void) {
	spiffs_config cfg;
	cfg.phys_size = FLASH_SIZE; // use all spi flash
	cfg.phys_addr = 0; // start spiffs at start of spi flash
	cfg.phys_erase_block = BLOCK_4K; // according to datasheet
	cfg.log_block_size = BLOCK_4K; // let us not complicate things
	cfg.log_page_size = LOG_PAGE_SIZE; // as we said
	cfg.hal_read_f = my_spiffs_read;
	cfg.hal_write_f = my_spiffs_write;
	cfg.hal_erase_f = my_spiffs_erase;
	int res = SPIFFS_mount(&fs,
		&cfg,
		spiffs_work_buf,
		spiffs_fds,
		sizeof(spiffs_fds),
		spiffs_cache_buf,
		sizeof(spiffs_cache_buf),
		0);

	printf("mount res: %i\n", res);

	if (res < 0) {
		printf("SPIFFS_format\n");
		SPIFFS_format(&fs);

		my_spiffs_mount();
	}
}

static void test_spiffs(void) {
	char buf[12];
	// Surely, I've mounted spiffs before entering here
	spiffs_file fd = SPIFFS_open(&fs, "my_file", SPIFFS_CREAT | SPIFFS_TRUNC | SPIFFS_RDWR, 0);
	if (SPIFFS_write(&fs, fd, (u8_t *)"Hello world", 12) < 0) printf("errno %i\n", SPIFFS_errno(&fs));
	SPIFFS_close(&fs, fd);
	fd = SPIFFS_open(&fs, "my_file", SPIFFS_RDWR, 0);
	if (SPIFFS_read(&fs, fd, (u8_t *)buf, 12) < 0) printf("errno %i\n", SPIFFS_errno(&fs));
	SPIFFS_close(&fs, fd);
	printf("--> %s <--\n", buf);
}

int main(void) {
	printf("erasing flash…\n");
	erase_block(0, FLASH_SIZE);

	printf("mounting…\n");
	my_spiffs_mount();

	printf("testing…\n");
	test_spiffs();
}