Jo's Embedded Serial File System (for Standard Serial NOR-Flash)
for Standard (Serial) NOR-Flash
Just think of very simple things like language data: on a “very small”
Embedded Device (not something “big” like an Embedded Linux, but something
that can run with small batteries for years): it is commonly integrated
“somewhere in the code”.
Difficult to change! But if the language data is in files,
changes are easy. Same for graphics, setups, everything…
It even allows to change the firmware on the Embedded Device from many different sources!
Think of Embedded Devices, that even can get their latest firmware by themselves! E.g. over
WiFi, Mobile Internet, Bluetooth, UART, Radio-Link, …
Suddenly all options are open! And if you have concerns about
the security: don’t worry: problem already solved, as you’ll see later..
The main problem for “very small devices” – until now – was the “File System”: everybody knows “FAT”, “NTFS”, … but have you ever thought of a file system on a small chip? Or even inside of a CPU? No problem, with the right Software. This is why I wrote
“JesFs – Jo’s Embedded Serial File System“
[Image: 4MB JesFs on 2x3 mm]
My daily work ist the IoT. Because I did not find any really practical solution, I decided to create my own one. “Robustness”, “Security” and “Small Footprint” were my design constraints.
JesFs was designed for use in the “Real World” and for use with standard Serial NOR-Flash memories, like the M25R-Series, used on nRF52840-DK, nRF52832 and the CC13xx/CC26xx Launchpads, which is available up to 16 MB, or even more…
Some Basics about JesFs:
int16_t fs_open(FS_DESC *pdesc, char* pname, uint8_t flags);
int32_t fs_read(FS_DESC *pdesc, uint8_t *pdest, uint32_t anz);
int16_t fs_write(FS_DESC *pdesc, uint8_t *pdata, uint32_t len);
int16_t fs_close(FS_DESC *pdesc);
int16_t fs_delete(FS_DESC *pdesc);
int16_t fs_rewind(FS_DESC *pdesc);
int16_t fs_rename(FS_DESC *pd_odesc, FS_DESC *pd_ndesc);
uint32_t fs_get_crc32(FS_DESC *pdesc);
int16_t fs_check_disk(void cb_printf(char *fmt, ...), uint8_t *pline, uint32_t line_size);
int16_t fs_format(uint32_t f_id);
int16_t fs_start(uint8_t mode);
void fs_deepsleep(void);
int16_t fs_info(FS_STAT *pstat, uint16_t fno);
void fs_sec1970_to_date(uint32_t asecs, FS_DATE *pd);
Many technical devices work reliable for years and years and no one cares about them. But if they fail, there is always the question: WHAT WENT WRONG?
This is, where the JesFs could become extremely useful.
Read more: BlackBox_Eval.pdf
Wide Voltage Range (1.6v-3.6V) and Ultra-Low-Power Standby:
Built with SES (V6.22a ()) and SDK 17.1.0 (: Later Versions of SES require changed project settings!!!)
Set Macro $SDK_ROOT where to find the SDK in SES -> Tools -> Options -> Building: e.g.: "Global Macros": "SDK_ROOT=C:\nordic\nRF5_SDK_17.1.0_ddde560"
Set Platform Macro with I/O-Pins (see tb_tools.h)
Optionally fix Problem with nrf_clock() (see docu tb_tools_nrf52.c/.h)