TLV storage

A simple TLV based storage solution for EEPROM-like storage devices.

Composition

The solution is composed of 3 main parts:

• TLV storage management
• Data types definitions
• Demo storage application

Storages types (data models)

TLV data model properties

• PRODUCT_ID - Unique identifier for the product
• PRODUCT_NAME - Human-readable product name
• SERIAL_NO - Serial number of the device
• PCB_NAME - Name of the printed circuit board
• PCB_REVISION - Revision number of the PCB
• PCB_PROD_DATE - Production date in YY-MM-DD format
• PCB_PROD_LOCATION - Production location identifier
• PCB_SN - Serial number of the PCB
• MAC_ADDR_* - MAC address for network interfaces, may be specified multiple times for different interfaces
• XTAL_CALDATA - Board/radio XTAL calibration data
• RADIO_CALDATA - Radio calibration data
• RADIO_BRDDATA - Radio board data

Fixed fields structure data model properties

• PRODUCT_ID - Unique identifier for the product
• PRODUCT_NAME - Human-readable product name
• SERIAL_NO - Serial number of the device
• PCB_NAME - Name of the printed circuit board
• PCB_REVISION - Revision number of the PCB
• PCB_PROD_DATE - Production date in YY-MM-DD format
• PCB_PROD_LOCATION - Production location identifier
• PCB_SN - Serial number of the PCB
• MAC_ADDR - MAC address of device

Legacy TLV data model properties

• PRODUCT_ID - Unique identifier for the product
• SERIAL_NO - Serial number of the device
• PCB_NAME - Name of the printed circuit board
• PCB_REVISION - Revision number of the PCB
• PCB_PROD_DATE - Production date in YY-MM-DD format
• PCB_PROD_LOCATION - Production location identifier
• PCB_SN - Serial number of the PCB
• GENERIC_ADDR_* - MAC address for network interfaces, may be specified multiple times for different interfaces
• XTAL_CALIBRATION_DATA - Board/radio XTAL calibration data
• RADIO_CALIBRATION_DATA - Radio calibration data

Usage

List all supported properties:

tlvs -l

Get all properties:

tlvs -g

Set and get specific properties:

tlvs -s PRODUCT_NAME="My Device" SERIAL_NO="SN12345"
tlvs -g PRODUCT_NAME SERIAL_NO

Setting parametrized MAC address properties:

tlvs -s MAC_ADDR_eth0=aa:bb:cc:dd:ee:ff MAC_ADDR_eth1=11:22:33:44:55:66
tlvs -g MAC_ADDR_eth0 MAC_ADDR_eth1

Import and export properties from and to file:

tlvs -s [email protected]
tlvs -g [email protected]

Get properties using a configuration file:

tlvs -g @config.txt

Example of config.txt content:

PRODUCT_NAME
SERIAL_NO
PCB_REVISION
MAC_ADDR_eth0

Set properties using a configuration file:

tlvs -s @config.txt

Example of config.txt content:

PRODUCT_NAME=Example Device
PRODUCT_ID=EX-01
SERIAL_NO=SN12345
PCB_NAME=MainBoard
PCB_REVISION=0002
PCB_PROD_DATE=24-03-15
MAC_ADDR_eth0=aa:bb:cc:dd:ee:ff
MAC_ADDR_wlan0=11:22:33:44:55:66

Use existing storage or create a new one in a file. Size option is required when creating a new storage (e.g., 8KB), but optional when using existing storage as size is detected automatically:

tlvs -F new_storage.bin -S 8192

Specify storage location using MTD partition name (requires CONFIG_IO_MTD):

# Using MTD partition name
tlvs -F part:eeprom-data -g
tlvs -F part:product-info -s SERIAL_NO="SN12345"

The part:name format resolves MTD partition names from /proc/mtd.

Build

Build the utility with optional debug output, custom storage file and size:

make [DEBUG=1] [CONFIG_TLVS_FILE=/path/to/storage.bin] [CONFIG_TLVS_SIZE=size]

Option	Description
DEBUG=1	Enables debug build, to produce detailed operation information
CONFIG_TLVS_FILE=/path/to/storage.bin	Specifies a default storage file path
CONFIG_TLVS_SIZE=size	Specifies a default storage size (in bytes)
CONFIG_TLVS_COMPRESSION=<0-9>	Specifies compression level preset (default: 9 extreme)
CONFIG_TLVS_COMPRESSION_NONE=y	Disables compression support (default LZMA compression)
CONFIG_IO_MTD=1	Enables MTD partition storage backend
CONFIG_IO_MMAP=1	Uses memory-mapped I/O storage backend

Storage Backend Selection

The build system automatically selects one storage backend based on configuration:

1. MTD Backend (char-mtd.c) - Selected when CONFIG_IO_MTD=1

   • Optimized for MTD (Memory Technology Device) flash storage
   • Uses MTD-specific ioctls for device information
   • Handles MTD device characteristics properly

2. Memory-Mapped Backend (char-mmap.c) - Selected when CONFIG_IO_MMAP=1

   • Maps storage file directly to memory
   • Best for systems with sufficient RAM

3. Buffered Write-Back Backend (char-bwb.c) - Default fallback

   • Pre-allocates heap buffer for storage
   • Intelligent write-back only writes changed data
   • Works with regular files

Install the utility with optional installation prefix:

make install [PREFIX=/path/to/installation]

When compression is enabled packages is linked against liblzma, therefore liblzma-dev should be available in libs search path or sysroot.

Next

• Add more compression algorithms options
• Add support for compressing all fields
• Add bindings for python and LUA languages