Partition Table

The partition_table module is a build script tool that parses the partition table description file ptab.json and generates the header file ptab.h. This header file contains a series of macro definitions related to partition information, which can be included in projects to obtain partition details.

The partition table can describe the address mapping for all memory types, including NOR Flash, NAND Flash, eMMC, TF cards, PSRAM, and on-chip SRAM. Each board has its own ptab.json that describes the partition information for that board. Any project compiled for that board must follow the address mapping defined by the partition table. Projects can also use a custom ptab.json to override the board’s default configuration.

Enabling the Partition Table

Select Use partition table to manage all memory layout in the middleware to enable the partition table feature:

You also need to define the following switch in your project’s Kconfig.proj. This snippet is already included in all example projects.

#APP specific configuration.
config CUSTOM_MEM_MAP
    bool 
	select custom_mem_map
	default y if !SOC_SIMULATOR

Partition Table Syntax

The partition table description file ptab.json is a text file in JSON format. It follows standard JSON syntax and can be edited with any text editor. There are two versions of the partition table syntax: 1.0 and 2.0. The 2.0 version simplifies the syntax compared to 1.0, making it easier to understand and maintain. It is recommended that new projects adopt the 2.0 syntax. For detailed syntax, refer to Partition Table Syntax Version 1.0 and Partition Table Syntax Version 2.0.

Dumping ftab.bin

After a project is built, the build directory contains ftab.bin, the binary Flash Table generated from the partition table. Use sdk.py ftab-dump to inspect this file in a readable form when checking boot addresses, image sizes, XIP addresses, or DFU image flags.

Run the command in an exported SDK environment:

source ./export.sh

On Windows PowerShell, run:

./export.ps1

From the project directory, dump the first build_*/ftab.bin found under that project:

sdk.py ftab-dump

To avoid ambiguity when multiple board build directories exist, pass the file path explicitly:

sdk.py ftab-dump --path build_<board_name>/ftab.bin

The default output is a table view. JSON output is also available for scripts:

sdk.py ftab-dump --path build_<board_name>/ftab.bin --format json

Options:

Option	Description
`-p, --path <path>`	Path to `ftab.bin`. If omitted, `sdk.py` searches for `build_*/ftab.bin` in the current project directory.
`-f, --format <format>`	Output format: `table` or `json`. The default is `table`; use `json` for machine-readable output.

The table output contains three sections:

Section	Description
Partition Table Entries	Flash Table partition entries, including storage base address, partition size, XIP or execution base address, and flags.
Image Description Table	Image metadata used by DFU and boot flows, including image length, block size, flags such as `AUTO` or `COMPRESS`, and whether the entry is valid.
Image Index Table	Running image pointers for each core image slot, such as HCPU, LCPU, bootloader, and boot image.