Read .bin firmware file from PN7462

[tuannguyen-aiot]

Hello NXP technical support.
Can I read the firmware .bin file from the PN7462?
Is there a document that locks the firmware so it can't be read?

[tuannguyen-aiot]

Hi @Julián_AragónM ,

How many ways are there to read the .bin or .axf firmware file of PN7462? Can you provide me with detailed information?

[Julián_AragónM]

Hi @tuannguyen-aiot,

The NFC Cockpit application supports the "Dump EEPROM" action, which stores the complete user area of the PN7462 family IC EEPROM into a binary file. This can be used to generate a backup of all settings or to transfer optimized settings onto another board or into own software.

Alternatively, you can read registers, or single byte from the EEPROM.

Also, the NFC Reader Library for the PN7462 includes an example for system services invocation, more information about this example is under chapter 9.12 (PN7462AU_ex_phSystemServices) from the PN7462 family Quick Start Guide.

You can also try reading the EEPROM and Flash through phhalEeprom_Read & phhalFlash_Read (PN7462 Code Read/Write Protection Levels & IAP).

Best regards,
Julián.

[tuannguyen-aiot]

Hi @Julián_AragónM ,
When I lock the flash memory read/write function, can I OTA the PN7462 in another way?

[Julián_AragónM]

Hi @tuannguyen-aiot,

If phhalSysSer_USB_PrimaryDnldConfig() is used, on subsequent boots, the ROM boot never enters ROM primary download mode, even if DWL_REQ pin and USB_VBUS pin is high.

This feature is typically used after development and flashing of secondary downloader in the flash memory, for subsequent code/data upgrades. In this case, you should refer to the  AN10995 - LPC1100 secondary bootloader (with software). The secondary Bootloader project described here is implemented with the M0 LPC and many concepts described could be reused also in PN7462AU secondary project.

If phhalSysSer_OTP_SecrowConfig() is used, any flash programming after locking the flash results in hard fault.

I hope you find this helpful.

Best regards,
Julián.

[tuannguyen-aiot]

Hello @Julián_AragónM ,
I want to be unable to read. The same write is allowed in the case of <nn> = 01 as recorded here.
What can I do

[Julián_AragónM]

Hi @tuannguyen-aiot,

Unfortunately, as I've said, there is not a lot of information for code protection for the PN7462.

You can look into this community post for some information about the ROM API (phhalSysSer_USB_PrimaryDnldConfig
https://community.nxp.com/t5/MCUXpresso-General/Code-Protection/m-p/985976

This command is used to irreversibly disable the ROM primary download feature. On subsequent boots, the ROM boot never enters ROM primary download mode, even if DWL_REQ pin and USB_VBUS pin is high. This feature is typically used after development and flashing of secondary downloader in the flash memory, for subsequent code/data upgrades.

You can find the code snippet through the User Manual (EEPROM Management of PN746X and PN736X).

I apologize for any inconveniences this may cause.

Best regards,
Julián.

[Julián_AragónM]

Hi @tuannguyen-aiot,

By "locking" the firmware, do you mean a way to authenticate and encrypt?

The PN7462 uses SWD technology, which has read/write access to user flash memory, user EEPROM memory, user RAM memory, and peripheral registers. You can look into the SWD capabilities in chapter 4.4 (SWD) of the PN7462 family HW user manual (UM10858).

You can either lock SWD access, or flash memory from a HW level for read/write code protection. Please help me looking into chapters 3.3.1.2 (SWD access permissions) & 3.3.1.3 (Code write protection) from the PN7462 family Software User Manual (UM10913).

Please be careful, as once the SWD interface is disabled, it is not possible to enable it anymore.

I hope you find this helpful!

Best regards,
Julián

[tuannguyen-aiot]

Hi @Julián_AragónM ,

I want to keep the code and still write the program to flash memory.

Block reading flash memory, EEPROM from any way. What can I do.

[Julián_AragónM]

Hi @tuannguyen-aiot,

I apologize for the inconveniences this may cause, but the PN7462 does not have a high customization grade for read/writing flash. If you are interested in adding an additional security layer to a project using a programmable NFC microcontroller, please consider looking into the PN7642, which is a SESIP-certified security system optimized for secure key storage and cryptography.

You can find more information about this device here: Single chip solution with high performance NFC reader.

Best regards,
Julián.