LPC MicrocontrollersのトピックRe: LPC54S018 second attempt at encryption

LPC54S018 second attempt at encryption

827529957 — Wed, 27 Nov 2019 04:38:01 GMT

I use the routine “lpcxpresso54s018m_xip_with_secure_boot_an_demo” provided by AN12352SW to encrypt, and do the secure boot of LPC54S018 in 5 steps referring to AN12352.

1. Divide the image into two parts by modifying linker script. The demo have done it and I did not make any changes.

2. Create the image.

Note : In the case of normally boot, if I loaded the image directly, it will run successfully.

Split the image as secure-plain text and non-secure.

From the image above, the image_length equals 0x000056CC, so the total length of the image is 0x000056CC+4.

The secure-plain text image is from address 0 to address (0x000056CC+4-1) of the original image binary. This image is used to create the secure-bootable part image.
The non-secure image is from address 0x0010_0000 to the end of the original image. This image is as non-secure part image.

Create the secure bootable part image based on secure-plain text image.

Use elftosb to generate 128 bits AES key.

Use the elftosb-gui to create the secure-bootable part image.

3. Program the two parts of the image into the flash.

program secure bootable part image into Flash.

It would prompt me to add check code and I clicked 'No'.

program the non-secure part image into Flash

4. Program the 128 bits AES key to OTP.

program the AES key use blhost.

5. Program the related OTP bit fields to enable secure boot.

use blhost and the following commands to program related OTP bit fields.

blhost.exe -u 0x1fc9,0x01a2 -- efuse-program-once 12 00000010

blhost.exe -u 0x1fc9,0x01a2 -- efuse-program-once 12 00000004

finally, I reset my board, but it was failed, because there was no any print on debug consule and the debug on Keil can not check my core. I can't connect the PC and the board with SWD.

What did I do wrong？I need some help. Thanks.

Re: LPC54S018 second attempt at encryption

Alice_Yang — Thu, 28 Nov 2019 03:35:48 GMT

Hello Kunsen Chen,

Refer to the AN12352, not recommend use Jflash to program:

Have a great day,
TIC

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Re: LPC54S018 second attempt at encryption

827529957 — Thu, 28 Nov 2019 06:20:30 GMT

The reason why JFlash cannot be used is because a checksum may be added. However, I have ensure that the code programming into the chip didn't add the checksum.

At first, I used JFlash to load my code, and indeed added the checksum. I read back the flash code through JFlash and the code is as follow. Except for the red box, other data is consistent with the code file to be downloaded.

but then I cancelled the option to add the checksum, and I read the flash code through JFlash, and it did not add the checksum. I used the data comparison function of HxD for comparison, the data is completely consistent with the code file to be downloaded.

Am I right? I worry that I am doing something wrong elsewhere. Do you think my other operations are OK?

Re: LPC54S018 second attempt at encryption

Alice_Yang — Thu, 05 Dec 2019 13:48:46 GMT

Hello Kunsen,

I recommend you first completely refer to the steps in AN12352.