Hi
I still have some questions:
- First; Section 2.3.3 Table 2 Indicates how a BIN file is stored. Am I right? If yes, thinking in this, for example, to my builded image is as follows:
a. My offset value is (address 0x28) 0x0160.
b. The Image_length is 0x000056B4.
c. So total length of the image is 0x000056B8.
Now this section indicates:
The secure-plain text image is from address 0 to address (total length of the image – 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 (0x1010_0000 - 0x1000_0000) to the end of the original image. This image is as non-secure part image.
Here is the doubt. It means that secure-plain text will be until address 0x000056B7 right? And so that, what will be the non-secure image?
Here is a reforcement of my doubt; A project that has been done before and that was test on LPC54018 is 2,172 kB of length so that, how I could split the image? It is posible to split image at will?
I have an idea about how it could be based on the las question, but I’m not pretty sure:
If secure section is 192 kB, we could split image like that from 0 to 2FFFF address(0x30000 of length) and set it in that section, so the remains of the image(0x1EEA64 of length) will be set in non-secure from 0x10100000 to 0x102EEA63 address. So that there is 0xD0000(1MB – 192kB) between secure-plain and non-secure plain, what happens with stack pointer? It will be automatically jump from 0x10030000 to 0x10100000 address? Am I right with my guess about spliting image?
- To créate the secure bootable part image based on secure-plain text image it means run alftosb file by command window right. In my case I do this:
a. Windows+r->cmd
b.Descargas\SDK_2.5.0_LPCXpresso54S018\middleware\mcu-boot\bin\Tools\elftosb\win\elftosb.exe --keygen 128 aes128_key.key on a command window.
It was right?
- Finally, I need to get pretty clear about write OTP in the demo example, so this is my question, doing the AN12352.pdf file’s steps, the OTP will be written? If this is yes I will need to build secure image of my projects with this aes128_key.key generated by elftosb.exe in this demo? If not when I get my final firmware how I will set the key on the OTP section?
Thanks.
Best Regards
Oscar Niño