I wrote the ROTK fields in the CMPA now why I cant connect with a debugger?

andrewfisher — Fri, 21 May 2021 23:32:39 GMT

I am using a LPC55s28 and am tentatively trying to get secure boot working. I say tentative as it really doesn't feel like all thi info is there and it isn't even consistent in the UG UM11126.pdf

Eg pg141 fig 13 - the CMPA is at address 0x0003_E400 but on pg144 it is at 0x0009_E400!

I ran the following code (numbers changed to protect the innocent):

st = FFR_GetCustomerData(&my_flashInstance, (uint8_t *)CMPA, 0, 512); // RKTH: 3e562d88 35880e0d 0be586a3 137e5e1b e77eb765 3280a8e8 fa58f463 80227fe5 CMPA[16] = 0x11111111; CMPA[17] = 0x22222222; CMPA[18] = 0x33333333; CMPA[19] = 0x44444444; CMPA[20] = 0x55555555; CMPA[21] = 0x66666666; CMPA[22] = 0x77777777; CMPA[23] = 0x88888888; st = FFR_CustFactoryPageWrite(&my_flashInstance, (uint8_t *)CMPA, false);

Now I cant connect to the board with the debugger nor is it running my blinky code.

What have I done wrong? I didn't do anything to actually enable secure boot or lock out the debugger (or did I!)

Actually looking at fig5 pg141 the least significant words of the ROTK are not shown. Should I not have programmed them?

Re: I wrote the ROTK fields in the CMPA now why I cant connect with a debugger?

Alice_Yang — Mon, 24 May 2021 10:27:47 GMT

Hello andrewfisher,

As I reply you on your another thread, ->> 0x009DE00 is right.

And about configure CMPA, we need very be careful.

So if you want to use secure boot, recommend refer to

https://www.nxp.com.cn/docs/en/application-note/AN12283.pdf

Alice

topic Re: I wrote the ROTK fields in the CMPA now why I cant connect with a debugger? in LPC Microcontrollers

I wrote the ROTK fields in the CMPA now why I cant connect with a debugger?

Re: I wrote the ROTK fields in the CMPA now why I cant connect with a debugger?