nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Tue, 17 Oct 2023 12:12:08 GMT

Thank you, I appreciate your help with this.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Tue, 17 Oct 2023 11:12:46 GMT

Excellent! Thanks for the update. I understand you used UICR for debugging. Just want to add that you can use our general-purpose retention registers (GPREGRET) for the same in case you were not aware.

Retention registers are retained across soft resets (ie NVIC_SystemReset())

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Tue, 17 Oct 2023 10:17:19 GMT

Bingo. Yes, that is it. I am using part of UICR to signal the bootloader to do an update and that was being reset. Ironically, for debugging.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Tue, 17 Oct 2023 09:50:34 GMT

The NRF_UICR->PSELRESET is a non-volatile register that enables pin reset on P0.21. If this register is rewritten every time the application boots, it suggests that the UICR registers are being erased between reboots. To further debug this, please read the values at addresses 0x10001204 and 0x10001208 when you reach the breakpoint shown in your previous screenshot.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Tue, 17 Oct 2023 09:48:38 GMT

ie it will hit the system reset every time.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Tue, 17 Oct 2023 09:43:34 GMT

It is this:

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Tue, 17 Oct 2023 09:28:16 GMT

You are right, I misread the address and thought it was in the bootloader's address range. Still, the instruction you pointed to should not cause a reset. This is why I want you to debug the application to find out what is actually triggering the reset. Could you do this? It might be something simple, like a code assert that invokes the error handler in the Error module.

Both the bootloader and application invoke system_nrf52.c through the startup code.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Tue, 17 Oct 2023 09:17:55 GMT

This is not so, as that address is in the region of the application. I believe this is a call to system_init in system_nrf52.c. Does this not suggest that the bootup code has been replicated in the application? If so, will that cause an issue?

I should also say that I relocated the application from 0x3e000 to 0x5e000 as the bootloader had grown due to debugging.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Mon, 16 Oct 2023 17:44:59 GMT

This line is executed by the bootloader upon startup and should not trigger a reset. Please place a breakpoint in the main() function of the application (not bootloader) to verify if the program execution reaches the application or not.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Mon, 16 Oct 2023 14:11:22 GMT

It fails here:

--- system_nrf52.c -- 99 -----------------------------------
}
/* Workaround for Errata 32 "DIF: Debug session automatically enables TracePort pins" found at the Errata document
for your device located at https://www.nordicsemi.com/DocLib */
if (errata_32()){
    F000F9BD    bl 0x00073F8C <errata_32>
    4603        mov r3, r0
    2B00        cmp r3, #0
    D005        beq 0x00073C24
--- system_nrf52.c -- 104 ----------------------------------
CoreDebug->DEMCR &= ~CoreDebug_DEMCR_TRCENA_Msk;
    4B96        ldr r3, =0xE000EDF0
    68DB        ldr r3, [r3, #12]
    4A95        ldr r2, =0xE000EDF0
    F0237380    bic r3, r3, #0x01000000
    60D3        str r3, [r2, #12]

at this line:

    4A95        ldr r2, =0xE000EDF0

which is addres 0x73c1c

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Mon, 16 Oct 2023 12:20:12 GMT

I see it now. So, I assume the function pointer correctly points to the application's reset handler. You can single-step with your debugger to confirm.

[quote userid="4240" url="~/f/nordic-q-a/104680/nrf52832-custom-bootloader-fails-at-bootjump---sdk15-3-soft-device-s132_nrf52_6-1-1_softdevice/450537"]Please start a debug session with your application project and check if the program reaches main().[/quote]

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Mon, 16 Oct 2023 12:08:50 GMT

app entry is a function pointer:

typedef void (*pFunction)(void);

It can be seen at the top of the last screenshot.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Mon, 16 Oct 2023 11:53:41 GMT

Please start a debug session with your application project and check if the program reaches main(). The screenshot shows that a reset occurred sometime after appEntry() was executed, but it is not possible to determine the cause from these images.

Also, please show how appEntry() is implemented.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Mon, 16 Oct 2023 10:57:46 GMT

Having reread and followed your suggestions, this is the before and after state of the registers:

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Mon, 16 Oct 2023 07:20:51 GMT

[quote user="SCrowe"]Have removed NO_VTOR_CONFIG flag.[/quote]

Which project did you remove the flag from? The bootloader must have this flag set if it is going to make calls into the MBR, as your stack trace shows.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Fri, 13 Oct 2023 15:59:21 GMT

Another clue? Seems to hang here, which is different than it was doing before.

Have removed NO_VTOR_CONFIG flag.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Fri, 13 Oct 2023 15:05:28 GMT

[quote userid="73652" url="~/f/nordic-q-a/104680/nrf52832-custom-bootloader-fails-at-bootjump---sdk15-3-soft-device-s132_nrf52_6-1-1_softdevice/450336"]Looks like that is already present in the bootloader.[/quote]

I meant to ask if you could try to *remove* this flag from your application project.

[quote userid="73652" url="~/f/nordic-q-a/104680/nrf52832-custom-bootloader-fails-at-bootjump---sdk15-3-soft-device-s132_nrf52_6-1-1_softdevice/450339"]At what point? I can insert a breakpoint at the bootjump and take a snapshot?[/quote]

After you have called the function which is supposed to start the application so I can see where the program ends up.

Also, can you show how you've implemented this function?

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Fri, 13 Oct 2023 14:35:34 GMT

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Fri, 13 Oct 2023 14:28:14 GMT

"Can you post a screenshot of the CPU registers?"
At what point? I can insert a breakpoint at the bootjump and take a snapshot?

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Steven — Fri, 13 Oct 2023 14:24:41 GMT

Looks like that is already present in the bootloader.

RE: nRF52832 Custom Bootloader fails at bootjump - SDK15.3, soft device s132_nrf52_6.1.1_softdevice

Vidar Berg — Fri, 13 Oct 2023 13:02:42 GMT

Hello,

I suspect it may be a problem with the interrupt forwarding. Applications using the Softdevice will usually have interrupts forwarded from the MBR->Softdevice as described in the 'Interrupt forwarding to the application' section of the Softdevice specification.

If you are using Segger Embedded Studio, you can try to build the application without the NO_VTOR_CONFIG flag.

The application will then receive the interrupts directly (Important: this will only work when the application is not using the Softdevice).

[quote user=""]The firmware reboots after the jump to the application, looks like an address in the soft device.[/quote]

Can you post a screenshot of the CPU registers?

Best regards,

Vidar