Softdevice hanging at startup

RE: Softdevice hanging at startup

Jørgen Holmefjord — Thu, 17 Sep 2020 12:30:31 GMT

Here is a link to the Bootloader and DFU modules documentation. If the bootloader came with the module, you should check with the module manufacturer to make sure they are using an unmodified bootloader from our SDK, and which SDK version they have used. You can also erase the module and build your own from our SDK, see the DFU bootloader examples documentation.

RE: Softdevice hanging at startup

Hugo Habicht — Thu, 17 Sep 2020 12:26:09 GMT

Hi Jørgen,

I did not program any bootloader but it may have been in the module we are using and we certainly want to use it.

Can you point me to documentation where all what you mentioned above is described in detail?

Regards,

RE: Softdevice hanging at startup

Jørgen Holmefjord — Thu, 17 Sep 2020 12:12:37 GMT

[quote user="Hugo Habicht"]Also, does the hrs example include a boot loader?[/quote]

No, the bootloader is a separate example that is built and flashed separately from the application.

[quote user="Hugo Habicht"]WHAT IS THE SOFTDEVICE DOING IN ADDRESS 0x2ff6? [/quote]

This is WFE/sleep operation.

[quote user="Hugo Habicht"]So what (hardware input) makes the softdevice going into bootloader mode? Software is identical, so that cannot be the problem.[/quote]

The bootloader will enter DFU mode under the following conditions:

No valid application is present.
SoftDevice is activated and a valid application is present. In that case, the bootloader expects that an application update can be requested by the host.
Entering DFU mode is triggered by one of the optional sources:
- Button (NRF_BL_DFU_ENTER_METHOD_BUTTON),
- Pin reset (NRF_BL_DFU_ENTER_METHOD_PINRESET),
- Special value in GPREGRET register (NRF_BL_DFU_ENTER_METHOD_GPREGRET),
- Request from the application written to the settings page (NRF_BL_DFU_ENTER_METHOD_BUTTONLESS).

In addition:

If one of the following conditions occurs, the bootloader enters the DFU mode:

no application is installed,
the integrity check fails,
there is no settings page.

If you did not build and flash the bootloader with the valid settings page for the application, the bootloader will enter DFU mode. If you did not intend to use the bootloader, please erase the chip using "nrfjprog --eraseall" command before flashing your application.

RE: Softdevice hanging at startup

Hugo Habicht — Thu, 17 Sep 2020 10:56:10 GMT

Hi Jørgen,

it seems the softdevice is going into bootloader mode, I can see "DfuTarg" when I scan for bluetooth devices when it's hanging.

So what (hardware input) makes the softdevice going into bootloader mode? Software is identical, so that cannot be the problem.

Regards,

RE: Softdevice hanging at startup

Hugo Habicht — Thu, 17 Sep 2020 09:06:06 GMT

Hi Jørgen,

I compiled the original unchanged example of your SDK HRS. Works on the Nordic EVM. Bur it does not even reach main() on our board. So that leads to the question:

WHAT CAN PREVENT THE SOFTDEVICE FROM CALLING main()?

What pin, signal, power supply, configuration etc. would do that?

And you did not answer my original question:

WHAT IS THE SOFTDEVICE DOING IN ADDRESS 0x2ff6? WHAT IS IT WAITING FOR? COULD YOU PLEASE FIND OUT?

Or should we be rather looking into the ESP32?

Regards,

RE: Softdevice hanging at startup

Hugo Habicht — Thu, 17 Sep 2020 06:12:08 GMT

Hi Jørgen,

last time I checked Arm architecture specifies LSB as bit 0, so in this case your softdevice is waiting for an RTC2 interrupt. Why is that?

Also, does the hrs example include a boot loader? If yes, where can I find information about same? The MBR/ Bootloader documentation is sparse; I could only find addresses but no structure contents or description or what happens at startup. Or do I have to search all that in the source myself?

Regards,

RE: Softdevice hanging at startup

Jørgen Holmefjord — Wed, 16 Sep 2020 18:27:24 GMT

The IRQ numbers are defined in the MDK, in the file modules\nrfx\mdk\nrf52840.h:

typedef /* ======================================= Reset_IRQn                = -15, NonMaskableInt_IRQn       = -14, HardFault_IRQn            = -13, MemoryManagement_IRQn     = -12,

BusFault_IRQn             = -11,

UsageFault_IRQn           = -10, SVCall_IRQn               =  -5, DebugMonitor_IRQn         =  -4, PendSV_IRQn               =  -2, SysTick_IRQn              =  -1, /* ========================================== POWER_CLOCK_IRQn          =   0, RADIO_IRQn                =   1, UARTE0_UART0_IRQn         =   2, SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0_IRQn= SPIM1_SPIS1_TWIM1_TWIS1_SPI1_TWI1_IRQn= NFCT_IRQn                 =   5, GPIOTE_IRQn               =   6, SAADC_IRQn                =   7, TIMER0_IRQn               =   8, TIMER1_IRQn               =   9, TIMER2_IRQn               =  10, RTC0_IRQn                 =  11, TEMP_IRQn                 =  12, RNG_IRQn                  =  13, ECB_IRQn                  =  14, CCM_AAR_IRQn              =  15, WDT_IRQn                  =  16, RTC1_IRQn                 =  17, QDEC_IRQn                 =  18, COMP_LPCOMP_IRQn          =  19, SWI0_EGU0_IRQn            =  20, SWI1_EGU1_IRQn            =  21, SWI2_EGU2_IRQn            =  22, SWI3_EGU3_IRQn            =  23, SWI4_EGU4_IRQn            =  24, SWI5_EGU5_IRQn            =  25, TIMER3_IRQn               =  26, TIMER4_IRQn               =  27, PWM0_IRQn                 =  28, PDM_IRQn                  =  29, MWU_IRQn                  =  32, PWM1_IRQn                 =  33, PWM2_IRQn                 =  34, SPIM2_SPIS2_SPI2_IRQn     =  35, RTC2_IRQn                 =  36, I2S_IRQn                  =  37, FPU_IRQn                  =  38, USBD_IRQn                 =  39, UARTE1_IRQn               =  40, QSPI_IRQn                 =  41, CRYPTOCELL_IRQn           =  42, PWM3_IRQn                 =  45, SPIM3_IRQn                =  47 } IRQn_Type;

enum { ARM Cortex-M4 Specific Interrupt Numbers ======================================== */ /*!< -15 Reset Vector, invoked on Power up and warm reset */ /*!< -14 Non maskable Interrupt, cannot be stopped or preempted */ /*!< -13 Hard Fault, all classes of Fault */ /*!< -12 Memory Management, MPU mismatch, including Access Violation and No Match */ /*!< -11 Bus Fault, Pre-Fetch-, Memory Access Fault, other address/memory related Fault */ /*!< -10 Usage Fault, i.e. Undef Instruction, Illegal State Transition */ /*!< -5 System Service Call via SVC instruction */ /*!< -4 Debug Monitor */ /*!< -2 Pendable request for system service */ /*!< -1 System Tick Timer */ nrf52840 Specific Interrupt Numbers ========================================== */ /*!< 0 POWER_CLOCK */ /*!< 1 RADIO */ /*!< 2 UARTE0_UART0 */ 3, /*!< 3 SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0 */ 4, /*!< 4 SPIM1_SPIS1_TWIM1_TWIS1_SPI1_TWI1 */ /*!< 5 NFCT */ /*!< 6 GPIOTE */ /*!< 7 SAADC */ /*!< 8 TIMER0 */ /*!< 9 TIMER1 */ /*!< 10 TIMER2 */ /*!< 11 RTC0 */ /*!< 12 TEMP */ /*!< 13 RNG */ /*!< 14 ECB */ /*!< 15 CCM_AAR */ /*!< 16 WDT */ /*!< 17 RTC1 */ /*!< 18 QDEC */ /*!< 19 COMP_LPCOMP */ /*!< 20 SWI0_EGU0 */ /*!< 21 SWI1_EGU1 */ /*!< 22 SWI2_EGU2 */ /*!< 23 SWI3_EGU3 */ /*!< 24 SWI4_EGU4 */ /*!< 25 SWI5_EGU5 */ /*!< 26 TIMER3 */ /*!< 27 TIMER4 */ /*!< 28 PWM0 */ /*!< 29 PDM */ /*!< 32 MWU */ /*!< 33 PWM1 */ /*!< 34 PWM2 */ /*!< 35 SPIM2_SPIS2_SPI2 */ /*!< 36 RTC2 */ /*!< 37 I2S */ /*!< 38 FPU */ /*!< 39 USBD */ /*!< 40 UARTE1 */ /*!< 41 QSPI */ /*!< 42 CRYPTOCELL */ /*!< 45 PWM3 */ /*!< 47 SPIM3 */

Bit 4 of NVIC_ISPR1 would correspond to SPIM2_SPIS2_SPI2_IRQn or RTC2_IRQn, depending on if you started counting from 0 or from 1. None of these should be related to the softdevice.

As far as I know, the softdevice should not run startup code, it only handles forwarding of interrupts from MBR to application (see Exception model). The SystemInit code is found in the MDK as well (modules\nrfx\mdk\system_nrf52840.c).

RE: Softdevice hanging at startup

Hugo Habicht — Wed, 16 Sep 2020 12:28:20 GMT

Hi Jørgen,

I believe the SDK is version nRF5_SDK_17.0.0_9d13099 although I could not confirm that in any of the source files; there are no version numbers in them.

The example is the pca10056 board from the same SDK; we never installed an older version or ported anything.

Softdevice version is s140_nrf52_7.0.1.

Thanks for the hint with the NVIC register. But since this is ARM core documentation, where is the Nordic assignment for the nRF52840? Could not find anything in the data sheet. What is bit 4 in NVIC_ISPR1?

And why would the startup code (unfortunately located in the softdevice) wait for an interrupt?!? Or am I missing something?

Regards,

RE: Softdevice hanging at startup

Jørgen Holmefjord — Wed, 16 Sep 2020 12:06:38 GMT

Which SDK and softdevice versions are you using? Is this a "clean project" from an SDK release, or something you have ported from a previous SDK version?

0xE000E204 is not a "Nordic Black Box", this is one of the ARM Cortex M4 NVIC_ISPR (Interrupt Set-Pending Registers) registers.

RE: Softdevice hanging at startup

Hugo Habicht — Tue, 15 Sep 2020 17:13:28 GMT

Hi Jørgen,

changed to the RC oscillator but that did not make a difference. Could have guessed that before because the oscillator init is done in main().

In my case the softdevice is hanging BEFORE reaching main() (see first post).

So since your documentation contains nothing about what is happening inside the softdevice (only API) you have to help me on that one. Any ideas? What is it waiting for in address 0x2ff6?

I believe it has to be hardware related because the software (basically the BLE hrs example) is running fine on the Nordic EVM.

Regards,

p.s.: seems to be waiting for something to happen in bit 4 of a register on address 0xe000e204 which is not documented (another Nordic black box or I am too stupid to find it).

RE: Softdevice hanging at startup

Jørgen Holmefjord — Tue, 15 Sep 2020 12:40:16 GMT

The RC oscillator is accurate enough to be used for BLE after calibration, see Clock source in the softdevice documentation.

Just make sure you set the softdevice clock config accuracy to 500PPM, and use the CTIV and TEMP_CTIV configs from above link.

The drawback of using the RC oscillator, compared to the crystal, is higher current consumption due to the lower accuracy and need for calibration.

RE: Softdevice hanging at startup

Hugo Habicht — Tue, 15 Sep 2020 12:33:59 GMT

Hi Jørgen,

for a test to confirm / rule out the crystal the rc would work but my understanding is that it is not accurate enough for BLE. Is that correct?

Regards,

RE: Softdevice hanging at startup

Jørgen Holmefjord — Tue, 15 Sep 2020 12:17:47 GMT

Hi,

The documentation for the softdevices can be found here. Source code is not available.

If you are in doubt if the issue is caused by an issue with the crystal, try changing the project to use the internal RC oscillator. If there is a crystal problem, this test will tell you.

Best regards,
Jørgen

RE: Softdevice hanging at startup

Hugo Habicht — Mon, 14 Sep 2020 14:51:08 GMT

Looking at the EVM when the software is hanging I'd say you are right about the crystal oscillator. Crystal capacitance we have is 9pF, capacitors are 12pF to ground. Series resistance is 90k, nRF52840 data sheet says 100k max. Do you think that's too tight? Layout is as good as you'd get it I'd say...

RE: Softdevice hanging at startup

Hugo Habicht — Mon, 14 Sep 2020 14:29:10 GMT

... working on that at the moment (thanks for the hint !). Not easy though, small probe capacitance seems to prevent startup...

RE: Softdevice hanging at startup

awneil — Mon, 14 Sep 2020 14:08:01 GMT

and have you verified that it is working?

RE: Softdevice hanging at startup

Hugo Habicht — Mon, 14 Sep 2020 13:42:21 GMT

No, 32kHz crystal is on the board.

RE: Softdevice hanging at startup

awneil — Mon, 14 Sep 2020 13:39:39 GMT

32 KHz crystal ... ?

https://devzone.nordicsemi.com/f/nordic-q-a/46564/error-133-0x85-gatt-error-on-nrf52840/185126#185126

https://devzone.nordicsemi.com/f/nordic-q-a/46564/error-133-0x85-gatt-error-on-nrf52840/185362#185362