Easy way to merge bootloader and application RTT output

RE: Easy way to merge bootloader and application RTT output

nrbrook — Wed, 09 Mar 2022 16:27:02 GMT

To prevent the linker adding the section to the output, you can just use

.rtt (NOLOAD):
{
} > RAM

in the linker script, then it does not need removing with objcopy.

RE: Easy way to merge bootloader and application RTT output

Fabien Comte — Fri, 10 Apr 2020 14:24:31 GMT

Ok I found, in Makefile.common

$(NO_ECHO)$(OBJCOPY) -R .rtt -O binary $< $@

and

$(NO_ECHO)$(OBJCOPY) -R .rtt -O ihex $< $@

RE: Easy way to merge bootloader and application RTT output

Fabien Comte — Fri, 10 Apr 2020 14:14:51 GMT

Hello,

How can I integrate objcopy cleanly in the flow under Windows please ?

RE: Easy way to merge bootloader and application RTT output

nrbrook — Tue, 03 Dec 2019 12:37:58 GMT

2 major SDK versions later, still not implemented – this would have saved me a fair bit of time!

RE: Easy way to merge bootloader and application RTT output

nrbrook — Tue, 03 Dec 2019 12:14:02 GMT

Additionally, on app start SEGGER_RTT_Init is run again which leads to loss of output from bootloader. To prevent this, you can modify SEGGER_RTT_INIT in SEGGER_RTT.c to check the memory is initialised (just first character here but you could check the string equals "SEGGER"):

void SEGGER_RTT_Init (void) {
    if(_SEGGER_RTT.acID[0] != 'S') {
        _DoInit();
    }
}

RE: Easy way to merge bootloader and application RTT output

abhipray — Thu, 08 Nov 2018 00:14:02 GMT

thanks for sharing this! very helpful.

RE: Easy way to merge bootloader and application RTT output

ekrashtan — Tue, 20 Mar 2018 18:24:58 GMT

I'm not familiar with Segger Studio, but every time when you observe different behaviour in power-on and reset sequences - you should check variables initialization. Ensure all your global variables have "static" type.

RE: Easy way to merge bootloader and application RTT output

ShannonPahl — Mon, 19 Mar 2018 22:12:38 GMT

I've done something similar for Segger Studio and it works.

However, the power on scenario seems to only show the app's output. Any other reset and I see the merged output. Any insights into this ?

Steps for Segger Studio:

1. Add the .rtt section in RAM in flash_placement.xml for both projects (bootloader and app). Make sure its just after the .vectors_ram section:

2. Make sure both projects have the same RAM_START address in *.emProject

3. Refactor out the Segger configuration from both sdk_config.h's to a new file and add the following #define to the new file. Then include the file into both sdk_config.h's.

#define SEGGER_RTT_SECTION ".rtt"

4. Since the Segger buffers were previously in a zeroed section and now they are not, add two lines to the main.c of both projects:

NRF_SECTION_DEF(rtt, uint8_t);

int main(void)
{
memset(NRF_SECTION_START_ADDR(rtt), 0, NRF_SECTION_LENGTH(rtt));
...

RE: Easy way to merge bootloader and application RTT output

Jared — Sun, 25 Feb 2018 04:15:02 GMT

ekrashtan this has been super handy. Thank you for posting this.

RE: Easy way to merge bootloader and application RTT output

ekrashtan — Sat, 10 Feb 2018 12:13:44 GMT

Ok, one important update. Current version of nrfutil can't remove RAM content from HEX file, so if you want to use resulting *.hex for creating DFU ZIP image, create it from elf with objcopy's key '-R .rtt'
Otherwise, you can see this unfixed issue: github.com/.../100

RE: Easy way to merge bootloader and application RTT output

tesc — Thu, 08 Feb 2018 13:36:58 GMT

Hi,

Thank you for the feedback and suggestions. I have notified the SDK team.

Regards,
Terje