>the toolchain used for building is some customized thing. I work in automotive.
That's because in automotive the microcontrollers are more complex, with multiple cores of different types doing different things, so the build process is more complex therefore the final binary goes through several steps like patching various calibration data, FPGA bit-streams, cyptopgraphic keys, fuses, debug data, etc. but even so, those custom toolchains still call a comercial compiler via command line using some perl/python scrips at the end of the day.
You can script same steps with IAR or Keil if you wish, their compiler support the same command line functionality, except that in IoT we mostly used their solution 'as-is' since it worked well with their debuggers out of the box meaning quicker time to market.
Automotive development has a lot more crust in general due to legacy, safety, legal, plus bs stuff like the entire Autosar stack needing to be added to each build whether you need it all or not so a lot of inefficiencies build up over time due to this inertia leading to some insanely complex and lengthy build processes.
That's because in automotive the microcontrollers are more complex, with multiple cores of different types doing different things, so the build process is more complex therefore the final binary goes through several steps like patching various calibration data, FPGA bit-streams, cyptopgraphic keys, fuses, debug data, etc. but even so, those custom toolchains still call a comercial compiler via command line using some perl/python scrips at the end of the day.
You can script same steps with IAR or Keil if you wish, their compiler support the same command line functionality, except that in IoT we mostly used their solution 'as-is' since it worked well with their debuggers out of the box meaning quicker time to market.
Automotive development has a lot more crust in general due to legacy, safety, legal, plus bs stuff like the entire Autosar stack needing to be added to each build whether you need it all or not so a lot of inefficiencies build up over time due to this inertia leading to some insanely complex and lengthy build processes.