Regami Solutions Firmware Engineer interview questions

I had applied online. There were 5 rounds of interview. Initially there was a online test with negative marking. Later, 2 rounds of technical rounds were there. They go deep in c programming pointers, arrays and data structures. Then questions were asked on multilevl threading, rtos, bsp, bit manipulation, boot loaders , and interface related questions. Questions was challenging with scenarios, and was tough to crack 2nd and 3rd round. 4th round was mostly on system level understanding and the roles and responsibilities. Finally hr discussions with onboarding link. Took me 2 weeks to complete the process.