Qualcomm Firmware Engineer interview questions

1. Implement alloc and free function in c, the alloc function always return a pointer to a 1k memory chunk, the free release this memory chunk you can not use malloc, calloc, realloc and free. 2. You need to implement a timer module that has a function timer that gets as input a time and function pointer and call the function when the time is expire, what is the best data structure to use to get the next time in o(1) 2.

How to multiply two numbers without using multiplication? In as much detail as you can, describe the C compilation process