Can a 32-bit processor really address 2^32 memory locations?

Question

I feel this might be a weird/stupid question, but here goes...

In the question Is NULL in C required/defined to be zero?, it has been established that the NULL

Answer 1

It depends upon the operating system. It is related to virtual memory and address spaces

In practice (at least on Linux x86 32 bits), addresses are byte "numbers"s, but most are for 4-bytes words so are often multiple of 4.

And more importantly, as seen from a Linux application, only at most 3Gbytes out of 4Gbytes is visible. a whole gigabyte of address space (including the first and last pages, near the null pointer) is unmapped. In practice the process see much less of that. See its /proc/self/maps pseudo-file (e.g. run cat /proc/self/maps to see the address map of the cat command on Linux).