Add generic makefiles for Linux C code

[teodutu]

Add generic Linux makefiles with default compilation recipes and flags. They cover the following use cases:

• creating a single executable using multiple files (single.mk);
• creating multiple executables, each based on a single source code file (multiple.mk).

For other use cases, use linux.mk and create a custom makefile.

The makefiles are based on those used in the "Hardware-Software Interface" course, which were added here: systems-cs-pub-ro/iocla#89.

[razvand]

@teodutu , please add that lengthier description from the PR in the commit message.

[razvand]

I added comments on using variables. And likely using defs.mk for very simple definitions.

[razvand]

Some small comments. Then this can be approved and merged.

[razvand]

See my comments. Please also include a debug.h header file.

[razvand]

I would give up debug.h all together. And simply import this logging library.

It's simple, easy to use has a lot of stars, and we can improve it for our work (there are a lot of PRs that we can take inspiration from). It's MIT Licensed, compatible with BSD-3-Clause.

We would simply add the two files (log.c and log.h) in the common/folder/. We would include log.h and link against link.c.

[teodutu]

I would give up debug.h all together. And simply import this logging library.

Aggreed. How do you say we should cite / give credit to this library?

[razvand]

Agreed. How do you say we should cite / give credit to this library?

I think you would just add it to the repository and add a comment line in both files to mention the licensing and reference the GitHub link.

[razvand]

@teodutu , I added a test inside the common/ folder and made minor updates to log/ and utils.h. See the commits and see if it's OK with you.

I've also made two minor inline comments.

[razvand]

All OK with me. Merge it, @teodutu .