I would like to know of references that discuss the process of uploading code onto an Arduino board. I have read this reference on hacking the Arduino and an outline of the build process. I also found this segment on creating Arduino libraries informative.

Overall I am interested in tracing through an upload process to learn more detail about how the programming works. I would like to understand which C-libraries are used. I would like to understand how the code is uploaded onto the Arduino. One example that I would like to see is an direct upload of C or C++ code without using the IDE gui. I want to see kind of the "bare-minimum" necessary for programming the Arduino (in C/C++). I would ideally like to read about something like this which makes use of the Arduino libraries.

Looking forward to hearing back responses, and being a part of this community. Any references and comments appreciated.