Embedded Programming with Android: Bringing Up an Android System from Scratch

6. Using the C Library

In the previous chapter, we learned how to use C language in the bare metal programming environment. However, a few things are still missing from our knowledge base. One of the fundamental topics we haven’t covered yet is use of the standard C library functions, such as printf, scanf, malloc, and so on. Usually, the C library has dependencies on operating system (OS) services. The operating system provides these services through system calls. Because there is not an operating system in a bare metal environment, we have to implement these system calls ourselves. That is the major topic discussed in this chapter.

C Library Variants

When a C library is used in a bare metal environment, it usually comes with several variants, ...