# Introduction

This chapter shows you how to create cross platform tools.

If for some reason you have to stop and come back later, remember to use the `su - clfs` command, and it will setup the build environment that you left.

## Common Notes

Before issuing the build instructions for a package, the package should be unpacked, and a `cd` into the created directory should be performed.

Several of the packages are patched before compilation, but only when the patch is needed to circumvent a problem. A patch is often needed in both this and the next chapters, but sometimes in only one or the other. Therefore, do not be concerned if instructions for a downloaded patch seem to be missing. Warning messages about offset or fuzz may also be encountered when applying a patch. Do not worry about these warnings, as the patch was still successfully applied.

During the compilation of most packages, there will be several warnings that scroll by on the screen. These are normal and can safely be ignored. These warnings are as they appear—warnings about deprecated, but not invalid, use of the C or C++ syntax. C standards change fairly often, and some packages still use the older standard. This is not a problem, but does prompt the warning.

After installing each package, both in this and the next chapters, delete its source and build directories, unless specifically instructed otherwise. Deleting the sources prevents mis-configuration when the same package is reinstalled later.