4. Host Development Platform

Embedded Linux's compelling advantage over other Embedded OS's is that your development host and target are the same. While you could theoretically develop your embedded Linux target system software on any host OS, Linux is the only sensible choice. Even Cygwin/UWIN is likely to waste more of your time.

4.1 PowerPC

Using a PowerPC based development development host platform makes life easier, since the same binaries will run on your host and target. However, if your choice of host platform is restricted to non-PowerPC, cross compiling adds some minor inconvenience, primarily in finding or building your own toolset.

You can take binaries from a standard PowerPC-based G4 Macintosh Linux distribution and run them unmodified on a PowerPC embedded system provided:

• The binaries are dynamically linked.
• You use the modified dynamic runtime glibc C library, but compiled with -mhard-float.
• You include the floating point math emulator in the kernel for processors such as the 8xx series that lack a real floating point unit.

Note that for floating-point intensive applications this will invoke a performance penalty over re-compiling all the binaries and libraries; but recompiling is what you're trying to avoid, right?

Also note that standard Macintosh binaries won't work with the runtime library in the Hard Hat distribution on 8xx processors, because they've been compiled with -msoft-float to give optimum performance. In this case just use the equivalent Hard Hat binaries instead.

4.2 x86

Doing it this way is slightly more painful, but it's what most people use.