Debugging an embedded system

When you're developing embedded systems under some operating systems, you often need to use a hardware debugger, a physical device that connects to target hardware via a JTAG (Joint Test Action Group) interface. This is necessary for development of drivers, and possibly user applications, because they're linked into the same memory space as the kernel. If a driver or application crashes, the kernel and system may crash as a result. This makes using software debuggers difficult, because they depend on a running system.

Debugging target systems with Neutrino is different because its architecture is significantly different from other embeddable realtime operating systems:

• All Neutrino applications (including drivers) run in their own memory-protected virtual address space. This has the advantage that the software is more reliable and fault tolerant. However, conventional hardware debuggers rely on decoding physical memory addresses, making them incompatible with debugging user applications based in a virtual memory environment.
• Neutrino lets you develop multithreaded applications, which hardware debuggers generally don't support.

Under Neutrino, you typically use:

• a hardware debugger for the IPL and startup
• a software debugger for the rest of the software

In other words, you rarely have to use a JTAG hardware debugger, especially if you're using one of our board support packages.