/* ** The next line is a guess */ typedef unsigned long UINT32;

It looks like it is also in types/vxTypesOld.h, and I bet others.

I'm using the default start address of 0x00008000.

Just watching the vxWorks link step, I see that they place the text segment at 0x1000, that is probably the first thing I would try. You can also type make vxWorks in the BoardSupport\VxWorks\IXP1200EB directory and watch for other compiler/linker options being passed into the process of making vxWorks. It looks like they change the entry point to sysInit, but I can't image the actual name of the entry point is important. I also wonder if the boot loader assumes anytype of compression and/or checksums. I thought there was a checksum in the a.out header (?) and I don't think the vxWorks image I have is compressed (I can look at its symbols...) erik