While I was ideally surfing around this week I came across
http://ultibo.org, a programming environment for developing bare metal applications for the Raspberry Pi.
I've been translating my C/C++ 65C816 emulation code into Pascal and trying it on a Raspberry Pi2 (900Mhz quad-core ARM Cortex A7 + GPU).
At the moment I have a simple counting loop running with lots of debug output scrolling up my old 38" TV. The Pi has loads of memory so my emulation has the full 24MB of 65C816 address space available. The startup code loads the memory from an S28 file when the Pi boots.
When I have more the opcodes implemented and tested I want to implement an 800x600 memory mapped graphical display in one of the banks, until then the character display works well.
The code framework supports threads so I can add background processing for a USB keyboard and mouse later.