henry@ginger.sri.com (Henry Pasternack) (07/17/90)
Thank you to everyone who responded to my request for help with my single-board 68000 system. As usual, I have received a lot of helpful suggestions. After some screwing around, I figured out how to use the Sun C compiler to generate ROMable code. It turned out to be fairly easy. I'm using a simple routine in assembly to put the reset vector stuff at the bottom of my ROM (ROM is mapped to zero for the first four reads after reset), followed by a jump to '_main.' I link this in with my compiled C code, and 'ld' it with a starting address corresponding to the bottom of ROM, 0xf00000. Very straightforward. After a terribly frustrating evening during which my board did nothing but halt (I failed to realize that setting the stack pointer to 0x7ffff would result in a misaligned operand trap after a 'jsr') I have succeeded in getting a C-language serial test program running. When I have the time, I'm going to put my mind to writing a loader so I can save wear and tear on my EPROM sockets. -Henry