In C, is there a good way to define length first, Pascal-style strings as constants, so they can be placed in ROM? (I\'m working with a small embedded system with a non-GCC
You can still use a const char * literal and an escape sequence as its first character that indicates the length:
const char *
const char *pascal_string = "\x03foo";
It will still be null-terminated, but that probably doesn't matter.