may be worth running the slightly bigger 'Heritage' /bin/sh with SYS5 type
features instead
- date gives bogus results, probably some sizing issues
-- signal handling needs further testing
+- signal handling needs further testing (disabled on IRQ path currently)
- copy exception/trap frames onto user stack along with trap identifiers
so we can support stuff like CP/M68K emulators.
-- pre-emption needs more testing
+- pre-emption needs more testing (also disabled on IRQ path currently)
- support multiple IRQ sources and IRQ priority nesting when appropriate
- enable IRQ during swap on context switch
- optimize swap out/in. With bigger amounts of RAM we want to be smarter