# Calling convention
## boot0
I'm not sticking to any particular calling convention for boot0, since we have to golf to fit in
440 bytes. Whatever's most convenient.

## boot1
- Arguments: ax, cx, dx, stack
- Return value: ax, cf for booleans
- ax may be clobbered. All other registers are preserved
- Callee cleanup (i.e. the function pops stack arguments when returning)