Early data sheets listed BRK as one byte, but RTI after a BRK skips
the following byte, effectively making BRK a 2-byte instruction.
Sometimes, such as when diassembling Apple /// SOS code, it's handy
to treat it that way explicitly.
This change makes two-byte BRKs optional, controlled by a checkbox
in the project settings. In the system definitions it defaults to
true for Apple ///, false for all others.
ACME doesn't allow BRK to have an arg, and cc65 only allows it for
65816 code (?), so it's emitted as a hex blob for those assemblers.
Anyone wishing to target those assemblers should stick to 1-byte mode.
Extension scripts have to switch between formatting one byte of
inline data and formatting an instruction with a one-byte operand.
A helper function has been added to the plugin Util class.
To get some regression test coverage, 2022-extension-scripts has
been configured to use two-byte BRK.
Also, added/corrected some SOS constants.
See also issue #44.
Instead of providing no-op CheckJsr/CheckJsl, plugins now declare
which calls they support by defining interfaces on the plugin class.
I added a CheckBrk call for code like Apple /// SOS calls, which
use BRK as an OS call mechanism. The formatting doesn't work quite
right yet because I've been treating BRK as a two-byte instruction.
Hardly anything else does, and I think it's time I stopped (but not
in this commit).
Note: THIS BREAKS ALL PLUGINS that use the inline JSR/JSL feature,
which is pretty much all of them.
The instruction operand editor and data operand editor are very
different, but there's no need to impose that distinction on the
user. They want to edit the operand either way. We now provide a
single "edit operand" menu item, and open the appropriate dialog
based on what they have selected.
This uses Ctrl+O as the keyboard shortcut, stealing it from
File > Open.
(issue #11)
If set, the first word of the file is used to set the load address.
The initial code entry hint is placed at offset +000002 instead of
the start of the file.
Set it to true for the C64 system definition.
(issue #23)
