The 65816 definition makes it a two-byte instruction, like COP. On
the 6502 it acted like a two-byte instruction, but in practice very
few assemblers treat it that way. Very few humans, for that matter.
So it's now treated as a single byte instruction, with the following
byte encoded as a data value.
This worked, sort of. The problem is that SourceGen will revert to
hex output in certain situations, such as a broken symbolic
reference. There happens to be one in the ZIPPY example, and it's
on a relative branch.
The goal with the segment stuff is to allow cc65 to treat the
source as relocatable code. In that context, a relative branch to
an absolute address doesn't make any sense, so the assembler reports
a range error.
We don't currently have a mechanism that guarantees no references
are broken (and no affordance for finding them), so we can't make
this mode the default yet.
Instead, we continue to use the generic config, but generate the
correct set of lines as comments.
(issue #39)
