| Rev |
Log message |
Author |
Age |
Path |
| 34 |
Bunches of changes, although very little changed with the core itself.
Regarding the core, some bugs were fixed within zipcpu.v (the CPU part of the
core), so that the debugger can change the program counter. The debugger
can now halt the CPU and then view, examine, and modify registers to include
the program counter, although live changes to the CC register have not been
tested.
There was also a bug in the stall handling of the wishbone bus delay line. This
has now been fixed.
Moving outwards to the system, some parameters have been added to zipsystem
to make it more configurable for whatever environment you might wish to place
it within. Other minor clean ups have taken place, mostly to the internal
documentation.
Lots of changes, though, to the assembler. The big one is the implementation
of #define macros, C style. Several buggy macros were in sys.i. These have
been fixed. The Makefile has been adjusted so that the build of test.S, which
depends upon sys.i, is now properly dependent upon sys.i for make purposes.
Further, not only will zpp, the assembler preprocessor, handle #define macros,
it will also recursive #defines. The assembler expression evaluator has also
been updated to properly handle both operator precedence, as well as modulo
arithmetic.
The master system test file, test.S, found in the sw/zasm directory has been
updated to reflect these new capabilities. (I really need to move it to the
bench/asm directory, so you may expect that change sometime later.) |
dgisselq |
3395d 15h |
/zipcpu/trunk/sw/zasm/zasm.l |
| 26 |
Added signed and unsigned multiply opcodes to the assembler.
An opcode was added for a 'negate' instruction. This is a derived instruction
that turns into two instructions. Neg RX becomes an XOR -1,Rx followed by an
Add 1,Rx command. (Move 1+Rx,Rx would've stalled the bus by one cycle.)
Instructions now keep track of the source linenumber (but not yet filename)
where they were issued. That way, upon an error in linking at the end, the
instruction can be referenced by the proper line number. (Filenames are still
not implemented, hence include files may reference the line number of the
include file with no proper indication of that ... yet).
The OBJFILE intrface now supports a clos() function. This allows the
assembler to close and delete the object file for those cases where the
preprocessor encounters an error.
The master test file, sw/test.S, was adjuted as follows: many of the tests
within it can be separated by #ifdef lines. Hence, if you only wish to test
whether or not CARRY works, undefine all of the other ifdefs but leave the
CARRY_TEST defined. (PUSH_TEST, a test of the PUSH(RX,SP) macro, still doesn't
work because the assembler still doesn't implement macros. This is still a
coming feature.)
The master test file now has tests for the break function, as well as for the
new trap CC bit and the new multiply signed and unsigned instructions in the
ALU.
Many error conditions were added to the assembler preprocessor. Now, if an
EOF is encountered in anything but the INITIAL state (not within a macro),
an error will be created. Likewise, any unrecognized preprocessor directive
will create an error.
The lexical analyzer now supports character values, such as 'a' or '\n' using
a C-type syntax. (Tri-graphs are not supported.) It also supports such
extended syntax as '$GPG'. (Hmm ... wonder why I needed that?)
The lexical analyzer now recognizes and properly supports #line preprocessor
output statements. Theselines are then used to track what source line errors
occurr at.
Operand precedence has been adjusted, so the assembler should be able to
properly handle things like 5+3*8 and get the same number answer as 3*8+5.
(This has been implemented, although not thoroughly tested.)
Upon completion of any preprocessing file, the assembler now checks the status
of the preprocessor as returned by its exit code. Anything other than a zero
status will cause the assembler to delete the resulting object code file it is
building and exit with an error.
The assembler also supports the '-d' command line flag to turn on debugging in
the yacc processor (setting yydebug). It'll produce a lot of debugging output,
but it just might help to figure out what 'syntax error' is actually taking
place. |
dgisselq |
3399d 08h |
/zipcpu/trunk/sw/zasm/zasm.l |
| 16 |
The assembler now supports:
1. Multiple data elements on a line. These are lines like:
WORD 5,8,4,1
which place the words 5, 8, 4, and 1 directly into the object code to be
referenced as data. Prior to this release, these lines would assemble
properly but only place '5' as a data element into the object code.
2. The '-E' preprocessor only directive is now supported to produce output
from the preprocessor and see what is (or is not) happening there.
3. The preprocessor now validly places "#line" comments into the file, which
the assembler picks up and uses in it's error codes. These help identify
where errors took place.
4. Zasm now looks for the preprocessor (zpp) in the same directory zasm was
run from, using the same directory prefix as zasm, whenever zasm is given such
a directory prefix.
And ... perhaps other things I've forgotten about. |
dgisselq |
3406d 15h |
/zipcpu/trunk/sw/zasm/zasm.l |
| 13 |
Finally! The beginnings of the new assembler. It's not really polished yet,
and it is quite clunky, but it works!! (Lots of bugs and features left to
fix/implement: #include, #define macro(), #line tracking through the
preprocessor, a means of finding include files (and the preprocessor!) and
more. But, as a beginning, the basics are functinoal. |
dgisselq |
3408d 22h |
/zipcpu/trunk/sw/zasm/zasm.l |
