fireyfly / sass

SirCmpwn's Assembler

SirCmpwn's Assembler

SirCmpwn's Assembler (sass) is a multiplatform, two-pass assembler written in C#. Presently, it supports z80 out of the box, as well as any user-provided instruction sets. It runs on Windows, Linux and Mac, as well as several other platforms in the form of a library.

Using SASS

On Linux or Mac, make sure that you have Mono installed, and prepend any commands to run Organic with "mono", similar to running Java programs. Note that the default Mono on Ubuntu isn't the full install, remove it and install "mono-complete".

Command Line Usage

Usage: sass.exe [parameters] [input file] [output file]

[output file] is optional, and [input file].bin will be used if it is not specified.

Parameters

--input, --input-file <name>     name of the input assembly file to work on
--output, --output-file <name>   name of the output object file to produce
--instr <instruction-set>        instruction set configuration to use
-h, -?, -help, --help            display this help and exit

Syntax

All examples are given in z80 assembly

SASS's assembly syntax attempts to be as close to other popular syntaxes as possible. Here's some example z80 code that assembles under SASS:

    ld b, 20 + 0x13
label1:
    inc c
    djnz label1

SASS is completely case-insensitive, and whitespace may be used as you please. The exception is that dropping newlines requires you to add \ in their place, like so: "ld a, 1 \ add a, b". However, any number of tabs or spaces in any location is permissible, though "AD D a, b" is invalid, as is "ADDa, b". Labels may use the "label:" form (preferred), or the ":label" form.

Additionally, SASS supports nearly every form that an instruction may be presented in. For instance, each of the following lines of code is acceptable:

cp a, (ix + 10)
cp a, (10 + ix)
cp (ix + 10)
cp (10 + ix)
cp (ix)
cp a, (ix)

Expressions

Anywhere a number is required, you may use an expression. Expressions are evaluated with respect to order of operations, using C precedence. The following operators are available:

* / % + - << >> < <= > >= == != & ^ | && ||

Boolean operators will assemble to "1" if true, or "0" if false.

Relative Addressing

TODO

Local Labels

TODO

Macros

Macros are defined through .macro and may be used in most conditions. To define a macro, use something like this:

.macro example
    ld a, b
.endmacro

This defines a parameterless macro called "example". You needn't indent the contents of the macro; it's done here for clarity. You may also define parameters:

.macro example(foo, bar)
    ld a, foo
    ld b, bar
.endmacro

This is a simple substitution macro. When called (like example(a, b)), 'foo' and 'bar' will be replaced with 'a' and 'b' respectively. Here's a more in-depth example:

.macro example(foo, bar)
    ld a, foo
    ld b, bar
.endmacro
.macro add(a, b)
    a+b
.endmacro
example(1, 2) ; Becomes ld a, 1 \ ld b, 2
ld a, add(2, 3) ; Becomes ld a, 2+3

Pre-Processor Directives

Directives are indicated by a '.' or '#' as the first character, as in "#include <foo.h>".

block [size]: Sets aside size bytes, all set to 0. See fill if you require a value other than 0.

db [value], [value], ...: Inserts any number of 8-bit values into the output.

dw [value], [value], ...: Inserts any number of n-bit values into the output, where n is the number of bits to a word in the target architecture.

echo [message], [message], ...: Echos any number of messages to the console at assembly time. If message is not a string, it will be treated as an expression and echoed as a number.

fill [size], (value): Inserts size number of values into the output. Default value is 0.

org [value]: Sets the internal program counter to value. This does not add to the output.

Compiling from Source

Windows: "msbuild" from the root directory of the project.

Linux/Mac: "xbuild" from the root directory of the project.

Getting Involved

Feel free to fork and submit pull requests with your changes. You'll have good results with small, focused pull requests, rather than broad, sweeping ones. You can also submit issues for bugs or feature requests. You may email me as well at [email protected]. For general z80 assistance, you should join #ti on irc.eversible.com (EFNet).