Z80 Assembler

This is a Zilog Z80 assembler.

I've already written a Z80 assembler in Python which is available in my z80 repository. The difference is that zasm is a 2-pass asm whereas the python one passed the source several times and is significantly slower.

Syntax

; Comment (until newline)

label:
  ld hl, [msg + 2]           ; Indirect addressing is using [square brackets].
                             ;   This is different from most Z80 assemblers
                             ;   which use (parentheses).
                             ;   Expressions (including labels and characters)
                             ;   are allowed.
  jp $                       ; $ = current address
  RET NZ                     ; Instructions, conditions and directives are
                             ;   case-insensitive.

; Directives
include "another/file.s"     ; Include another source
incbin "binary/file.bin"     ; Include binary data
org 0x8000                   ; Assume the code is loaded at address 0x8000
db "Hello, World!", 10, 0    ; Emit bytes
dw 'a'                       ; Emit words (this example will result in
                             ;   0x61 0x00 being emitted)
ds 100, 45                   ; Emit 100 bytes filled with value 45
def IDENTIFIER, 1            ; Define UART_PORT identifier as number 1

Literals

Number formats allowed are:

• decimal: 97,
• hexadecimal: 0x61 (however, 61h is currently unsupported),
• octal: 0141,
• and character-based: 'a'.

Strings are delimited by ".

CLI arguments

-e, --export-labels

Save labels and their corresponding addresses to a file.

-l, --import-labels

Import labels from a file.

-v, --verbosity

Make the output verbose with level 1 or 2.

-o, --output

Emit the resulting binary into a file.

-t, --tap

Save the code as a tape image (TAP format, e.g. for use in ZX Spectrum emulators).

TODO

• Importing labels from multiple files