Is the official assembler for the 8-Bit microprocessor Monty08 that converts M08-Assembly into executable binaries for the Monty08. This project now consists of a parser for the M08-Assembly language and an assembler for generating the needed binaries that can be then uploaded onto the main memory of the microprocessor. Looking into the future I plan to also implement a parser for a dedicated high level language like C/C++ with and additional optimizer.
- Custom M08-Assembly language inspired by the intel x86 asm
- Dynamic Data, BSS and Text sections that can be arranged in their order and alignment
- Virtual instructions emulated on the CPU that expand the ISA of the Monty08
- Adjustable output and code size
- verbose syntax checkup of source file
- Logisim hex output so the program can be loaded into Logisim components
- Comments
This project uses Premake to ensure a platform independent usage. Execute the Setup-Script inside the Scripts-Folder to generate the project for your platform.
Either you are building this project yourself or taking the release - binaries, you just open up a terminal and use the additional command line arguments to control the behaviour of this application.
Use wrench --help to list the valid arguments:
Usage: wrench source_file.asm [arg_name...]
Possible arguments:
-o, --output: An absolut or relative path to the file that gets outputted.
-s, --size: Size of the compiled binary program.
-c, --code: Size of the text section (code).
-l, --logisim: Generates an additional hex file that can directly be loaded by Logisim.
-m, --nomc: Uses the arithmetic instructions for the non-microcode ALU.
The assembler then parses the given source file and assembles it into a .m08 file, as defined using the -o argument.
As already mentioned the Assembly language is highly inspired by existing languages and covers the most important elements of them. The following example shows all the features contained in the M08-Language:
#define register0 r0
#align text 8
// Map data to heap memory
org .data 5800h
section .data
// States of port
_digits:
db 11111110b 11111101b 11111011b 11110111b 11101111b 11011111b 10111111b 01111111b
section .bss
_data:
resb 10h
section .text
// Init and counter
ldav 7
xchop
one
portwrt p0
portwrt p1
_loop:
modr 04h
ldahpi r0
portwrt p0
movar r0
cmp
jmpne [loop]
// Reset memory pointer
ldrv r0 0
jmp [loop]
Instructions starting with a # indicate a preprocessor directive that gets parsed before the main parsing cycle and contain meta-information about the program itself.
- All numeric values including the command line arguments can be represented in different number-systems using different postfixes: 'o' = octal, 'h' = hex, 'b' = binary, 'q' = quad, 'd' or blank = decimal.
- Sections are case-insensitive, the dot is optional, means:
.text = .Text = TEXT = text. - Available registers (case-insensitive):
r0andr1 - Available ports (case-insensitive):
p0andp1 - labels referenced in instruction operand are enclosed by
[], means jumping to a label looks like this:jmp [sample_label]
Syntax: #align [section] [numeric_multiple]
Description: Aligns the given section to start at a multiple of numeric_multiple bytes.
Syntax: #define [symbol] [alias]
Description: Creates an alias that gets then replaced by symbol during the assembly stage.
Syntax: org [section] [numeric_offset]
Description: Defines the offset at which a specific section begins. Offset = 0 means the section starts at address 0 of the program. Be aware of possible conflicts between two or more sections that collide.
Syntax: _[label]:
Description: Creates a symbolic label representing the address of the next Instruction/Definebyte/Reservebyte in the context of the assembled program.
Syntax: section [section]
Description: Introduces one of the three sections: [.text/.bss/.data]. The program stays in the same section until a new section is introduced.
BSS: uninitialized data (only resb is valid in this section), DATA: data initializied with a non zero value (only db is valid in this section), TEXT: code of the program
Syntax: db [bytestream]
Example: db 16h 44o 12, db "string"
Description: Places the given bytestream directly into the program as raw data that can then be later accessed by the microprocessor.
Syntax: resb [numeric_size]
Description: Allocates space of size numeric_size inside the programs memory space that can then be written to. A label should point to that memory region.
Syntax: [instruction] [param0] [param1] [operand0] [operand1]
Description: A single instruction as part of the code consisting of a instruction defined by the Monty08-ISA and additional arguments that are optional. Read the ISA for additional information on all available instructions and their parameters.