masmbl

Customizable and extendable simple mips assembler

Simple to change or add instructions.

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Installation

Clone this repository and install masmbl

pip install .

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Running

masmbl <INPUT_MIPS> -d/--data <OUTPUT_DATA> -i/--instruction <OUTPUT_INSTRUCTIONS> Optional arguments:

• [-v | --verbose] verbose
• [-c | --config] yaml file that specifies language. Extend default.yaml in masmbl source folder.
• [-b | --binary] output binary instead of hex data and instructions

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Customize and Extend

Changing the yaml file and using it will allow to create custom instructions whose assembly can be specified.

• Use instruction_input section to specify what format input this new instruction should expect
  • Use special_parsers to specify capture of regex groups that are for special syntax. An example is the lw/sw instructions in default.yaml
• Use instruction_output to specify how to output assembled instruction should look, using the same tokens as in instruction_input
  • Also possible to directly specify number in a slot using bXX... where the X are binary digits 0 and 1

Making new pseudo-instructions is similar

• Use pseudoinstruction_input to specify name and expected format of the input for the pseudo-instruction
• Use pseudoinstruction_output to specify the instruction or instructions the pseudo-instruction should expand into
  • If a pseudo-instruction takes an input named one, to expand it in the output use % signs like so: %one%

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Notes

• This simple assembler expects a .data segment if it exists as the very first segment.
• You must label .text before starting to write code, as it is needed to separate the sections for this simple program
• Most all else is robust to code style, though this assembler does not strictly follow any mips specification closely