50 lines
2.2 KiB
Markdown
50 lines
2.2 KiB
Markdown
# README
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### Overview
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This project is a custom emulator/VM, along with tooling such as an assembler, disassembler, and integrated debugger. It was originally written as a challenge for a CTF run by my school's computer security club. It has been refactored and reorganized. In the future, I _may_ reuse this challenge and modify it, mainly so that it cannot be unintentionally autosolved by the angr framework (as it was in its original form).
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For documentation on the assembly language and architecture, consult the relevant file(s) in `doc/`.
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* TODO: document assembly language
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### Documentation
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See files in `/doc` for my design process, VM specs, lessons learned, and other stuff.
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### Build
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Build "normal" competition/prod image (default):
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`$ make`
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Build trace image (integrates debugger into the build):
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`$ make trace`
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* Note: in-between making the normal and trace images, one should run `make cleano` to remove previous object files, since they'll differ between normal and trace builds
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Build disassembler:
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`$ make disass`
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Build VM ROM:
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`$ make rom`
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* Note: if one updates the ROM assembly in rom.asm, they'll need to manually rebuild the ROM.
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The assembler, `ass.sh`, is already good to go (as good as a bad shell-scripted assembler can be at least).
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### Run
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`$ ./bin/hard`
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or
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`$ ./bin/hard-trace`
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depending on which version you wish to run.
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### Tooling
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To use the debugger, simply build and run the trace image, as the binary will automatically place you in the debugger to start.
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The assembler, `ass.sh`, can be used to create a binary ROM image given an assembly language file (file extension `.asm`) and an optional zero page initialization file (`zeropage.incbin` in the challenge's case). The latter if present, is used to initialize the first 256 bytes of ROM to some hardcoded state.
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The disassembler, `disass`, is located in the `bin/` directory upon being made.
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For usage information for both tools, run them with no arguments.
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