39 lines
1.5 KiB
Markdown
39 lines
1.5 KiB
Markdown
# emul
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This is an emulator for a virtual machine that is suitable for running Collapse
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OS. The goal of this machine is not to emulate real hardware, but rather to
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serve as a development platform. What we do here is we emulate the z80 part,
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the 64K memory space and then hook some fake I/Os to stdin, stdout and a small
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storage device that is suitable for Collapse OS's filesystem to run on.
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Through that, it becomes easier to develop userspace applications for Collapse
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OS.
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We don't try to emulate real hardware to ease the development of device drivers
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because so far, I don't see the advantage of emulation versus running code on
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the real thing.
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## Bootstrapped binary
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The file `zasm/zasm.bin` is a compiled binary for `apps/zasm/glue.asm`. It is
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used to bootstrap the assembling process so that no assembler other than zasm
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is required to build Collapse OS.
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This binary is fed to libz80 to produce the `zasm/zasm` "modern" binary and
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once you have that, you can recreate `zasm/zasm.bin`.
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This is why it's included as a binary in the repo, but yes, it's redundant with
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the source code.
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## Usage
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First, make sure that the `libz80` git submodule is checked out. If not, run
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`git submodule init && git submodule update`.
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The Makefile in this folder has multiple targets that all use libz80 as its
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core. For example, `make shell` will build `./shell`, a vanilla Collapse OS
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shell. `make zasm` will build a `./zasm` executable, and so on.
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See documentation is corresponding source files for usage documentation of
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each target.
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