README.md

nemu-zig

My nemu (NJU EMUlator) implement in Zig. Now supports riscv32im ISA.

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nemu-zig is developed with the master branch version of Zig. The latest tested zig version is 0.13.0-dev.46+3648d7df1.

How To Run

First make sure zig is in your $PATH. (The pre-built binary of Zig can be downloaded from here)

Build And Run NEMU

Run built-in image:

zig build run

Run your own image:

zig build run -- /path/to/image.bin

Run with disasm:

llvm needs to be installed before running disasm.

zig build -DITRACE run

Run with difftest:

nemu support comparing running result with spike while simulating riscv32.

make difftest IMG=/path/to/image.bin

Run Unit Tests

Zig provides zig test which can be used to ensure behavior meets expectations.

Unit tests are defined in src/test.zig. But now only expr test was supported.

zig build test

Possible problems

library 'LLVM' not found

This problem may occur when running nemu-zig with disasm on Debian-based systems.

-> % zig build -DITRACE                                                         
install                                                          
└─ install nemu-zig                                              
   └─ zig build-exe nemu-zig Debug native failure                                                                                 
error: error: unable to find Dynamic system library 'LLVM' using strategy 'paths_first'. searched paths:

Solution:

// build.zig

// change this line
exe.linkSystemLibrary("LLVM");
// to (modified "16" to your llvm version)
exe.linkSystemLibrary("LLVM-16");

'llvm-c/*.h' file not found

This problem may occur when running nemu-zig with disasm on Debian-based systems.

nemu/lib/llvm_slim.h:1:10: error: 'llvm-c/Disassembler.h' file not found
#include <llvm-c/Disassembler.h>
         ^~~~~~~~~~~~~~~~~~~~~~~~

Solution:

# Modified "16" to your llvm version
sudo ln -s /usr/include/llvm-c-16/llvm-c/ /usr/include/llvm-c
sudo ln -s /usr/include/llvm-16/llvm /usr/include/llvm