haydelj / arches-v2 Goto Github PK

Arches is a general-purpose and fast cycle-level hardware simulator.

The name is a pun on being able to simulate various architectures and on Arches National Park, Utah (it being traditional at the University of Utah to name software projects after Utah or Salt Lake City features).

To clone and build the project simply run the following commands:

git clone https://github.com/Haydelj/arches-v2.git
cd arches-v2
mkdir build
cd build
cmake ..

Testing programs on the framework requires the use of a RISC-V Cross-Compiler. Fortunately, many many people have devoted numerous hours to getting a decent RISC-V cross compiler implemented using GCC; this is available here. For our own testing, these are the instructions we followed:

sudo apt update
sudo apt install autoconf automake autotools-dev curl python3 libmpc-dev libmpfr-dev libgmp-dev gawk build-essential bison flex texinfo gperf libtool patchutils bc zlib1g-dev libexpat-dev
git clone https://github.com/riscv/riscv-gnu-toolchain
cd riscv-gnu-toolchain
git submodule update --init --recursive
sudo mkdir -m 777 /opt/riscv
echo -e "export PATH=\"/opt/riscv/bin:$PATH\"" >> ~/.bashrc
source ~/.bashrc
./configure --prefix=/opt/riscv --with-arch=rv64imfa --with-abi=lp64f
make

After these steps are completed, users are able to use riscv64-uknown-elf-gcc to compile C code and riscv64-unknown-elf-g++ to compile C/C++ code.

A key reason we used RISC-V over other research languages (i.e. MIPS) was the ease with which RISC-V can be extended. This allows researchers to use our framework to test novel hardware designs that may rely on custom instructions for drastic performance improvements. It's important to note that this method allows progams using custom instructions to compile; however, it doesn't act as a true cross-compiler, i.e. users will need to use inline ASM to include their custom instructions.

To add custom instructions, we followed the guide available here. Since the time of this guide's writing, there have been a few notable changes to the build tree of the riscv-gnu-toolchain, so we will only note the differences below:

• Use riscv-gnu-toolchain/riscv-binutils/include/opcode/riscv-opc.h instead of riscv-gnu-toolchain/riscv-binutils-gdb/include/opcode/riscv-opc.h.
• Similarly, use riscv-gnu-toolchain/riscv-binutils/opcodes/riscv-opc.c instead of riscv-gnu-toolchain/riscv-binutils-gdb/opcodes/riscv-opc.c. As the original guide notes, after the custom instruction has been added the toolchain will need to be rebuilt. This can be easily accomplished by running the following:

$ cd riscv-gnu-toolchain
$ make clean
$ ./configure --prefix=/opt/riscv --with-arch=rv64imfa --with-abi=lp64f
$ make

After rebuilding, the user should be able to run the cross-compiled programs with their custom instructions on the Arches framework, assuming they have extended the implementation of the RISC-V ISA provided by Arches to contain their custom instruction.

More details about the RISC-V ISA are available by reading the specification, but it's expected that users are at least familiar with RISC-V before they attempt to implement custom instructions.

Follow the coding style in the existing code. Additionally, aim for cleanliness above all else.