{"id":71,"date":"2024-09-27T08:30:23","date_gmt":"2024-09-27T08:30:23","guid":{"rendered":"https:\/\/haco.club\/?p=71"},"modified":"2024-09-27T08:30:23","modified_gmt":"2024-09-27T08:30:23","slug":"risc-v-simulation-with-qemu","status":"publish","type":"post","link":"https:\/\/haco.club\/?p=71","title":{"rendered":"RISC-V simulation with Qemu"},"content":{"rendered":"\n
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https:\/\/medium.com\/@e1d1\/risc-v-simulation-with-qemu-61ea8f2d8f4b<\/a><\/p>\n<\/blockquote>\n\n\n\n

Installation of Qemu<\/h2>\n\n\n\n

On the Qemu website, you can find a lot of information on how to get it running. But for the specific purpose of this tutorial, a few important extra steps are needed.<\/p>\n\n\n\n

In order to use the user mode simulation, your host system must be Linux. I recommend installing from source as described on this\u00a0site<\/a>\u00a0using configure with\u00a0–target-list= riscv32-linux-user,riscv64-linux-user, riscv32-softmmu,riscv64-softmmu\u00a0as a configuration. I assume you have a RV toolchain running, if not,\u00a0here<\/a> is how.<\/p>\n\n\n\n

User-Mode<\/h2>\n\n\n\n

The simplest way of getting an environment for RV programming is the user mode of Qemu. You cross compile your program as if it were on an RV system running Linux. Then you run your program with Qemu user mode.<\/p>\n\n\n\n

To illustrate, I give a short example of compiling and running a C program. I assume you have a running set up for Linux.<\/p>\n\n\n\n

echo -e '#include <stdio.h>\\nint main(){\\n printf(\"hi\\\\n\");\\n return 0;\\n}' > hi.c\nriscv64-unknown-elf-gcc -o hi hi.c \nqemu-riscv64-static hi<\/code><\/pre>\n\n\n\n
System-Mode<\/h2>\n\n\n\n
The system mode of Qemu lets you simulate a complete operating system. For example, you can run Linux inside this simulation. You can change (e.b. log in) to this guest system, install all tools you need and run your own RV programs. However, depending on the system chosen, you might need to cross compile your program on your host and transfer your program to the simulated guest system.<\/p>\n\n\n\n
To make these steps a bit easier, I will show you how to get a Linux system up for an RV32 using Buildroot<\/a> and for an RV64 using Debian<\/a>.<\/p>\n\n\n\n
RV32: Linux using Buildroot<\/h2>\n\n\n\n
This is very easy to achieve. Get Buildroot and build:<\/p>\n\n\n\n
git clone https:\/\/git.buildroot.net\/buildroot\nmake qemu_riscv32_virt_defconfig\nmake<\/code><\/pre>\n\n\n\n
Note, you can customize your Buildroot system before\u00a0make<\/code>\u00a0with\u00a0make menuconfig<\/code>, for example, to install\u00a0gdbserver<\/code>. Then run Qemu with<\/p>\n\n\n\n
qemu-system-riscv32 \\\n   -M virt \\\n   -bios output\/images\/fw_jump.elf \\\n   -kernel output\/images\/Image \\\n   -append \"root=\/dev\/vda ro\" \\\n   -drive file=output\/images\/rootfs.ext2,format=raw,id=hd0 \\\n   -device virtio-blk-device,drive=hd0 \\\n   -netdev user,id=net0 -device virtio-net-device,netdev=net0<\/code><\/pre>\n\n\n\n
These options do the following:<\/p>\n\n\n\n