HelloWorld on RISC-V

What is the RISC-V

RISC-V is an open standard instruction set architecture (ISA) based on established reduced instruction set computer (RISC) principles. Unlike most other ISA designs, RISC-V is provided under royalty-free open-source licenses. Many companies are offering or have announced RISC-V hardware; open source operating systems with RISC-V support are available, and the instruction set is supported in several popular software toolchains.

Credit: Wikipedia

Prerequirements

Before getting started we need to install toolchain and emulator for RISC-V.

sudo apt install gcc-riscv64-linux-gnu qemu-user

Note: Installation may be different from yours, it's depend on your systems.

The Code

The code below print "Hello World" on console.

.global _start

_start:
	addi a7, zero, 64 # write syscall
	addi a0, zero, 1  # stdout fd
	la a1, helloworld # load string buffer's address
	addi a2, zero, 12 # length of the buffer
	ecall

	addi a7, zero, 93 # exit syscall
	addi a0, zero, 0  # exit status code
	ecall

helloworld:
	.ascii "Hello World\n"

Assemble The Code

Makefile allow us to easily build source file into one easy to use file.

make

Execute The Code

Executable file can be run as below.

./helloworld