Rasm

Rasm is a simple but powerful RISC-V (RV64I) assembler that aims to make the syntax to be more like C, and it's written in Nelua.

Syntax

Rasm's syntax is just like the RV64 standard, except for these changes:

• Load a string globally.
  String = "Hello!"
String is now a label!
• Prefixing a label with '%' while refering, gets the length of the label. li a0,%String
• Calling a function.
  

function:
...
ret

function(1,String)

This is the equivalent to:

li a0,1
la a1,String
call function

(Also the load and store instructions no longer have the special syntax.
ld rd,imm(r1) -> ld rd,r1,imm)

Usage

Usage: rasm [d][s][o a.out] filein.asm
'-' are optional.

• Options
  • d: dump compiled raw binary to 'dump.bin'
  • s: add section name
  • o a.out: outfile for compiled code

Instruction Set

• RV64I Base
  
• Pseudoinstruction
  
• Integer Multiplication and Division Extension
  
• Single-Precision Floating-Point Extension
  
• Double-Precision Floating-Point
  
• Compressed Instructions

Setup & Install

Install Qemu User Static

You will need Qemu User Static run to the executable.

Debian/Ubuntu (apt)

apt update
apt install qemu-user-static

Void Linux (xbps)

xbps-install -Su qemu-user-static

Building with Nelua:

1. Install Nelua
2. Clone Rasm git clone https://github.com/Doubleshotgun/Rasm
3. Compile

cd Rasm
make

Building with GCC/Clang:

1. Clone Rasm git clone https://github.com/Doubleshotgun/Rasm
2. Compile

cd Rasm
make CC

Installing

The executable is automatically install at /usr/local/bin/

Example

• example.asm

exit = 93

_start:
	li a7,exit
  li a0,69
  ecall

• bash

rasm example.asm
qemu-riscv64-static a.out
echo $?

This program returns exit code of 69, echo $? prints the exit code of the last program

See the example folder for more.

Todo

• Rework the "Syntax system".
• Rework the syntax of "call" and "ecall".
• Better error message.
• Add hex notation.
• Add array, struct and vectors.

• Make standard library.
  • syscall
  • io
  • string
  • time
  • math
  • fb (frame buffer device)

• Tested on Window.