Radiance

A two-pass assembler, linker and emulator for a 32-bit ARM-like assembly language, modeled on the GNU toolchain. Built from scratch in C++ for the System Software course at ETF Belgrade (2022/2023).

Tools

Tool	What it does
assembler	Two-pass assembler with a Flex/Bison front end. Handles sections, .global/.extern, .word, .skip, .equ expressions that are resolved once their symbols are known, and literal pools for constants that don't fit in an instruction. Emits relocatable object files in an ELF32-style format
linker	Merges object files, resolves symbols and applies relocations. -relocatable links into another object file, -hex produces a memory image, and -place=section@address pins sections to addresses
emulator	Runs the memory image on an emulated CPU with control and status registers, a timer and a memory-mapped terminal. Interrupts are prioritized (software and bad instruction first, then timer, then terminal) and can be masked individually
readobj	Dumps the sections, symbols and relocations of an object file

Example

.equ init_sp, 0xFFFFFF00
.global my_data
.section text
    ld $init_sp, %sp
    ld $handler, %r1
    csrwr %r1, %handler
    ld my_data, %r1
    halt
my_data:
    .word 5
.end

assembler -o main.o main.s
assembler -o handler.o handler.s
linker -hex -o program.hex -place=text@0x40000000 main.o handler.o
emulator program.hex

Building

Requires g++, make, flex and bison on Linux.

./build.sh    # generates the lexer and parser, then builds and installs the four tools to /usr/bin
./clean.sh

tests/ has small programs and scripts, and 01-ss-2022-2023-projekat-odbrana-testovi/ has the course's acceptance tests at three levels (nivo-a, nivo-b, nivo-c).