DED

June 22, 2020 · View on GitHub

DED

please note that i no longer work with rust and this is not maintained. If anyone has interest in maintaining this crate, feel free to open a github issue.

Elfkit

An elf read and manipulation library in pure Rust (written from scratch, no bfd, no gnu code, no license infections), intended to be used in binary manipulation utils such as strip, chrpath, objcopy and ld. The end goal is to build a well designed library that facilitates all sorts of binary manipulation magic.

elfkit can now link elfkit, so it's reasonably complete for x86_64. But it's definitely not stable yet and might produce incorrect code.

Using the linker

The quickest way to use elfkit with Rust is with korhal/stasis.

You can also either build from source or download binaries. GCC does not have an option to use a foreign linker, so we need to pretend we're ld.gold, like so:

curl -L https://github.com/aep/elfkit/releases/download/0.0.4/elfkit-0.0.4.tar.xz | tar xvjf -
export PATH="$PWD/elfkit-0.0.4/:$PATH"
musl-gcc -fuse-ld=gold main.c

For using elfkit for compiling Rust code, add the following to ~/.cargo/config:

[target.x86_64-unknown-linux-musl]
rustflags = [
    "-C", "link-arg=-fuse-ld=gold",
    "-C", "link-arg=-Wl,-dynamic-linker,/usr/local/musl/lib/libc.so",
]

When compiling from source, create the ld.gold symlink manually:

cargo build --release --bin ld
ln -s "$PWD/target/release/ld" /usr/local/bin/ld.gold

Other binutils

readelf: screenshot

implementation status

binutils

type	status	gnu compatible
ldd	done	no
readelf	done	no
ld	wip	wip
objdump	-	-
ar	-	-
as	-	-
nm	-	-
strip	-	-

section parsers

type	read	write
symbols	done	done
strtab	done	done
relocations	done	done
dynamic	done	done
note	-	-
gnu_hash	-	-
hash	-	mvp
versym	-	-
verneed	-	-

architectures

abi	parser	linker
x86_64	done	wip
mips32r2 o32	done
arm eabi	done

modular linker toolkit

Loader: loads elf objects from disk
Linker: produces a link graph of sections from a loader
Collector: bakes multiple sections into a single object
Relocator: applies relocations to a combined object

alternatives

goblin mach-o and archive support, no-std support, very low level
elf most popular, most generic use case, no writing, no section parsing
xmas-elf zero alloc (good for writing an OS), read only