Build qemu as a library

unicorn_but_worse.sh

#!/bin/sh

set -e

[ -z "$1" ] && echo "Usage: $0 <target>" && exit 1

case "$(uname)" in
  Linux)
    ncpu="$(nproc)"
    ;;
  Darwin)
    ncpu="$(sysctl -n hw.physicalcpu)"
    ;;
esac

flags="$(./configure --help | perl -ne 'print if s/^  ([a-z][\w-]*) .*/\1/' | tail -n +2 | awk '{print "--disable-"$1}' ORS=' ')"

${2:-.}/configure --extra-cflags=-fPIC --target-list=$1 --disable-slirp $flags

make clean >/dev/null

file=$(mktemp)

make -n 2>/dev/null >$file

cmdline="$(cat $file | perl -ne "print if s/.*LINK.*$1.*&&  //" | perl -ne 's/ -o qemu-system-[a-z]+/ -shared -o libqemu.so/; print')"
vl="$(cat $file | perl -ne 'print if s/.*CC.*vl.o.*&& //' | head -n 1)"

# Build everything as usual
make "-j$ncpu" >/dev/null

# Build vl.c but better
$vl -D"main=__definetly_not_main_lmao__"

# Build a shared library, without vl.o and otherwise *exactly* the same
# flags.
cd $1

$cmdline

echo "$(echo "$vl" | grep -E -o '(-I|-f|-W|-m|-p)[^ ]+' | tr '\n' ' ')" \
  "$(echo "$cmdline" | grep -E -o '(-Wl|-l|-L)[a-z0-9-]+ ' | sed '/-labels/d' | sed '/-limits/d' | tr '\n' ' ')"

Usage.md

Place file into qemu root directory Do cd path/to/qemu && ./name_of_file name_of_target (i.e. x86_64-softmmu) Library is at /path/to/qemu/x86_64-softmmu/libqemu.so You might need to compile vl.c and link with it in your final binary, just do something like this:

#define main __definetly_not_main
#include "/path/to/qemu/vl.c"
#undef main

int main() {
  // Whatver you want to do with qemu
}

I'm still getting ERROR: Unknown target name 'x86_64-softmmu'

Please note that the cmdline on Line 26 of the script is outdated and incompatible with recent versions of the QEMU source. It currently defines to an empty string.

Please note that the cmdline on Line 26 of the script is outdated and incompatible with recent versions of the QEMU source. It currently defines to an empty string.

Could you suggest us any changes in the script that would work with qemu-9.0.0 (so that the vl.o file could be compiled)?

Please note that the cmdline on Line 26 of the script is outdated and incompatible with recent versions of the QEMU source. It currently defines to an empty string.

Could you suggest us any changes in the script that would work with qemu-9.0.0 (so that the vl.o file could be compiled)?

Hello. I cannot. This is unfortunately far from my current understanding of shared libraries .