arm_now is a qemu powered tool that allows instant setup of VM for reversing/running binaries built for different CPU architectures.

arm_now instantly deploys and starts a virtual machine when needed, I mainly use this for security purpose (reverse/exploit/fuzzing).

# pip3 install https://github.com/nongiach/arm_now/archive/master.zip

$ mkdir test
$ cd test
$ arm_now start armv5-eabi --clean
Welcome to Buildroot
buildroot login: root
# uname -m
armv7l

$ arm_now start microblazeel --clean
Welcome to Buildroot
buildroot login: root
# uname -m
microblaze

Use the --sync option, you have to type the command save before exiting the guest. This might not work if there are a lot of files in the current directory.

$ ls
a_file_created_on_the_host
$ arm_now start armv5-eabi --clean --sync
Welcome to Buildroot
buildroot login: root
# ls
a_file_created_on_the_host
# touch a_file_create_on_the_guest
# ls
a_file_created_on_the_host a_file_create_on_the_guest
# save
# poweroff
( back to host, you can also ctrl+] to kill qemu )
# ls
a_file_created_on_the_host a_file_create_on_the_guest

$ arm_now start armv5-eabi
# ./install_pkg_manager.sh
# opkg list
# opkg install gdb
# opkg install gdb_legacy // for mips32el
# opkg install python
# opkg install strace
# opkg install binutils
# opkg install gcc // might need more disk space and not always available.

This is not supported on all arch yet. Only mips32el, armv5-eabi, armv7-eabihf, and all x86 images.

• briged network

Press "Ctrl + ]" (Ctrl + altgr + ] on azerty).

It's based on buildroot, we download them from https://toolchains.bootlin.com/downloads/releases/toolchains/

Yes, it's a real virtual machine we use qemu-system-*. It's not a container or something based on chroot. You can fully debug any elf, all syscall are implemented.

Folks around the world to safely fuzz a program without breaking the host, or exploit/reverse a ctf challenge. If someone sends you a x86-64 binary that you don't trust just 'arm_now start x86-64 --sync' and you will be able to safely run it.

Ping me for any new writeups.

Go on freenode irc and "/join #arm_now cpu".

I do this project as a hobby, if you find bugs report and I will fix, the code source is very small about 300 lines of python, don't be afraid to pull request.

• Publish writeups :)
• A lot of cpu arch are still not supported, bfin, sparc .., at line 28 of arm_now.py you will find a dict that you can play with to add new cpu arch.
• search a package manager for all arch like => https://wiki.openwrt.org/about/mirrors or http://pkg.entware.net/binaries/
• full support of cpio rootfs
• make a script based on buildroot that will compile every existing arch ? this sounds like hours of work :/
• let the user choose the libc, (musl, glibc, uclibc) // this is very easy 10 min of work look at the code source and pull request !!
• allow the user to give any binary as input and start it in the right cpu arch, all dependencies should be automatically resolved and installed
• use buildroot to compile gdb or gdbserver for all arch, have look at utils/test-pkg. strace, ltrace are a plus. Having strace + ltrace + gdbserver on all arch is the goal. Please be awesome and contribute.
• add mac host support.

linux kernel, gcc, busybox, qemu, https://buildroot.org, https://toolchains.bootlin.com ...

By @chaignc #HexpressoTeam.