This contains the modified Linux kernel for the EMBA emulation framework, which includes an in-tree firmadyne module to perform instrumentation and emulation.
This module can be configured using the following parameters:
| Parameter | Default | Values | Description |
|---|---|---|---|
| devfs | 1 (on) | 0, 1 | Create stubs in devfs and emulate behavior |
| execute | 1 (on) | 0 - 5 | Counter to execute /firmadyne/console after 4th execve() syscall (requires syscall hooks), 0 to disable |
| reboot | 1 (on) | 0, 1 | Attempt to emulate system reboot by re-executing /sbin/init |
| procfs | 1 (on) | 0, 1 | Create stubs in procfs and emulate behavior |
| syscall | 255 (all) | 0 - 16 | Output log bitmask for hooking system calls using the kprobe framework, 0 to disable |
Since MIPS systems can be either big-endian or little-endian, this kernel should be compiled for both endianness. The below instructions produce a little-endian (mipsel) kernel, but should be repeated for a big-endian (mipseb) kernel.
Create the kernel build output directory:
mkdir -p build/mipsel
Copy the configuration file into the build directory:
cp config.mipsel build/mipsel/.config
Assuming that the appropriate cross-compiler is installed in /opt/cross/mipsel-linux-musl, execute:
make ARCH=mips CROSS_COMPILE=/opt/cross/mipsel-linux-musl/bin/mipsel-linux-musl- O=./build/mipsel -j8
The output kernel image will be generated at the following location:
build/mipsel/vmlinux
Create the kernel build output directory:
mkdir -p build/mipseb
Copy the configuration file into the build directory:
cp config.mipseb build/mipseb/.config
Assuming that the appropriate cross-compiler is installed in /opt/cross/mipseb-linux-musl, execute:
make ARCH=mips CROSS_COMPILE=/opt/cross/mipseb-linux-musl/bin/mipseb-linux-musl- O=./build/mipseb -j8
The output kernel image will be generated at the following location:
build/mipseb/vmlinux
This instrumented MIPS kernel is built for the ARCH_MALTA
MIPS Malta
target with a 24kf processor. As a result, hardware support on this
emulated target is limited to peripherals that are both available on the
emulated target and supported by QEMU. Since an emulated PCI bus is available
and supported, this allows additional ethernet devices (e.g. rtl8139,
smc91c111, pcnet32, etc.) to be attached to the virtualized system.
Emulated hard drives can be attached using the IDE block device interface.
As future work, it may be useful to switch to VirtIO on MIPS, since support has been recently merged into the Linux kernel. However, this would require a kernel upgrade. Additionally, it may be useful to add support for MIPS64 systems, although these do not appear to be prevalent. Nevertheless, at the time, we performed our published experiments over our dataset using this kernel for MIPS systems.
Pull requests are greatly appreciated!