ofrak-u-boot

This repository shows strategies for using OFRAK to patch raw binary files.

Using PatchFromSourceModifier

The file u-boot-patch-commands.py is an example of patching the u-boot.bin binary. It does the following:

1. Extends binary to create a new RO_DATA segment
2. Patches the u-boot version command such that it returns Meow!
3. Patches the u-boot help command such that it calls version instead.

To try it out, run:

Run:

python3 u-boot-patch-commands.py

Build u-boot image

Setup and emulation steps here are based on Pandy's Blog, with minor updates for clarity. YMMV.

The u-boot asset was build using the following:

git clone https://github.com/ARM-software/u-boot.git
cd u-boot/
export CROSS_COMPILE=arm-linux-gnueabi-
make qemu_arm_defconfig
make

Emulate

To emulate the image (or the patched image), run:

qemu-system-arm -curses -machine virt -bios u-boot.bin

Esc + 1 can be used to go to qemu monitor command interface. Esc + 2 can be used to view the u-boot interface. To quit, run quit from the qemu monitor interface.