In this section, we will explore how to unpack a firmware and update it with our custom firmware. We have noted that the firmware images will not include all the files to construct a complete system. Typically, we find the following:
- Bootloader (1st/2nd stage)
- Kernel
- File-system images
- User-land binaries
- Resources and support files
- Web-server/web-interface
In this section, we will utilize USBJTAG NT, while the USB connected to our Kali Linux and the JTAG is connected on the circuit board of the device. JTAG stands for Joint Test Action Group. It is an industry standard for verifying designs and testing printed circuit boards after manufacture.
JTAG can be used more from a TAP perspective no matter how restricted the device is. The manufacturer will usually leave either a serial port or a few TAPs (Test Access Port). In our experience, if the serial...