Hacking PCI Express on the Raspberry Pi 4 #Hacking #RaspberryPi4 #ReverseEngineering @domipheus @Raspberry_Pi
Via Twitter we learn of Colin Riley’s work using PCI Express (PCIe) on the new Raspberry Pi 4. Colin’s blog post documents the process in detail.
Recently, Tomasz Mloduchowski posted a popular article on his blog detailing the steps he undertook to get access to the hidden PCIe interface of Raspberry Pi 4: the first Raspberry Pi to include PCIe in its design. After seeing his post, and realizing I was meaning to go buy a Raspberry Pi 4, it just seemed natural to try and replicate his results in the hope of taking it a bit further. I am known for Raspberry Pi Butchery, after all.
This is NOT for the faint of heart but IS for a lovely time hacking. It involves removing the chip providing USB 3 to access the small pads connecting the PCIe bus to the CPU.
The signal wires, undocumented, are laid out in the post:
Hackers are looking to use inexpensive PCIe riser cards to interface PC type hardware like USB, network, and even GPU cards.
On the software side, some changes in device tree settings is required but: IT WORKS!
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