Some team of developers have managed on porting the open source operating system running on Apple’s A4-equippsde iOS devices, which means the iPad, iPhone 4, and the 4th generation iPod Touch. One of the main developers who has actually gotten this Linux port to run on an iPad is Patrick Wildt.

The below image show Linux booting on the iPad 1G:

No details have been reveled on how they managed to do this. However they plan to reveal more details in the future.

Source: ijailbreak