Always Innovating's Touch Book is probably close to what you want. The hardware specs are open, there are pins for serial on the board, and it can run a variety

Always Innovating's Touch Book is probably close to what you want. The hardware specs are open, there are pins for serial on the board, and it can run a variety of ARM based Linux distros (Android, Ubuntu, etc).: http://www.alwaysinnovating.com/touchbook/ http://www.alwaysinnovating.com/touchbook/ Plus the disassembly instructions are provided by the manufacturer: http://www.alwaysinnovating.com/wiki/index.php/Top_part http://www.alwaysinnovating.com/wiki/index.php/Top_part