# What's the simplest Linux capable board I could make at home?

I'd like to make a single board computer capable of booting Linux, with my low-tech garage tools (2 sided PCBs, reflow skillet, no plating through holes).

What's the simplest hardware design I could choose?

Are there any microcontrollers with enough onboard flash/RAM to run Linux/uCLinux?

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I'd like to see this too, but my gut instinct is to say "maybe, but it's a lot of work". Even the smallest Linux distro is going to need around a megabyte of RAM to run. This means at least 30 or so additional pins for the RAM controller in the microcontroller, and a couple of big RAM chips.

One of the simplest architectures I know that has Linux for it is the Atmel AVR32 series of parts. The smallest, the AT32UC3A0128 comes in a relatively hacker-friendly 100-pin TQFP package. This is at least amenable to hand-soldering, unlike most of the OS-capable embedded microcontrollers that come in BGA packages. (the chips that have the little solder balls underneath them) You can get an idea as to the complexity of a circuit using that chip by examining the EVK1100 eval board.

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That EVK1100 is a lot more complicated than is strictly necessary. Those kinds of eval boards usually have a lot of extra peripherals - things like LCDs, buttons and such that are there to give you a leg up on getting output from the chip. Making your own board you'll only include the things you care about and usually end up with a much simpler design. –  edebill Mar 5 '10 at 17:58
Most eval boards, definitely. The EVK1100 looks a bit better than many in by separating out those parts that are core and those that are peripherals. At least it seems like that from the pics, I don't have one. :) –  todbot Mar 6 '10 at 8:56

The Nintendo DS is capable of running uCLinux. You can get a used one for cheap, the only peripheral you need to run Linux on it is a microSD adapter (can be had for $15 from dealextreme.com) and a microSD (small ones are basically free these days) - Linuxstamp is probably your best bet. It's open and has the PCB drawings, schematics, etc available. But as far as doing it at home - probably not. There's some very fine pitches on some of the parts. You're welcome to try, but it seems like a fair bit of consternation to me. - Personally, I think it would be simpler to buy one rather than make one. A BeagleBoard is a pretty popular solution at$149.

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I absolutely agree. But, I want to make one :-) –  Toby Jaffey Mar 5 '10 at 0:10
+1 for having the ambition for such an undertaking. Best of luck. –  semaj Mar 5 '10 at 0:56

You pretty much need a decent size piece of RAM and flash outside the MCU/MPU. If I was going to make a bare bones Linux system, I think I would go with simple cheap ARM with a serial port. You could make a tiny PCB with 4MB of RAM, 2MB of FLASH, RS-232 transceiver, COM port, and the ARM. You could get real fancy by adding ethernet, but that won't add too much real estate to the PCB.

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Here is something a lot cheaper. If you really want to make your own, the schematic will be available.

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Thanks, that looks a lot like the LinuxStamp - opencircuits.com/Linuxstamp. The AT91RM9200 looks promising. –  Toby Jaffey Mar 5 '10 at 10:36

I agree that it is certainly cheaper/easier to buy one than to build one. There are a variety of solutions out there... Here are a few that I'm aware of:

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