July 30, 2012 posted by Mike M. Volokhov
Demand for a cheap yet powerful computer is pretty high in geek circles. Remember those days when you could take a ZX Spectrum, or Commodore 64, or something like that and attach it to your TV to fill next few days with a great fun. Since then, PCs pushed out these tiny home computers. But today, Raspberry Pi — a little credit-card sized sweet computer — is here.
The Raspberry Pi is built on Broadcom BCM2835 system on chip which contains ARM1176 core running at 700MHz, with VideoCore 4 GPU, and has 256 MB of RAM on board. It provides two USB ports, 100Mb/s Ethernet, HDMI and composite video; audio output presented as well. Operating system loaded from SD flash.
Yet more fun is that the initial NetBSD support was just committed to the NetBSD source tree, and the Raspberry Pi can boot into multiuser now. Currently work on device drivers is in progress. USB and Ethernet are planned to be supported next.
Generally, NetBSD support for the ARM1176 core is in very good shape. The largest parts of the code I committed were the update to the plcom serial driver and the infrastructure to support the low level parts of the bcm2835 (interrupt controller, bus_space, and timer) — says Nick Hudson, who did the bringup. However, the porting has some hard nuts to crack:
The graphics part is a bit of a challenge. But I hope to get dumb framebuffer support relatively soon. There is a publicly available datasheet for part of bcm2835, but certainly not the video controller.
Matt Thomas, the port-evbarm portmaster, was very knowledgeable and helpful in answering all my questions. I'd like to also thank Stephen Borrill for getting me an RPI in the first place. Stephen spoke to Eben Upton in Cambridge and soon after an RPI arrived — adds Nick.
So, there is a boot log from the very first NetBSD driven RPI board, and work on the device is in full swing. Many people exposed interest, and eventually the Raspberry Pi could became a good alternative for number of well supported, but aging single board computers.