On 10/10/13 18:48, alexey.kurin...@gmail.com wrote: > In the tread about board for openbsd router I strengthened desire to use > alix. > Existing arm single boards very intresting, but with it I have more > questions than answers. My experiense and skils not enough for solutions > existing problems. > Anyway threads about armv7 interest me. > > Can anyone answer for lamers like me - is the drivers for i386 or amb64 > is depends from architecture and use it on arm need porting? Or just > nedd to compil kernel with needed drivers? > Short question is - device drivers at all, or just for example usb > ethernet is crossplatform?
This is a huge over-simplification, but devices are a combination of how you work the device and how you talk to the device. Drivers aren't for i386/amd64, they are for (for example) an Intel 82557 NIC on a PCI bus (fxp(4)), or a RT2800U on a USB bus (run(4)). The fxp(4) can be used on anything with a PCI bus, and the run(4) can be used on anything with a USB bus. A device chain might go something like this: CPU -> PCI bus -> PCI-PCI Bridge -> USB interface -> USB Hub -> USB NIC (now go look at a dmesg...you will see exactly these kind of chains) Once a particular device is supported, it is just a matter of getting the stuff /up to/ its interface supported. So again on the MacPPC platform, the PCI bus is supported so you can plug PCI cards into a mac that MacOS would never have dreamed of supporting and they will Just Work on OpenBSD. You could plug a USB2 PCI card into a MacPPC, and then plug a USB wireless adapter into the USB2 card. Sometimes it can get pretty surreal -- iirc, there is a PCMCIA slot adapter available for the SBus SPARC machines, which OpenBSD supports (supported? not sure anyone uses this enough to guarantee it is still working). So...you can take a SparcStation 20, put a PCMCIA adapter in it, plug a USB port into the PCMCIA slot, and plug a wireless device into the USB port...and make your sparcstation 20 work on a wireless network, something the original designers may never have imagined. (major exception: if the driver was written by someone with an i386 mindset, it may not work on anything else without some TLC, typically endian issues. And sometimes if the combination is really obscure, it may never have been tested.) Now to your specific question: OpenBSD does not yet support the USB port on the Beaglebone Black...but once that is done, then yes, a whole lot of USB devices should Just Work. Until then, none of them will work. Nick.
