[LinuxBIOS] Accessibility of LinuxBios

Samuel Thibault samuel.thibault at ens-lyon.org
Mon Jul 3 01:26:22 CEST 2006


Hi,

Great to have so fast a reply :)

Stefan Reinauer, le Mon 03 Jul 2006 01:11:05 +0200, a écrit :
> * Samuel Thibault <samuel.thibault at ens-lyon.org> [060703 00:06]:
> > BIOSes is an area where accessibility is approximately non-existent.
> > Asking vendors to support hardware speech syntheses and braille devices
> > is quite dreamwork. I tried to convince accessibility people to release
> > basic drivers with BSD licenses so that vendors might integrate them,
> > but they just refused that, arguing that vendors will not make any
> > effort to integrate them, and there will always be bugs 
>  
> Maybe this code could be encapsulated, similar to how VGA
> bios or network boot is handled.

Indeed, except that it relies on serial or USB support, which might not
be easy to ship in a so encapsulated way.

> On the other hand, this would cut off quite some of the bringup from
> "visibility"

I'm sorry, my poor english couldn't understand that :)

> > LinuxBios, however, can be a great opportunity to have an accessible
> > BIOS.
> > 
> > So what can be done? If I understood well, LinuxBios is a linux kernel
> > -based bios. Does that mean that it has the notion of process, or does
> > it run only in kernel mode? (which is sufficient for taking advantage of
> > linux drivers).
> 
> LinuxBIOS initializes the machine just far enough so that it can run a
> Linux kernel from flash memory, hence the name. This in-flash Linux can
> run normal userspace programs as well as load another kernel from a
> hard disk or any other supported medium. 

Oh, great. That means that we can run the usual screen reader called
brltty, or any other such reader.

> usually we can say: the main information exchange with LinuxBIOS (before
> the kernel is started) is not via VGA but via serial, which i believe is
> in theory usable with a braille terminal connected to another machine. 
> (Is this correct?)

Yes. Minicom is quite accessible, so that's fine.

> The interaction part is all happening while Linux is loaded (ie. from flash)
> so we could use a local braille terminal at this point by using all the
> Linux utilities. 

Yup.

> One question is: how big is the Linux code to support one/some/many/all
> braille terminals and can we fit this in a 512kB/1MB flash part.
> The answer mostly depends on your needs.

Devices usually depend on serial or USB support, plus the /dev/vcsa
interface for reading the console's content.

Samuel




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