Talking with the systemd-consoled people (Was: the push to get rid of CONFIG_VT in the kernel and the future of Speakup)

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Hello,

It is quite a coincidence that I happen to have talked with some people
working on systemd-consoled the other day at the XDC2014 conference. I
was thus able to discuss the concern about CONFIG_VT "going away" with
them, and there are quite a few reassuring points:

- the CONFIG_VT option is here to stay, even if some production systems
will indeed disable it (such as embedded devices and such); I believe a
lot of kernel hackers and such will keep it enabled, and thus it will be
kept maintained;

- on production systems where CONFIG_VT is not available, sighted users
will not see kernel boot messages etc. until the userland console gets
started (and a userland screen reader thus has the opportunity to get
started too). Those kernels have no text rendering except one thing I'll
discuss below; everything should be available to the userland screen
reader, so it means that blind people have no less access to what the
computer says than sighted people, be it normal work or boot messages.
If boot messages are needed to debug something before systemd-consoled
and screen reader are started, sighted users will need some way to get
them anyway, and such kind of way (CONFIG_VT, serial console, network
console, etc.) is already accessible to blind users.

- the only text rendering done by the kernel is oops messages.  In the
cases where that ends up with a kernel hangup (so-called kernel panic),
speakup can not work any more anyway, be it with CONFIG_VT or not, so
there is no regression here, at least.  Unfortunately that case can't
really be made accessible: writing text to video memory is possible in
that case, interacting with the user to access the screen is not really
(no interrupts, etc.). So a serial console is needed to debug such case.
In the cases where that doesn't end up with a kernel panic, a syslog
notification is enough to get the oops message.

- I could discuss with a developper of systemd-consoled, to explain him
what requirements speakup and such screen readers have, to get the content
of the console: screen content and stream of text.  He understood it
well, and is willing to provide the support.

Samuel