[BRLTTY] initramfs

[Elias Oltmanns]

Hi Alastair,

"Alastair Irving" <alastairirving19 at hotmail.com> wrote:
> Hi All
>
> Just been looking at my /etc/init.d/brltty on ubuntu 7.04.  It includes
> a section of code to copy a brlty.conf from the initramfs to the main
> filesystem.  Does this mean that its possible to have brltty running
> from the initramfs?

I haven't had a look at the current Ubuntu release yet, but yes, its
generally possible to run BRLTTY from an initramfs.

> If so, has anyone on list successfully managed this? It would be nice
> to have brltty starting so early in the boot process.

Indeed, it is nice! But there are some issues to be taken into
consideration. On my system udev takes care to start and stop brltty
whenever a braille display is connected or disconnected. Unfortunately,
brltty chokes during the coldplug phase initiated by udev after the
change to the real root system has taken place. This means that I have
to stop brltty before coldplug is initiated. Arguably, all this is only
worth the effort if the boot sequence regularly stops somewhere during
initramfs stage in order to report something to the user or even
requires some input.

May be things have improved since I set it all up on my system but I'm
not sure whether there might not be other problems lurking in the
shadows if brltty is started on an initramfs and keeps running ever
after.

As I said, I don't know about the 7.04 release of
Ubuntu but on previous releases and on Debian there is not exactly a
straightforward procedure to achieve your goal. It'll require a bit of
reading and perhaps some experiments, I'm afraid. As always when
tampering with kernels and initrds, keep a working entry in your boot
loader's menu and make sure it doesn't get altered by the usual update
procedures. Have a look at the documentation for initramfs-tools, to
begin with. If you are still interested, I can send you snippets of the
scripts I installed under /etc/initramfs-tools/(hooks|scripts). Please
note, however, that things may well turn out differently on your system
due to the progress of the transition from init to startup in Ubuntu.

Regards,

Elias