Hello, Gentoo.

A new kernel, gentoo-sources-5.10.49-r1 has become current.

For those who wish to have console soft scrolling, the patch which worked
with 5.10.27 actually still works in 5.10.49-r1.  But I've tidied that
patch up somewhat for 5.10.49-r1 and have attached the patch file to this
post.

The instructions for using it are basically unchanged, apart from file
names, etc.  Updating those instructions gives us:
(i) Extract the attached patch file to your
  /usr/src/linux-5.10.49-gentoo-r1 directory (or probably any 5.10
  kernel's).
(ii) From that directory run $ patch -p0 < 5.10.49-scroll.20210715.diff.
(iii)(a) If you've already got a working 5.10.49-r1, do a $ make oldconfig.
  That should bring up the new configuration items, for which you can
  accept the defaults.  These two items are a flag to enable the
  scrollback, and a buffer size defaulting to 128kB.
(iii)(b) If you haven't yet got a 5.10.49-r1, just configure your kernel
  in the usual way.  The two new items are under Device Drivers/Graphics
  support/Console display driver support.
(iv) Build the kernel.
(v) Put the new kernel into your usual boot manager.
(vi) Reboot and enjoy!

As before, it works for me, and there's nothing malicious in it, but if
it breaks for you, I'm sorry but I won't be responsible.

-- 
Alan Mackenzie (Nuremberg, Germany).



On Mon, Apr 05, 2021 at 17:12:07 +0000, Alan Mackenzie wrote:
> Hello, Gentoo.

> Yes, console soft scrolling is back!  That essential feature that was
> stripped out of the kernel at around 5.4.x has returned!

> Only this time, it's even better!  Instead of one scrollback buffer
> shared between all tty's, there's now a buffer for each tty.

> How to get it working:
> (i) Extract the enclosed patch file to your /usr/src/linux-5.10.27-gentoo
> directory (or probably any 5.10 kernel's).
> (ii) From that directory run $ patch -p0 < diff.20210405.diff.
> (iii)(a) If you've already got a working 5.10.27, do a $ make oldconfig.
>   That should bring up the new configuration items, for which you can
>   accept the defaults.  These two items are a flag to enable the
>   scrollback, and a buffer size defaulting to 128kB.
> (iii)(b) If you haven't yet got a 5.10.27, just configure your kernel in
>   the usual way.  The two new items are under Device Drivers/Graphics
>   support/Console display driver support.
> (iv) Build the kernel.
> (v) Put the new kernel into your usual boot manager.
> (vi) Reboot and enjoy!

> Admittedly, the exercise isn't quite finished - the patched source files
> still have my personal change markings in them, to make debugging easier.
> But the problems I reported here a few days ago are now solved.  One or
> two features haven't (yet) been implemented - having a single scroll
> buffer shared amongst all tty's isn't there, and there're no kernel
> command line parameters to control the feature.

> Also, you may wonder about how safe the patch is.  All I can say is that
> there is nothing malicious in it, and I am known on this list, but of
> course if it breaks I won't be to blame.

> Bug reports and other comments are welcome, of course.

> If anybody would like the corresponding patch which works on 5.4.n, for n
> >= 80, that is available, too.

> -- 
> Alan Mackenzie (Nuremberg, Germany).