[blfs-support] problem using BS or DEL key

Alexey Orishko alexey.orishko at gmail.com
Fri Dec 6 05:26:24 PST 2013

On Thu, Dec 5, 2013 at 11:01 PM, Ken Moffat <zarniwhoop at ntlworld.com> wrote:
>  I still think my suggestion of checking every key will identify if
> any of the keys are being garbled in the kernel, and therefore if
> this is a kernel _input_ problem.
>  But here is an alternative train of thought :
>  When you trigger the garbage, is it really there, or only in the
> screen output ?  Start a command with '#' so that it is treated as a
> comment, type, do whatever you need to so that the spurious garbage
> appears, then press enter.  And make a written note of exactly what
> you typed, and a guide to what appeared and where it was on the
> line, so that you can repeat the test.

1. Typed:
# kkkkk     kkkkkk
2. Then deleted 2 speces between kkk-s with BS
3. white blocks  appeared on the same line till the end of the screen

>  Then key enter again : does the garbage scroll up, so that the
> current line is empty apart from the prompt ?
It does scroll up

>  Then key the up-arrow once to see the last line of history - is the
> garbage there in the history ?
No, it's not there (not in bash history)

>  If the garbage is only on the screen then I guess it _is_ a kernel
> problem, but in the _video_ driver (i915 I suppose, but maybe you
> compiled in vga).
 I will rebuild kernel

>  Your LatArCyrHeb font has two, possibly three, characters which
> match a "white square".  If you manage to prove that it is a kernel
> video problem, can you please "loadkeys LatGrkCyr-8x16" and repeat
> the test.  I'm guessing you will get a capital T with a comma below
> it (either U+021A or, in that font, U+0162), or a capital U with an
> acute accent (U+00DA), or else a capital U with a breve (U+016C).
> Knowing what appears might be useful if this is a bug in a video
> driver.  I'll attach the text listing of that font - I'm guessing it
> is one of character positions 210, 212, or 216.

Do you mean setfont instead of loadkeys? Screen font changed, but
white block is still the same while using LatGrkCyr-8x16.
If I select viscii10-8x16 I can see blinking white letter U with diacritics on
a grey background. It is a last letter in showconsolefont.
If Iset lat1-16 I see "y" (U+00FF)

>  If it is a video-driver problem, please attach the relevant part of
> your kernel config

I will recompile with:
Graphics support  --->
    <*> Intel GMA5/600 KMS Framebuffer
    [*]   Intel GMA3600/3650 support (Experimental)

>  And, which kernel is this ?
I'm going to build a latest stable from kernel.org 3.10.22


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