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Re: HOW2 test a frame-buffer?

Cross-posted to 3 groups.

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In article <je1ml9$3gs$1@dont-email.me>, no.top.post@gmail.com wrote: 

OK, here's the elementary info, which I wanted:--
because the framebuffer is a 'live' file/device you can use file access
to read/write it [probably] and see what it shows.

-> cat <a file>  > /dev/fb0
will write to the display, I tested in VT mode.
Perhaps <video buffer overflow: error> could be an error,
but for my test a 300KB file just <wrote pixels to the top 20% of
the screen.   My more advance question is below.

> An application that I need to have on a HP-mini netbook,
> needs a frame buffer.
> 
> When I did: cd /dev; ./MAKEDEV  -n -v  fb
> it showed :
> udev active, devices will be created in /dev/.static/dev/
> create fb0      c 29 0 root:video 0660
> create fb1      c 29 1 root:video 0660
> create fb2      c 29 2 root:video 0660
> create fb3      c 29 3 root:video 0660
> create fb4      c 29 4 root:video 0660
> create fb5      c 29 5 root:video 0660
> create fb6      c 29 6 root:video 0660
> create fb7      c 29 7 root:video 0660
> 
> Because the app. still failed, I did:
> ln -s /dev/.static/dev/fb0   /dev/fb0
> which made a difference: 
>  the VT-display, just blanks.
> 
> But I was able to 'key' to other VTs and
> Ctrl/C, Ctrl/D ..to free up the VT, which I
> had to re-login, after each test cycle.
> 
> My slak13 PC shows some info for `fbset`;
> but the netbook has got DebianEtch without any
> utilities to test the frame-buffer, that I can find.
> 
> How would I test the fb* facility independantly
> of my application?
> 
> == TIA.

On my PC:slak13 which has the normal /dev/fb0
the above described test is good.

On the HP:Win7:netbook with CF:Debian:Etch
-> cat <file>    >   /dev/.static/dev/fb0
== <-bash: no such device: /dev/.static/dev/>

And yet
-> ls -l /dev/.static/dev/fb*
shows all 8 of them.

-> mknod /dev/fb0  c  29  0
-> ls -l /dev/fb0  == good
-> cat <file>    >   /dev/fb0
== <-bash: no such device: /dev/.static/dev/>

So I'm wondering why, although `ls -l` sees </dev/*/fb0>,
apparently `bash` does not ?

== TIA.

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HOW2 test a frame-buffer? no.top.post@gmail.com - 2012-01-04 14:10 +0000
  Re: HOW2 test a frame-buffer? no.top.post@gmail.com - 2012-01-06 08:15 +0000
    Re: HOW2 test a frame-buffer? pacman@kosh.dhis.org (Alan Curry) - 2012-01-06 08:57 +0000
      Re (2): HOW2 test a frame-buffer? no.top.post@gmail.com - 2012-01-06 16:26 +0000
    Re: HOW2 test a frame-buffer? "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2012-01-06 23:18 -0500
      Re (2): HOW2 test a frame-buffer? no.top.post@gmail.com - 2012-01-08 05:35 +0000
      Re (3): HOW2 test a frame-buffer? no.top.post@gmail.com - 2012-01-08 15:42 +0000

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