SD Card read/write errors and NSOD

Andy Green andy at
Mon Mar 9 16:37:23 CET 2009

Hash: SHA1

Somebody in the thread at some point said:
| 2009/3/9 Andy Green <andy at <mailto:andy at>>
|     [...]
|     What does the "noise" look like, is it also the top-down block of
|     "random" pixels described on the trac
|     or "jazzy" moving pixels, or all over the screen, or in a defined
|     invalidated area not redrawn or what?
| The screen is full of random pixels, but not uniform as in the trac
| ticket snapshot.

Hm that guy had an encrypted FS which was suspected as the source of the
entropy, because it's actually real tough to just happen across good
random-looking data coming out of nowhere.  So this also makes it sound
like SD Card blocks end up in the framebuffer region, in your case
they'll full of more normally distributed file contents maybe.

| Touching the TS sometimes update a random part of the screen with other
| random pixels.
| I'll try to reproduce and take a snapshot asap.

Is the random part of the screen always a linear set of vertical lines?
~ Ie, never a 64 x 64 or such pixel square in its own world but always a
linear block of framebuffer memory?

- -Andy
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Fedora -


More information about the community mailing list