Opened 11 years ago

Closed 9 years ago

#493 closed defect (fixed)

kcon breaks redrawing

Reported by: Hanka Sch. Owned by:
Priority: minor Milestone: 0.6.0
Component: helenos/unspecified Version: mainline
Keywords: gui Cc:
Blocker for: Depends on:
See also:


(Tested in Virtualbox and QEMU)

1) Type "kcon" in bdsh.
2) Move the mouse around, the mouse cursor draws portions of the user space output over the kernel console (you'll get a drawing tool :))
3) Type "continue" in the kernel console.
4) From now on also Alt+M breaks redrawing.

Notice 1: Alt+M works if there's no "kcon" used before.
Notice 2: In release HelenOS-0.5.0-ia32 similar problem of broken redrawing appears after writing "continue" in kernel console (only) after using kcon.

Attachments (3)

kcon_01.png (48.2 KB ) - added by Hanka Sch. 11 years ago.
kcon_03_qemu.png (16.7 KB ) - added by Hanka Sch. 11 years ago.
kcon_continue_03_qemu.png (30.6 KB ) - added by Hanka Sch. 11 years ago.

Download all attachments as: .zip

Change History (9)

by Hanka Sch., 11 years ago

Attachment: kcon_01.png added

by Hanka Sch., 11 years ago

Attachment: kcon_03_qemu.png added

by Hanka Sch., 11 years ago

Attachment: kcon_continue_03_qemu.png added

comment:1 by Jiří Zárevúcky, 11 years ago

I don't think this should be considered a bug.
As has been stated on the mailing list, kernel console is a debugging tool, and although the behavior you have encountered makes it look quirky, it doesn't affect its function as far as I can tell.

comment:2 by Martin Decky, 11 years ago

The ticket describes multiple issues, some of them concern also incorrect redrawing after returning back from the kernel console. While I agree that these issues are not high priority and that the kernel console is a debugging mean, it should behave consistently. The "kcon" command should not break it more than Alt+M.

comment:3 by Jiri Svoboda, 11 years ago

IMHO the compositor should not draw to the kfb when kernel console is active, consistently with the behavior we had in the past for the console server. Claiming this is a debugging feature makes no sense, it would be trivial to implement an equivalent in the compositor itself (hit some key to fill the screen with some color).

comment:4 by Jiří Zárevúcky, 11 years ago

It makes some sense. If the compositor (or some other part of the GUI) blocks too long, it isn't possible to enter the kernel console. Currently, you can use GUI to some degree while in kernel console, thus bugs in the GUI won't affect your access to it.

Anyway, the way I see it, there is nothing this bug affect negatively apart from visuals when using kernel console, which is only supposed to be used by developers.

comment:5 by Jakub Jermář, 9 years ago


comment:6 by Martin Decky, 9 years ago

Resolution: fixed
Status: newclosed

As of mainline,2259 the separation between the kernel console and user space output should be finally completely waterproof. All the scenarios previously known to cause issues were debugged.

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