[Qemu-devel] Re: [PATCH 5/5] linux fbdev display driver.

[Stefano Stabellini]

On Tue, 15 Jun 2010, Gerd Hoffmann wrote:
> Display works, requires truecolor framebuffer with 16 or 32 bpp on the
> host.  32bpp is recommended.  The framebuffer is used as-is, qemu
> doesn't try to switch modes.  With LCD displays mode switching is pretty
> pointless IMHO, also it wouldn't work anyway with the most common
> fbdev drivers (vesafb, KMS).  Guest display is centered on the host
> screen.
> 
> Mouse works, uses /dev/input/mice.
> 
> Keyboard works.  Guest screen has whatever keymap you load inside
> the guest.  Text windows (monitor, serial, ...) have a simple en-us
> keymap.  Good enougth to type monitor commands.  Not goot enougth to
> work seriously on a serial terminal.  But the qemu terminal emulation
> isn't good enougth for that anyway ;)
> 
> Hot keys:
>   Ctrl-Alt-F<nr>  -> host console switching.
>   Ctrl-Alt-<nr>   -> qemu console switching.
>   Ctrl-Alt-ESC    -> exit qemu.
> 
> Special feature:  Sane console switching.  Switching away stops screen
> updates.  Switching back redraws the screen.  When started from the
> linux console qemu uses the vt you've started it from (requires just
> read/write access to /dev/fb0).  When starting from somewhere else qemu
> tries to open a unused virtual terminal and switch to it (usually
> requires root privileges to open /dev/tty<nr>).
> 
> For some strange reason console switching from X11 to qemu doesn't work.
> Anything else (including X11 -> text console -> qemu) works fine.  To be
> investigated ...
> 
> Can be enabled/disabled via monitor, use "change fbdev [ on | off ]"

the patch still doesn't use the display allocator interface, but it
shouldn't be difficult to implement support for it on top of this patch,
so it is fine by me.