80 lines
2.7 KiB
Plaintext
80 lines
2.7 KiB
Plaintext
This driver for x86 VBE 2.0 flat framebuffers was implemented by Sebastian
|
|
Sumpf.
|
|
|
|
|
|
Building instructions
|
|
~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
* 'specs.conf': set 'SPECS' variable, enable at least the following specs:
|
|
'genode' 'fiasco' 'fiasco_x86'. Also, add the location of the
|
|
'framebuffer_session' include files to your include search path, e.g.,
|
|
'INC_DIR += <genode dir>/demo/include'
|
|
|
|
* Compile; the target will be called 'fb_drv' --> Good luck
|
|
|
|
Config arguments
|
|
~~~~~~~~~~~~~~~~
|
|
|
|
By default, the driver sets up a resolution of 1024x768 at 16 bit color
|
|
depth. This behaviour can be overridden by supplying the following
|
|
arguments via Genode's config mechanism:
|
|
|
|
! <config width="1024"
|
|
! height="768"
|
|
! depth="16"
|
|
! buffered="no" />
|
|
|
|
The 'depth' attribute is specified in bits per pixel. If setting the
|
|
'buffered' attribute to 'yes', the VESA driver hands out a plain
|
|
memory buffer to its client and flushes the pixels to the physical
|
|
frame buffer each time, 'refresh' is called by the client. Buffered
|
|
output should be used if the client tends to read from the frame
|
|
buffer (i.e., the client performs output with alpha channel).
|
|
|
|
Note that only VESA modes but no arbitrary combination of values are
|
|
supported. To find out which graphics modes exist on your platform,
|
|
you might use the 'vbeprobe' command of the GRUB boot loader. Also,
|
|
the driver will print a list of supported modes if the specified
|
|
values are invalid.
|
|
|
|
As an alternative to letting the VESA driver set up a screen mode, the
|
|
driver is able to reuse an already initialized mode, which becomes useful
|
|
if the VESA mode is already initialized by the boot loader. If the screen
|
|
is initialized that way, the 'preinit' attribute of the 'config' node can
|
|
be set to '"yes"' to prevent the driver from changing the mode. This way,
|
|
the driver will just query the current mode and make the already
|
|
initialized framebuffer available to its client.
|
|
|
|
|
|
Options and usage from clients
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
:Example:
|
|
|
|
! #include <framebuffer_session/connection.h>
|
|
!
|
|
! ...
|
|
!
|
|
! /* create session to frame-buffer service */
|
|
! Framebuffer::Connection framebuffer(1024, 768, Framebuffer::Session::RGB565);
|
|
!
|
|
! /* retrieve frame buffer dataspace */
|
|
! Dataspace_capability fb_ds_cap = framebuffer.dataspace();
|
|
!
|
|
! /* map dataspace to local address space */
|
|
! void *local_addr = env()->rm_session()->attach(fb_ds_cap);
|
|
|
|
:Session-creation arguments:
|
|
|
|
:'fb_width': resolution width in pixel
|
|
|
|
:'fb_height': resolution height in pixel
|
|
|
|
:'fb_mode ': bits per pixel
|
|
|
|
:Supported modes:
|
|
|
|
'640x480', '800x600', '1024x786', '1280x1024' at 15, 16, 24, 32 bits per pixel
|
|
Buffered output is only supported for modes using 16 bits per pixel.
|
|
|