FB driver for graphic hardware compatible with VESA Bios Extension Real mode interface utilized Tested on real HW. More...

#include <inttypes.h>
#include <bsp.h>
#include <bsp/fb_default_mode.h>
#include <bsp/fb_vesa.h>
#include <bsp/realmode_int.h>
#include <pthread.h>
#include <rtems/libio.h>
#include <rtems/fb.h>
#include <rtems/framebuffer.h>
#include <rtems/score/atomic.h>
#include <stdlib.h>

Data Structures
struct	Mode_params
	Basic graphic's mode parameters. More...

Macros
#define	FB_VESA_NAME "FB_VESA_RM"

#define	MAX_NO_OF_SORTED_MODES 100

Enumerations
enum	mode_err_ret_val { NO_SUITABLE_MODE = -1 , BAD_FORMAT = -2 , AUTO_SELECT = -3 , DONT_INIT = -4 , NO_MODE_REQ = -5 , NO_SUITABLE_MODE = -1 , BAD_FORMAT = -2 , AUTO_SELECT = -3 , DONT_INIT = -4 , NO_MODE_REQ = -5 }

Functions
void	vesa_realmode_bootup_init (void)
	Initializes VBE framebuffer during bootup.

uint32_t	VBE_controller_information (VBE_vbe_info_block *info_block, uint16_t queried_VBE_Version)
	Returns information about graphic's controller in the `info_block` structure.

uint32_t	VBE_mode_information (VBE_mode_info_block *info_block, uint16_t mode_number)
	Fills structure `info_block` with informations about selected mode in `mode_number` variable.

uint32_t	VBE_set_mode (uint16_t mode_number, VBE_CRTC_info_block *info_block)
	Sets graphics mode selected. If mode has refreshRateCtrl bit set, than the `info_block` must be filled accordingly.

uint32_t	VBE_current_mode (uint16_t *mode_number)
	Get currently set mode number.

uint32_t	VBE_report_DDC_capabilities (uint16_t controller_unit_number, uint8_t seconds_to_transfer_EDID_block, uint8_t DDC_level_supported)
	Gets information about display data channel implemented in the graphic's controller.

uint32_t	VBE_read_EDID (uint16_t controller_unit_number, uint16_t EDID_block_number, EDID_edid1 *buffer)
	Reads selected EDID block from display attached to controller's interface.

rtems_device_driver	frame_buffer_initialize (rtems_device_major_number major, rtems_device_minor_number minor, void *arg)
	Frame Buffer Initialization Entry Point.

rtems_device_driver	frame_buffer_open (rtems_device_major_number major, rtems_device_minor_number minor, void *arg)
	Frame Buffer Open Entry Point.

rtems_device_driver	frame_buffer_close (rtems_device_major_number major, rtems_device_minor_number minor, void *arg)
	Frame Buffer Close Entry Point.

rtems_device_driver	frame_buffer_read (rtems_device_major_number major, rtems_device_minor_number minor, void *arg)
	Frame Buffer Read Entry Point.

rtems_device_driver	frame_buffer_write (rtems_device_major_number major, rtems_device_minor_number minor, void *arg)
	Frame Buffer Write Entry Point.

rtems_device_driver	frame_buffer_control (rtems_device_major_number major, rtems_device_minor_number minor, void *arg)
	Frame Buffer IO Control Entry Point.

Variables
const char *const	rtems_fb_default_mode
	Allows to enable initialization of VESA real mode driver from an application by setting the value of this variable to non null value in user's module. The value of this variable will be then updated when linked with application's object.

Detailed Description

FB driver for graphic hardware compatible with VESA Bios Extension Real mode interface utilized Tested on real HW.

Public sources related:

VESA BIOS EXTENSION (VBE) Core Function Standard, Ver: 3.0, Sep 16, 1998
VESA Enhanced Extended Display Identification Data (E-EDID) Standard Release A, Revision 2, September 25, 2006

Hardware is completely initialized upon boot of the system. Therefore there is no way to change graphics mode later.

Interrupt 0x10 is used for entering graphics BIOS.

Driver reads parameter from multiboot command line to setup video: "--video=<resX>x<resY>[-<bpp>]" "--video=auto" - try EDID to find mode that fits the display attached best "--video=none" / "--video=off" - do not initialize the driver If cmdline parameter is not specified the rtems_fb_default_mode variable content is tested (see doc below). Command line option has higher priority. rtems_fb_default_mode is probed only if cmdline "--video=" is not specified at all.

If neither of the above options is specified the driver is not initialized.

Function Documentation

◆ frame_buffer_close()

rtems_device_driver frame_buffer_close	(	rtems_device_major_number	major,
		rtems_device_minor_number	minor,
		void *	arg
	)

Frame Buffer Close Entry Point.

This method closes a specific device supported by the frame buffer device driver.

Parameters

[in]	major	is the device driver major number
[in]	minor	is the device driver minor number
[in]	arg	is the parameters to this call

Returns: This method returns RTEMS_SUCCESSFUL when the device is successfully closed.

◆ frame_buffer_control()

rtems_device_driver frame_buffer_control	(	rtems_device_major_number	major,
		rtems_device_minor_number	minor,
		void *	arg
	)

Frame Buffer IO Control Entry Point.

This method performs an IO Control operation on a specific device supported by the frame buffer device driver.

Parameters

[in]	major	is the device driver major number
[in]	minor	is the device driver minor number
[in]	arg	is the parameters to this call

Returns: This method returns RTEMS_SUCCESSFUL when the device driver IO control operation is successfully performed.

◆ frame_buffer_initialize()

rtems_device_driver frame_buffer_initialize	(	rtems_device_major_number	major,
		rtems_device_minor_number	minor,
		void *	arg
	)

Frame Buffer Initialization Entry Point.

This method initializes the frame buffer device driver.

Parameters

[in]	major	is the device driver major number
[in]	minor	is the device driver minor number
[in]	arg	is the parameters to this call

Returns: This method returns RTEMS_SUCCESSFUL when the device driver is successfully initialized.

◆ frame_buffer_open()

rtems_device_driver frame_buffer_open	(	rtems_device_major_number	major,
		rtems_device_minor_number	minor,
		void *	arg
	)

Frame Buffer Open Entry Point.

This method opens a specific device supported by the frame buffer device driver.

Parameters

[in]	major	is the device driver major number
[in]	minor	is the device driver minor number
[in]	arg	is the parameters to this call

Returns: This method returns RTEMS_SUCCESSFUL when the device driver is successfully opened.

◆ frame_buffer_read()

rtems_device_driver frame_buffer_read	(	rtems_device_major_number	major,
		rtems_device_minor_number	minor,
		void *	arg
	)

Frame Buffer Read Entry Point.

This method reads from a specific device supported by the frame buffer device driver.

Parameters

[in]	major	is the device driver major number
[in]	minor	is the device driver minor number
[in]	arg	is the parameters to this call

Returns: This method returns RTEMS_SUCCESSFUL when the device is successfully read from.

◆ frame_buffer_write()

rtems_device_driver frame_buffer_write	(	rtems_device_major_number	major,
		rtems_device_minor_number	minor,
		void *	arg
	)

Frame Buffer Write Entry Point.

This method writes to a specific device supported by the frame buffer device driver.

Parameters

[in]	major	is the device driver major number
[in]	minor	is the device driver minor number
[in]	arg	is the parameters to this call

Returns: This method returns RTEMS_SUCCESSFUL when the device is successfully written.

◆ VBE_controller_information()

uint32_t VBE_controller_information	(	VBE_vbe_info_block *	info_block,
		uint16_t	queried_VBE_Version
	)

Returns information about graphic's controller in the info_block structure.

Parameters

[out]	info_block	pointer to the struct to be filled with controller information
[in]	queried_VBE_Version	if >0x200 then video bios is asked to fill in parameters which appeared with second version of VBE.

Return values

ax	register content as defined in VBE RETURN STATUS paragraph
-1	error calling graphical bios

◆ VBE_current_mode()

uint32_t VBE_current_mode ( uint16_t * mode_number )

Get currently set mode number.

Parameters

[out] mode_number variable to be filled with current mode number

Return values

ax	register content as defined in VBE RETURN STATUS paragraph
-1	error calling graphical bios

◆ VBE_mode_information()

uint32_t VBE_mode_information	(	VBE_mode_info_block *	info_block,
		uint16_t	mode_number
	)

Fills structure info_block with informations about selected mode in mode_number variable.

Parameters

[out]	info_block	pointer to the struct to be filled with mode information
[in]	mode_number	detailes of this mode to be filled

Return values

ax	register content as defined in VBE RETURN STATUS paragraph
-1	error calling graphical bios

◆ VBE_read_EDID()

uint32_t VBE_read_EDID	(	uint16_t	controller_unit_number,
		uint16_t	EDID_block_number,
		EDID_edid1 *	buffer
	)

Reads selected EDID block from display attached to controller's interface.

Parameters

[in]	controller_unit_number
[in]	EDID_block_number	block no. to be read from the display
[out]	buffer	place to store block fetched from the display

Return values

ax	register content as defined in VBE RETURN STATUS paragraph
-1	error calling graphical bios

◆ VBE_report_DDC_capabilities()

uint32_t VBE_report_DDC_capabilities	(	uint16_t	controller_unit_number,
		uint8_t *	seconds_to_transfer_EDID_block,
		uint8_t *	DDC_level_supported
	)

Gets information about display data channel implemented in the graphic's controller.

Parameters

[in]	controller_unit_number
[out]	seconds_to_transfer_EDID_block	approximate time to transfer one EDID block rounded up to seconds
[out]	DDC_level_supported	contains DDC version supported and screen blanking state during transfer

Return values

ax	register content as defined in VBE RETURN STATUS paragraph
-1	error calling graphical bios

◆ VBE_set_mode()

uint32_t VBE_set_mode	(	uint16_t	mode_number,
		VBE_CRTC_info_block *	info_block
	)

Sets graphics mode selected. If mode has refreshRateCtrl bit set, than the info_block must be filled accordingly.

Parameters

[in]	mode_number	number of mode to be set
[in]	info_block	pointer to struct containing refresh rate control info

Return values

ax	register content as defined in VBE RETURN STATUS paragraph
-1	error calling graphical bios

◆ vesa_realmode_bootup_init()

void vesa_realmode_bootup_init ( void )

Initializes VBE framebuffer during bootup.

utilizes switches to real mode interrupts and therefore must be called during bootup before tick is set up and real-time interrupt vectors utilized

Variable Documentation

◆ rtems_fb_default_mode

const char* const rtems_fb_default_mode

Allows to enable initialization of VESA real mode driver from an application by setting the value of this variable to non null value in user's module. The value of this variable will be then updated when linked with application's object.

Further the value should point to string in the following format: "<resX>x<resY>[-<bpp>]" - e.g. "1024x768-32" "auto" - try EDID to find mode that fits the display attached best "none" / "off" - do not initialize the driver the given parameters are used if applicable.

Command line argument "--video=" has priority over this string.

Data Structures

Macros

Enumerations

Functions

Variables

Detailed Description

Function Documentation

◆ frame_buffer_close()

◆ frame_buffer_control()

◆ frame_buffer_initialize()

◆ frame_buffer_open()

◆ frame_buffer_read()

◆ frame_buffer_write()

◆ VBE_controller_information()

◆ VBE_current_mode()

◆ VBE_mode_information()

◆ VBE_read_EDID()

◆ VBE_report_DDC_capabilities()

◆ VBE_set_mode()

◆ vesa_realmode_bootup_init()

Variable Documentation

◆ rtems_fb_default_mode