Frame Buffer Memory¶

intremove_conflicting_framebuffers(struct apertures_struct * a, const char * name, bool primary)¶

remove firmware-configured framebuffers

Parameters

structapertures_struct*a

memory range, users of which are to be removed

constchar*name

requesting driver name

boolprimary

also kick vga16fb if present

Description

This function removes framebuffer devices (initialized by firmware/bootloader)which use memory range described bya. Ifa is NULL all such devices areremoved.

intremove_conflicting_pci_framebuffers(struct pci_dev * pdev, const char * name)¶

remove firmware-configured framebuffers for PCI devices

Parameters

structpci_dev*pdev

PCI device

constchar*name

requesting driver name

Description

This function removes framebuffer devices (eg. initialized by firmware)using memory range configured for any ofpdev’s memory bars.

The function assumes that PCI device with shadowed ROM drives a primarydisplay and so kicks out vga16fb.

intregister_framebuffer(struct fb_info * fb_info)¶

registers a frame buffer device

Parameters

structfb_info*fb_info

frame buffer info structure

Registers a frame buffer devicefb_info.

Returns negative errno on error, or zero for success.

voidunregister_framebuffer(struct fb_info * fb_info)¶

releases a frame buffer device

Parameters

structfb_info*fb_info

frame buffer info structure

Unregisters a frame buffer devicefb_info.

Returns negative errno on error, or zero for success.

This function will also notify the framebuffer consoleto release the driver.

This is meant to be called within a driver’smodule_exit()function. If this is called outsidemodule_exit(), ensurethat the driver implements fb_open() and fb_release() tocheck that no processes are using the device.

voidfb_set_suspend(struct fb_info * info, int state)¶

low level driver signals suspend

Parameters

structfb_info*info

framebuffer affected

intstate

0 = resuming, !=0 = suspending

This is meant to be used by low level drivers tosignal suspend/resume to the core & clients.It must be called with the console semaphore held

Frame Buffer Colormap¶

voidfb_dealloc_cmap(struct fb_cmap * cmap)¶

deallocate a colormap

Parameters

structfb_cmap*cmap

frame buffer colormap structure

Deallocates a colormap that was previously allocated withfb_alloc_cmap().

intfb_copy_cmap(const struct fb_cmap * from, struct fb_cmap * to)¶

copy a colormap

Parameters

conststructfb_cmap*from

frame buffer colormap structure

structfb_cmap*to

frame buffer colormap structure

Copy contents of colormap fromfrom toto.

intfb_set_cmap(struct fb_cmap * cmap, struct fb_info * info)¶

set the colormap

Parameters

structfb_cmap*cmap

frame buffer colormap structure

structfb_info*info

frame buffer info structure

Sets the colormapcmap for a screen of deviceinfo.

Returns negative errno on error, or zero on success.

const struct fb_cmap *fb_default_cmap(int len)¶

get default colormap

Parameters

intlen

size of palette for a depth

Gets the default colormap for a specific screen depth.lenis the size of the palette for a particular screen depth.

Returns pointer to a frame buffer colormap structure.

voidfb_invert_cmaps(void)¶

invert all defaults colormaps

Parameters

void

no arguments

Description

Invert all default colormaps.

Frame Buffer Video Mode Database¶

intfb_try_mode(struct fb_var_screeninfo * var, struct fb_info * info, const struct fb_videomode * mode, unsigned int bpp)¶

test a video mode

Parameters

structfb_var_screeninfo*var

frame buffer user defined part of display

structfb_info*info

frame buffer info structure

conststructfb_videomode*mode

frame buffer video mode structure

unsignedintbpp

color depth in bits per pixel

Tries a video mode to test it’s validity for deviceinfo.

Returns 1 on success.

voidfb_delete_videomode(const struct fb_videomode * mode, struct list_head * head)¶

removed videomode entry from modelist

Parameters

conststructfb_videomode*mode

videomode to remove

structlist_head*head

struct list_head of modelist

NOTES

Will remove all matching mode entries

intfb_find_mode(struct fb_var_screeninfo * var, struct fb_info * info, const char * mode_option, const struct fb_videomode * db, unsigned int dbsize, const struct fb_videomode * default_mode, unsigned int default_bpp)¶

finds a valid video mode

Parameters

structfb_var_screeninfo*var

frame buffer user defined part of display

structfb_info*info

frame buffer info structure

constchar*mode_option

string video mode to find

conststructfb_videomode*db

video mode database

unsignedintdbsize

size ofdb

conststructfb_videomode*default_mode

default video mode to fall back to

unsignedintdefault_bpp

default color depth in bits per pixel

Description

Finds a suitable video mode, starting with the specified modeinmode_option with fallback todefault_mode. Ifdefault_mode fails, all modes in the video mode database willbe tried.

Valid mode specifiers formode_option:

<xres>x<yres>[M][R][-<bpp>][@<refresh>][i][p][m]

or

<name>[-<bpp>][@<refresh>]

with <xres>, <yres>, <bpp> and <refresh> decimal numbers and<name> a string.

If ‘M’ is present after yres (and before refresh/bpp if present),the function will compute the timings using VESA(tm) CoordinatedVideo Timings (CVT). If ‘R’ is present after ‘M’, will compute withreduced blanking (for flatpanels). If ‘i’ or ‘p’ are present, computeinterlaced or progressive mode. If ‘m’ is present, add margins equalto 1.8% of xres rounded down to 8 pixels, and 1.8% of yres. The char‘i’, ‘p’ and ‘m’ must be after ‘M’ and ‘R’. Example:

1024x768MR-8@60m - Reduced blank with margins at 60Hz.

Returns zero for failure, 1 if using specifiedmode_option,2 if using specifiedmode_option with an ignored refresh rate,3 if default mode is used, 4 if fall back to any valid mode.

NOTE

The passed structvar is _not_ cleared! This allows youto supply values for e.g. the grayscale and accel_flags fields.

voidfb_var_to_videomode(struct fb_videomode * mode, const struct fb_var_screeninfo * var)¶

convert fb_var_screeninfo to fb_videomode

Parameters

structfb_videomode*mode

pointer to struct fb_videomode

conststructfb_var_screeninfo*var

pointer to struct fb_var_screeninfo

voidfb_videomode_to_var(struct fb_var_screeninfo * var, const struct fb_videomode * mode)¶

convert fb_videomode to fb_var_screeninfo

Parameters

structfb_var_screeninfo*var

pointer to struct fb_var_screeninfo

conststructfb_videomode*mode

pointer to struct fb_videomode

intfb_mode_is_equal(const struct fb_videomode * mode1, const struct fb_videomode * mode2)¶

compare 2 videomodes

Parameters

conststructfb_videomode*mode1

first videomode

conststructfb_videomode*mode2

second videomode

Return

1 if equal, 0 if not

const struct fb_videomode *fb_find_best_mode(const struct fb_var_screeninfo * var, struct list_head * head)¶

find best matching videomode

Parameters

conststructfb_var_screeninfo*var

pointer to struct fb_var_screeninfo

structlist_head*head

pointer to struct list_head of modelist

Return

struct fb_videomode, NULL if none found

Description

IMPORTANT:This function assumes that all modelist entries ininfo->modelist are valid.

NOTES

Finds best matching videomode which has an equal or greater dimension thanvar->xres and var->yres. If more than 1 videomode is found, will returnthe videomode with the highest refresh rate

const struct fb_videomode *fb_find_nearest_mode(const struct fb_videomode * mode, struct list_head * head)¶

find closest videomode

Parameters

conststructfb_videomode*mode

pointer to struct fb_videomode

structlist_head*head

pointer to modelist

Description

Finds best matching videomode, smaller or greater in dimension.If more than 1 videomode is found, will return the videomode withthe closest refresh rate.

const struct fb_videomode *fb_match_mode(const struct fb_var_screeninfo * var, struct list_head * head)¶

find a videomode which exactly matches the timings in var

Parameters

conststructfb_var_screeninfo*var

pointer to struct fb_var_screeninfo

structlist_head*head

pointer to struct list_head of modelist

Return

struct fb_videomode, NULL if none found

intfb_add_videomode(const struct fb_videomode * mode, struct list_head * head)¶

adds videomode entry to modelist

Parameters

conststructfb_videomode*mode

videomode to add

structlist_head*head

struct list_head of modelist

NOTES

Will only add unmatched mode entries

voidfb_destroy_modelist(struct list_head * head)¶

destroy modelist

Parameters

structlist_head*head

struct list_head of modelist

voidfb_videomode_to_modelist(const struct fb_videomode * modedb, int num, struct list_head * head)¶

convert mode array to mode list

Parameters

conststructfb_videomode*modedb

array of struct fb_videomode

intnum

number of entries in array

structlist_head*head

struct list_head of modelist

Frame Buffer Macintosh Video Mode Database¶

intmac_vmode_to_var(int vmode, int cmode, struct fb_var_screeninfo * var)¶

converts vmode/cmode pair to var structure

Parameters

intvmode

MacOS video mode

intcmode

MacOS color mode

structfb_var_screeninfo*var

frame buffer video mode structure

Converts a MacOS vmode/cmode pair to a frame buffer videomode structure.

Returns negative errno on error, or zero for success.

intmac_map_monitor_sense(int sense)¶

Convert monitor sense to vmode

Parameters

intsense

Macintosh monitor sense number

Converts a Macintosh monitor sense number to a MacOSvmode number.

Returns MacOS vmode video mode number.

intmac_find_mode(struct fb_var_screeninfo * var, struct fb_info * info, const char * mode_option, unsigned int default_bpp)¶

find a video mode

Parameters

structfb_var_screeninfo*var

frame buffer user defined part of display

structfb_info*info

frame buffer info structure

constchar*mode_option

video mode name (see mac_modedb[])

unsignedintdefault_bpp

default color depth in bits per pixel

Finds a suitable video mode. Tries to set mode specifiedbymode_option. If the name of the wanted mode begins with‘mac’, the Mac video mode database will be used, otherwise itwill fall back to the standard video mode database.

Note

Function marked as __init and can only be used during

system boot.

Returns error code from fb_find_mode (see fb_find_modefunction).

Frame Buffer Fonts¶

Refer to the file lib/fonts/fonts.c for more information.