sphinx.addnodesdocument)}( rawsourcechildren]( translations LanguagesNode)}(hhh](h pending_xref)}(hhh]docutils.nodesTextChinese (Simplified)}parenthsba attributes}(ids]classes]names]dupnames]backrefs] refdomainstdreftypedoc reftarget/translations/zh_CN/fb/fbconmodnameN classnameN refexplicitutagnamehhh ubh)}(hhh]hChinese (Traditional)}hh2sbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/zh_TW/fb/fbconmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hItalian}hhFsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/it_IT/fb/fbconmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hJapanese}hhZsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/ja_JP/fb/fbconmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hKorean}hhnsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/ko_KR/fb/fbconmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hSpanish}hhsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget/translations/sp_SP/fb/fbconmodnameN classnameN refexplicituh1hhh ubeh}(h]h ]h"]h$]h&]current_languageEnglishuh1h hh _documenthsourceNlineNubhsection)}(hhh](htitle)}(hThe Framebuffer Consoleh]hThe Framebuffer Console}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhh6/var/lib/git/docbuild/linux/Documentation/fb/fbcon.rsthKubh paragraph)}(hX#The framebuffer console (fbcon), as its name implies, is a text console running on top of the framebuffer device. It has the functionality of any standard text console driver, such as the VGA console, with the added features that can be attributed to the graphical nature of the framebuffer.h]hX#The framebuffer console (fbcon), as its name implies, is a text console running on top of the framebuffer device. It has the functionality of any standard text console driver, such as the VGA console, with the added features that can be attributed to the graphical nature of the framebuffer.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hIn the x86 architecture, the framebuffer console is optional, and some even treat it as a toy. For other architectures, it is the only available display device, text or graphical.h]hIn the x86 architecture, the framebuffer console is optional, and some even treat it as a toy. For other architectures, it is the only available display device, text or graphical.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK hhhhubh)}(hXWhat are the features of fbcon? The framebuffer console supports high resolutions, varying font types, display rotation, primitive multihead, etc. Theoretically, multi-colored fonts, blending, aliasing, and any feature made available by the underlying graphics card are also possible.h]hXWhat are the features of fbcon? The framebuffer console supports high resolutions, varying font types, display rotation, primitive multihead, etc. Theoretically, multi-colored fonts, blending, aliasing, and any feature made available by the underlying graphics card are also possible.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hhh](h)}(hA. Configurationh]hA. Configuration}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhhhhKubh)}(hX$The framebuffer console can be enabled by using your favorite kernel configuration tool. It is under Device Drivers->Graphics Support-> Console display driver support->Framebuffer Console Support. Select 'y' to compile support statically or 'm' for module support. The module will be fbcon.h]hX,The framebuffer console can be enabled by using your favorite kernel configuration tool. It is under Device Drivers->Graphics Support-> Console display driver support->Framebuffer Console Support. Select ‘y’ to compile support statically or ‘m’ for module support. The module will be fbcon.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hXuIn order for fbcon to activate, at least one framebuffer driver is required, so choose from any of the numerous drivers available. For x86 systems, they almost universally have VGA cards, so vga16fb and vesafb will always be available. However, using a chipset-specific driver will give you more speed and features, such as the ability to change the video mode dynamically.h]hXuIn order for fbcon to activate, at least one framebuffer driver is required, so choose from any of the numerous drivers available. For x86 systems, they almost universally have VGA cards, so vga16fb and vesafb will always be available. However, using a chipset-specific driver will give you more speed and features, such as the ability to change the video mode dynamically.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hXTo display the penguin logo, choose any logo available in Graphics support->Bootup logo.h]hXTo display the penguin logo, choose any logo available in Graphics support->Bootup logo.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK#hhhhubh)}(hAlso, you will need to select at least one compiled-in font, but if you don't do anything, the kernel configuration tool will select one for you, usually an 8x16 font.h]hAlso, you will need to select at least one compiled-in font, but if you don’t do anything, the kernel configuration tool will select one for you, usually an 8x16 font.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK&hhhhubh)}(hXDGOTCHA: A common bug report is enabling the framebuffer without enabling the framebuffer console. Depending on the driver, you may get a blanked or garbled display, but the system still boots to completion. If you are fortunate to have a driver that does not alter the graphics chip, then you will still get a VGA console.h]hXDGOTCHA: A common bug report is enabling the framebuffer without enabling the framebuffer console. Depending on the driver, you may get a blanked or garbled display, but the system still boots to completion. If you are fortunate to have a driver that does not alter the graphics chip, then you will still get a VGA console.}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK*hhhhubeh}(h]a-configurationah ]h"]a. configurationah$]h&]uh1hhhhhhhhKubh)}(hhh](h)}(h B. Loadingh]h B. Loading}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjBhhhhhK1ubh)}(hPossible scenarios:h]hPossible scenarios:}(hjShhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK3hjBhhubhenumerated_list)}(hhh](h list_item)}(hDriver and fbcon are compiled statically Usually, fbcon will automatically take over your console. The notable exception is vesafb. It needs to be explicitly activated with the vga= boot option parameter. h](h)}(h(Driver and fbcon are compiled staticallyh]h(Driver and fbcon are compiled statically}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK5hjhubh block_quote)}(hUsually, fbcon will automatically take over your console. The notable exception is vesafb. It needs to be explicitly activated with the vga= boot option parameter. h]h)}(hUsually, fbcon will automatically take over your console. The notable exception is vesafb. It needs to be explicitly activated with the vga= boot option parameter.h]hUsually, fbcon will automatically take over your console. The notable exception is vesafb. It needs to be explicitly activated with the vga= boot option parameter.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK7hj|ubah}(h]h ]h"]h$]h&]uh1jzhhhK7hjhubeh}(h]h ]h"]h$]h&]uh1jfhjchhhhhNubjg)}(hDriver is compiled statically, fbcon is compiled as a module Depending on the driver, you either get a standard console, or a garbled display, as mentioned above. To get a framebuffer console, do a 'modprobe fbcon'. h](h)}(h Select the initial font to use. The value 'name' can be any of the compiled-in fonts: 10x18, 6x10, 6x8, 7x14, Acorn8x8, MINI4x6, PEARL8x8, ProFont6x11, SUN12x22, SUN8x16, TER16x32, VGA8x16, VGA8x8. Note, not all drivers can handle font with widths not divisible by 8, such as vga16fb. h](h)}(hfbcon=font:h]hfbcon=font:}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKQhjsubj{)}(hXSelect the initial font to use. The value 'name' can be any of the compiled-in fonts: 10x18, 6x10, 6x8, 7x14, Acorn8x8, MINI4x6, PEARL8x8, ProFont6x11, SUN12x22, SUN8x16, TER16x32, VGA8x16, VGA8x8. Note, not all drivers can handle font with widths not divisible by 8, such as vga16fb. h](h)}(hSelect the initial font to use. The value 'name' can be any of the compiled-in fonts: 10x18, 6x10, 6x8, 7x14, Acorn8x8, MINI4x6, PEARL8x8, ProFont6x11, SUN12x22, SUN8x16, TER16x32, VGA8x16, VGA8x8.h]hSelect the initial font to use. The value ‘name’ can be any of the compiled-in fonts: 10x18, 6x10, 6x8, 7x14, Acorn8x8, MINI4x6, PEARL8x8, ProFont6x11, SUN12x22, SUN8x16, TER16x32, VGA8x16, VGA8x8.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKShjubh)}(hVNote, not all drivers can handle font with widths not divisible by 8, such as vga16fb.h]hVNote, not all drivers can handle font with widths not divisible by 8, such as vga16fb.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKWhjubeh}(h]h ]h"]h$]h&]uh1jzhhhKShjsubeh}(h]h ]h"]h$]h&]uh1jfhjphhhhhNubjg)}(hXGfbcon=map:<0123> This is an interesting option. It tells which driver gets mapped to which console. The value '0123' is a sequence that gets repeated until the total length is 64 which is the number of consoles available. In the above example, it is expanded to 012301230123... and the mapping will be:: tty | 1 2 3 4 5 6 7 8 9 ... fb | 0 1 2 3 0 1 2 3 0 ... ('cat /proc/fb' should tell you what the fb numbers are) One side effect that may be useful is using a map value that exceeds the number of loaded fb drivers. For example, if only one driver is available, fb0, adding fbcon=map:1 tells fbcon not to take over the console. Later on, when you want to map the console the to the framebuffer device, you can use the con2fbmap utility. h](h)}(hfbcon=map:<0123>h]hfbcon=map:<0123>}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK[hjubj{)}(hXThis is an interesting option. It tells which driver gets mapped to which console. The value '0123' is a sequence that gets repeated until the total length is 64 which is the number of consoles available. In the above example, it is expanded to 012301230123... and the mapping will be:: tty | 1 2 3 4 5 6 7 8 9 ... fb | 0 1 2 3 0 1 2 3 0 ... ('cat /proc/fb' should tell you what the fb numbers are) One side effect that may be useful is using a map value that exceeds the number of loaded fb drivers. For example, if only one driver is available, fb0, adding fbcon=map:1 tells fbcon not to take over the console. Later on, when you want to map the console the to the framebuffer device, you can use the con2fbmap utility. h](h)}(hXThis is an interesting option. It tells which driver gets mapped to which console. The value '0123' is a sequence that gets repeated until the total length is 64 which is the number of consoles available. In the above example, it is expanded to 012301230123... and the mapping will be::h]hX!This is an interesting option. It tells which driver gets mapped to which console. The value ‘0123’ is a sequence that gets repeated until the total length is 64 which is the number of consoles available. In the above example, it is expanded to 012301230123... and the mapping will be:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK]hjubh literal_block)}(hqtty | 1 2 3 4 5 6 7 8 9 ... fb | 0 1 2 3 0 1 2 3 0 ... ('cat /proc/fb' should tell you what the fb numbers are)h]hqtty | 1 2 3 4 5 6 7 8 9 ... fb | 0 1 2 3 0 1 2 3 0 ... ('cat /proc/fb' should tell you what the fb numbers are)}hjsbah}(h]h ]h"]h$]h&] xml:spacepreserveuh1jhhhKchjubh)}(hOne side effect that may be useful is using a map value that exceeds the number of loaded fb drivers. For example, if only one driver is available, fb0, adding fbcon=map:1 tells fbcon not to take over the console.h]hOne side effect that may be useful is using a map value that exceeds the number of loaded fb drivers. For example, if only one driver is available, fb0, adding fbcon=map:1 tells fbcon not to take over the console.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhjubh)}(hlLater on, when you want to map the console the to the framebuffer device, you can use the con2fbmap utility.h]hlLater on, when you want to map the console the to the framebuffer device, you can use the con2fbmap utility.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKmhjubeh}(h]h ]h"]h$]h&]uh1jzhhhK]hjubeh}(h]h ]h"]h$]h&]uh1jfhjphhhhhNubjg)}(hXfbcon=vc:- This option tells fbcon to take over only a range of consoles as specified by the values 'n1' and 'n2'. The rest of the consoles outside the given range will still be controlled by the standard console driver. NOTE: For x86 machines, the standard console is the VGA console which is typically located on the same video card. Thus, the consoles that are controlled by the VGA console will be garbled. h](h)}(hfbcon=vc:-h]hfbcon=vc:-}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKphjubj{)}(hXThis option tells fbcon to take over only a range of consoles as specified by the values 'n1' and 'n2'. The rest of the consoles outside the given range will still be controlled by the standard console driver. NOTE: For x86 machines, the standard console is the VGA console which is typically located on the same video card. Thus, the consoles that are controlled by the VGA console will be garbled. h](h)}(hThis option tells fbcon to take over only a range of consoles as specified by the values 'n1' and 'n2'. The rest of the consoles outside the given range will still be controlled by the standard console driver.h]hThis option tells fbcon to take over only a range of consoles as specified by the values ‘n1’ and ‘n2’. The rest of the consoles outside the given range will still be controlled by the standard console driver.}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKrhj!ubh)}(hNOTE: For x86 machines, the standard console is the VGA console which is typically located on the same video card. Thus, the consoles that are controlled by the VGA console will be garbled.h]hNOTE: For x86 machines, the standard console is the VGA console which is typically located on the same video card. Thus, the consoles that are controlled by the VGA console will be garbled.}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKwhj!ubeh}(h]h ]h"]h$]h&]uh1jzhhhKrhjubeh}(h]h ]h"]h$]h&]uh1jfhjphhhhhNubjg)}(hXfbcon=rotate: This option changes the orientation angle of the console display. The value 'n' accepts the following: - 0 - normal orientation (0 degree) - 1 - clockwise orientation (90 degrees) - 2 - upside down orientation (180 degrees) - 3 - counterclockwise orientation (270 degrees) The angle can be changed anytime afterwards by 'echoing' the same numbers to any one of the 2 attributes found in /sys/class/graphics/fbcon: - rotate - rotate the display of the active console - rotate_all - rotate the display of all consoles Console rotation will only become available if Framebuffer Console Rotation support is compiled in your kernel. NOTE: This is purely console rotation. Any other applications that use the framebuffer will remain at their 'normal' orientation. Actually, the underlying fb driver is totally ignorant of console rotation. h](h)}(hfbcon=rotate:h]hfbcon=rotate:}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK{hjMubj{)}(hXlThis option changes the orientation angle of the console display. The value 'n' accepts the following: - 0 - normal orientation (0 degree) - 1 - clockwise orientation (90 degrees) - 2 - upside down orientation (180 degrees) - 3 - counterclockwise orientation (270 degrees) The angle can be changed anytime afterwards by 'echoing' the same numbers to any one of the 2 attributes found in /sys/class/graphics/fbcon: - rotate - rotate the display of the active console - rotate_all - rotate the display of all consoles Console rotation will only become available if Framebuffer Console Rotation support is compiled in your kernel. NOTE: This is purely console rotation. Any other applications that use the framebuffer will remain at their 'normal' orientation. Actually, the underlying fb driver is totally ignorant of console rotation. h](h)}(hfThis option changes the orientation angle of the console display. The value 'n' accepts the following:h]hjThis option changes the orientation angle of the console display. The value ‘n’ accepts the following:}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK}hj_ubj{)}(h- 0 - normal orientation (0 degree) - 1 - clockwise orientation (90 degrees) - 2 - upside down orientation (180 degrees) - 3 - counterclockwise orientation (270 degrees) h]h bullet_list)}(hhh](jg)}(h!0 - normal orientation (0 degree)h]h)}(hj|h]h!0 - normal orientation (0 degree)}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjzubah}(h]h ]h"]h$]h&]uh1jfhjwubjg)}(h&1 - clockwise orientation (90 degrees)h]h)}(hjh]h&1 - clockwise orientation (90 degrees)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jfhjwubjg)}(h)2 - upside down orientation (180 degrees)h]h)}(hjh]h)2 - upside down orientation (180 degrees)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jfhjwubjg)}(h/3 - counterclockwise orientation (270 degrees) h]h)}(h.3 - counterclockwise orientation (270 degrees)h]h.3 - counterclockwise orientation (270 degrees)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jfhjwubeh}(h]h ]h"]h$]h&]bullet-uh1juhhhKhjqubah}(h]h ]h"]h$]h&]uh1jzhhhKhj_ubh)}(hThe angle can be changed anytime afterwards by 'echoing' the same numbers to any one of the 2 attributes found in /sys/class/graphics/fbcon:h]hThe angle can be changed anytime afterwards by ‘echoing’ the same numbers to any one of the 2 attributes found in /sys/class/graphics/fbcon:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj_ubj{)}(hj- rotate - rotate the display of the active console - rotate_all - rotate the display of all consoles h]jv)}(hhh](jg)}(h5rotate - rotate the display of the active consoleh]h)}(hjh]h5rotate - rotate the display of the active console}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jfhjubjg)}(h0rotate_all - rotate the display of all consoles h]h)}(h/rotate_all - rotate the display of all consolesh]h/rotate_all - rotate the display of all consoles}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jfhjubeh}(h]h ]h"]h$]h&]jjuh1juhhhKhjubah}(h]h ]h"]h$]h&]uh1jzhhhKhj_ubh)}(hoConsole rotation will only become available if Framebuffer Console Rotation support is compiled in your kernel.h]hoConsole rotation will only become available if Framebuffer Console Rotation support is compiled in your kernel.}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj_ubh)}(hNOTE: This is purely console rotation. Any other applications that use the framebuffer will remain at their 'normal' orientation. Actually, the underlying fb driver is totally ignorant of console rotation.h]hNOTE: This is purely console rotation. Any other applications that use the framebuffer will remain at their ‘normal’ orientation. Actually, the underlying fb driver is totally ignorant of console rotation.}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj_ubeh}(h]h ]h"]h$]h&]uh1jzhhhK}hjMubeh}(h]h ]h"]h$]h&]uh1jfhjphhhhhNubjg)}(hX@fbcon=margin: This option specifies the color of the margins. The margins are the leftover area at the right and the bottom of the screen that are not used by text. By default, this area will be black. The 'color' value is an integer number that depends on the framebuffer driver being used. h](h)}(hfbcon=margin:h]hfbcon=margin:}(hjahhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj]ubj{)}(hXThis option specifies the color of the margins. The margins are the leftover area at the right and the bottom of the screen that are not used by text. By default, this area will be black. The 'color' value is an integer number that depends on the framebuffer driver being used. h]h)}(hXThis option specifies the color of the margins. The margins are the leftover area at the right and the bottom of the screen that are not used by text. By default, this area will be black. The 'color' value is an integer number that depends on the framebuffer driver being used.h]hXThis option specifies the color of the margins. The margins are the leftover area at the right and the bottom of the screen that are not used by text. By default, this area will be black. The ‘color’ value is an integer number that depends on the framebuffer driver being used.}(hjshhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjoubah}(h]h ]h"]h$]h&]uh1jzhhhKhj]ubeh}(h]h ]h"]h$]h&]uh1jfhjphhhhhNubjg)}(hX@fbcon=nodefer If the kernel is compiled with deferred fbcon takeover support, normally the framebuffer contents, left in place by the firmware/bootloader, will be preserved until there actually is some text is output to the console. This option causes fbcon to bind immediately to the fbdev device. h](h)}(h fbcon=nodeferh]h fbcon=nodefer}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubj{)}(hXIf the kernel is compiled with deferred fbcon takeover support, normally the framebuffer contents, left in place by the firmware/bootloader, will be preserved until there actually is some text is output to the console. This option causes fbcon to bind immediately to the fbdev device. h]h)}(hXIf the kernel is compiled with deferred fbcon takeover support, normally the framebuffer contents, left in place by the firmware/bootloader, will be preserved until there actually is some text is output to the console. This option causes fbcon to bind immediately to the fbdev device.h]hXIf the kernel is compiled with deferred fbcon takeover support, normally the framebuffer contents, left in place by the firmware/bootloader, will be preserved until there actually is some text is output to the console. This option causes fbcon to bind immediately to the fbdev device.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jzhhhKhjubeh}(h]h ]h"]h$]h&]uh1jfhjphhhhhNubjg)}(hXNfbcon=logo-pos: The only possible 'location' is 'center' (without quotes), and when given, the bootup logo is moved from the default top-left corner location to the center of the framebuffer. If more than one logo is displayed due to multiple CPUs, the collected line of logos is moved as a whole. h](h)}(hfbcon=logo-pos:h]hfbcon=logo-pos:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubj{)}(hXThe only possible 'location' is 'center' (without quotes), and when given, the bootup logo is moved from the default top-left corner location to the center of the framebuffer. If more than one logo is displayed due to multiple CPUs, the collected line of logos is moved as a whole. h]h)}(hXThe only possible 'location' is 'center' (without quotes), and when given, the bootup logo is moved from the default top-left corner location to the center of the framebuffer. If more than one logo is displayed due to multiple CPUs, the collected line of logos is moved as a whole.h]hX!The only possible ‘location’ is ‘center’ (without quotes), and when given, the bootup logo is moved from the default top-left corner location to the center of the framebuffer. If more than one logo is displayed due to multiple CPUs, the collected line of logos is moved as a whole.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jzhhhKhjubeh}(h]h ]h"]h$]h&]uh1jfhjphhhhhNubjg)}(hfbcon=logo-count: The value 'n' overrides the number of bootup logos. 0 disables the logo, and -1 gives the default which is the number of online CPUs. h](h)}(hfbcon=logo-count:h]hfbcon=logo-count:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubj{)}(hThe value 'n' overrides the number of bootup logos. 0 disables the logo, and -1 gives the default which is the number of online CPUs. h]h)}(hThe value 'n' overrides the number of bootup logos. 0 disables the logo, and -1 gives the default which is the number of online CPUs.h]hThe value ‘n’ overrides the number of bootup logos. 0 disables the logo, and -1 gives the default which is the number of online CPUs.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jzhhhKhjubeh}(h]h ]h"]h$]h&]uh1jfhjphhhhhNubeh}(h]h ]h"]h$]h&]j0j1j2hj3j4uh1jahjBhhhhhKQubjb)}(hhh]jg)}(h#Attaching, Detaching and Unloading h]h)}(h"Attaching, Detaching and Unloadingh]h"Attaching, Detaching and Unloading}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj&ubah}(h]h ]h"]h$]h&]uh1jfhj#hhhhhNubah}(h]h ]h"]h$]h&]j0jnj2hj3j4joKuh1jahjBhhhhhKubh)}(hzBefore going on to how to attach, detach and unload the framebuffer console, an illustration of the dependencies may help.h]hzBefore going on to how to attach, detach and unload the framebuffer console, an illustration of the dependencies may help.}(hjDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubh)}(hvThe console layer, as with most subsystems, needs a driver that interfaces with the hardware. Thus, in a VGA console::h]huThe console layer, as with most subsystems, needs a driver that interfaces with the hardware. Thus, in a VGA console:}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubj)}(h&console ---> VGA driver ---> hardware.h]h&console ---> VGA driver ---> hardware.}hj`sbah}(h]h ]h"]h$]h&]jjuh1jhhhKhjBhhubh)}(hXAssuming the VGA driver can be unloaded, one must first unbind the VGA driver from the console layer before unloading the driver. The VGA driver cannot be unloaded if it is still bound to the console layer. (See Documentation/driver-api/console.rst for more information).h]hXAssuming the VGA driver can be unloaded, one must first unbind the VGA driver from the console layer before unloading the driver. The VGA driver cannot be unloaded if it is still bound to the console layer. (See Documentation/driver-api/console.rst for more information).}(hjnhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubh)}(hThis is more complicated in the case of the framebuffer console (fbcon), because fbcon is an intermediate layer between the console and the drivers::h]hThis is more complicated in the case of the framebuffer console (fbcon), because fbcon is an intermediate layer between the console and the drivers:}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubj)}(h3console ---> fbcon ---> fbdev drivers ---> hardwareh]h3console ---> fbcon ---> fbdev drivers ---> hardware}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhKhjBhhubh)}(hxThe fbdev drivers cannot be unloaded if bound to fbcon, and fbcon cannot be unloaded if it's bound to the console layer.h]hzThe fbdev drivers cannot be unloaded if bound to fbcon, and fbcon cannot be unloaded if it’s bound to the console layer.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubh)}(hX0So to unload the fbdev drivers, one must first unbind fbcon from the console, then unbind the fbdev drivers from fbcon. Fortunately, unbinding fbcon from the console layer will automatically unbind framebuffer drivers from fbcon. Thus, there is no need to explicitly unbind the fbdev drivers from fbcon.h]hX0So to unload the fbdev drivers, one must first unbind fbcon from the console, then unbind the fbdev drivers from fbcon. Fortunately, unbinding fbcon from the console layer will automatically unbind framebuffer drivers from fbcon. Thus, there is no need to explicitly unbind the fbdev drivers from fbcon.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubh)}(hySo, how do we unbind fbcon from the console? Part of the answer is in Documentation/driver-api/console.rst. To summarize:h]hySo, how do we unbind fbcon from the console? Part of the answer is in Documentation/driver-api/console.rst. To summarize:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubh)}(hyEcho a value to the bind file that represents the framebuffer console driver. So assuming vtcon1 represents fbcon, then::h]hxEcho a value to the bind file that represents the framebuffer console driver. So assuming vtcon1 represents fbcon, then:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubj)}(hXecho 1 > /sys/class/vtconsole/vtcon1/bind - attach framebuffer console to console layer echo 0 > /sys/class/vtconsole/vtcon1/bind - detach framebuffer console from console layerh]hXecho 1 > /sys/class/vtconsole/vtcon1/bind - attach framebuffer console to console layer echo 0 > /sys/class/vtconsole/vtcon1/bind - detach framebuffer console from console layer}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhKhjBhhubh)}(hXIf fbcon is detached from the console layer, your boot console driver (which is usually VGA text mode) will take over. A few drivers (rivafb and i810fb) will restore VGA text mode for you. With the rest, before detaching fbcon, you must take a few additional steps to make sure that your VGA text mode is restored properly. The following is one of the several methods that you can do:h]hXIf fbcon is detached from the console layer, your boot console driver (which is usually VGA text mode) will take over. A few drivers (rivafb and i810fb) will restore VGA text mode for you. With the rest, before detaching fbcon, you must take a few additional steps to make sure that your VGA text mode is restored properly. The following is one of the several methods that you can do:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubjb)}(hhh](jg)}(hDownload or install vbetool. This utility is included with most distributions nowadays, and is usually part of the suspend/resume tool. h]h)}(hDownload or install vbetool. This utility is included with most distributions nowadays, and is usually part of the suspend/resume tool.h]hDownload or install vbetool. This utility is included with most distributions nowadays, and is usually part of the suspend/resume tool.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jfhjhhhhhNubjg)}(hIn your kernel configuration, ensure that CONFIG_FRAMEBUFFER_CONSOLE is set to 'y' or 'm'. Enable one or more of your favorite framebuffer drivers. h]h)}(hIn your kernel configuration, ensure that CONFIG_FRAMEBUFFER_CONSOLE is set to 'y' or 'm'. Enable one or more of your favorite framebuffer drivers.h]hIn your kernel configuration, ensure that CONFIG_FRAMEBUFFER_CONSOLE is set to ‘y’ or ‘m’. Enable one or more of your favorite framebuffer drivers.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jfhjhhhhhNubjg)}(hBoot into text mode and as root run:: vbetool vbestate save > The above command saves the register contents of your graphics hardware to . You need to do this step only once as the state file can be reused. h](h)}(h%Boot into text mode and as root run::h]h$Boot into text mode and as root run:}(hj#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubj)}(h(vbetool vbestate save > h]h(vbetool vbestate save > }hj1sbah}(h]h ]h"]h$]h&]jjuh1jhhhKhjubh)}(hThe above command saves the register contents of your graphics hardware to . You need to do this step only once as the state file can be reused.h]hThe above command saves the register contents of your graphics hardware to . You need to do this step only once as the state file can be reused.}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubeh}(h]h ]h"]h$]h&]uh1jfhjhhhhhNubjg)}(hLIf fbcon is compiled as a module, load fbcon by doing:: modprobe fbcon h](h)}(h7If fbcon is compiled as a module, load fbcon by doing::h]h6If fbcon is compiled as a module, load fbcon by doing:}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjSubj)}(hmodprobe fbconh]hmodprobe fbcon}hjesbah}(h]h ]h"]h$]h&]jjuh1jhhhKhjSubeh}(h]h ]h"]h$]h&]uh1jfhjhhhhhNubjg)}(hzNow to detach fbcon:: vbetool vbestate restore < && \ echo 0 > /sys/class/vtconsole/vtcon1/bind h](h)}(hNow to detach fbcon::h]hNow to detach fbcon:}(hj}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjyubj)}(hZvbetool vbestate restore < && \ echo 0 > /sys/class/vtconsole/vtcon1/bindh]hZvbetool vbestate restore < && \ echo 0 > /sys/class/vtconsole/vtcon1/bind}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhKhjyubeh}(h]h ]h"]h$]h&]uh1jfhjhhhhhNubjg)}(hoThat's it, you're back to VGA mode. And if you compiled fbcon as a module, you can unload it by 'rmmod fbcon'. h]h)}(hnThat's it, you're back to VGA mode. And if you compiled fbcon as a module, you can unload it by 'rmmod fbcon'.h]hvThat’s it, you’re back to VGA mode. And if you compiled fbcon as a module, you can unload it by ‘rmmod fbcon’.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jfhjhhhhhNubjg)}(hCTo reattach fbcon:: echo 1 > /sys/class/vtconsole/vtcon1/bind h](h)}(hTo reattach fbcon::h]hTo reattach fbcon:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubj)}(h)echo 1 > /sys/class/vtconsole/vtcon1/bindh]h)echo 1 > /sys/class/vtconsole/vtcon1/bind}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhKhjubeh}(h]h ]h"]h$]h&]uh1jfhjhhhhhNubeh}(h]h ]h"]h$]h&]j0j1j2hj3j4uh1jahjBhhhhhKubh)}(hX8. Once fbcon is unbound, all drivers registered to the system will also become unbound. This means that fbcon and individual framebuffer drivers can be unloaded or reloaded at will. Reloading the drivers or fbcon will automatically bind the console, fbcon and the drivers together. Unloading all the drivers without unloading fbcon will make it impossible for the console to bind fbcon.h]hX8. Once fbcon is unbound, all drivers registered to the system will also become unbound. This means that fbcon and individual framebuffer drivers can be unloaded or reloaded at will. Reloading the drivers or fbcon will automatically bind the console, fbcon and the drivers together. Unloading all the drivers without unloading fbcon will make it impossible for the console to bind fbcon.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjBhhubeh}(h] b-loadingah ]h"] b. loadingah$]h&]uh1hhhhhhhhK1ubh)}(hhh](h)}(hNotes for vesafb users:h]hNotes for vesafb users:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhhhMubh)}(hXUnfortunately, if your bootline includes a vga=xxx parameter that sets the hardware in graphics mode, such as when loading vesafb, vgacon will not load. Instead, vgacon will replace the default boot console with dummycon, and you won't get any display after detaching fbcon. Your machine is still alive, so you can reattach vesafb. However, to reattach vesafb, you need to do one of the following:h]hXUnfortunately, if your bootline includes a vga=xxx parameter that sets the hardware in graphics mode, such as when loading vesafb, vgacon will not load. Instead, vgacon will replace the default boot console with dummycon, and you won’t get any display after detaching fbcon. Your machine is still alive, so you can reattach vesafb. However, to reattach vesafb, you need to do one of the following:}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjhhubh)}(h Variation 1:h]h Variation 1:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hjhhubj{)}(hXKa. Before detaching fbcon, do:: vbetool vbemode save > # do once for each vesafb mode, # the file can be reused b. Detach fbcon as in step 5. c. Attach fbcon:: vbetool vbestate restore < && \ echo 1 > /sys/class/vtconsole/vtcon1/bind h]jb)}(hhh](jg)}(hBefore detaching fbcon, do:: vbetool vbemode save > # do once for each vesafb mode, # the file can be reused h](h)}(hBefore detaching fbcon, do::h]hBefore detaching fbcon, do:}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubj)}(hvbetool vbemode save > # do once for each vesafb mode, # the file can be reusedh]hvbetool vbemode save > # do once for each vesafb mode, # the file can be reused}hj?sbah}(h]h ]h"]h$]h&]jjuh1jhhhMhj-ubeh}(h]h ]h"]h$]h&]uh1jfhj*ubjg)}(hDetach fbcon as in step 5. h]h)}(hDetach fbcon as in step 5.h]hDetach fbcon as in step 5.}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjSubah}(h]h ]h"]h$]h&]uh1jfhj*ubjg)}(hnAttach fbcon:: vbetool vbestate restore < && \ echo 1 > /sys/class/vtconsole/vtcon1/bind h](h)}(hAttach fbcon::h]h Attach fbcon:}(hjohhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjkubj)}(h[vbetool vbestate restore < && \ echo 1 > /sys/class/vtconsole/vtcon1/bindh]h[vbetool vbestate restore < && \ echo 1 > /sys/class/vtconsole/vtcon1/bind}hj}sbah}(h]h ]h"]h$]h&]jjuh1jhhhMhjkubeh}(h]h ]h"]h$]h&]uh1jfhj*ubeh}(h]h ]h"]h$]h&]j0 loweralphaj2hj3j4uh1jahj&ubah}(h]h ]h"]h$]h&]uh1jzhhhMhjhhubh)}(h Variation 2:h]h Variation 2:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjhhubj{)}(hXa. Before detaching fbcon, do:: echo > /sys/class/tty/console/bind vbetool vbemode get b. Take note of the mode number b. Detach fbcon as in step 5. c. Attach fbcon:: vbetool vbemode set && \ echo 1 > /sys/class/vtconsole/vtcon1/bind h](jb)}(hhh](jg)}(h]Before detaching fbcon, do:: echo > /sys/class/tty/console/bind vbetool vbemode get h](h)}(hBefore detaching fbcon, do::h]hBefore detaching fbcon, do:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubj)}(h > /sys/class/tty/console/bind vbetool vbemode geth]h > /sys/class/tty/console/bind vbetool vbemode get}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhMhjubeh}(h]h ]h"]h$]h&]uh1jfhjubjg)}(hTake note of the mode number h]h)}(hTake note of the mode numberh]hTake note of the mode number}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM"hjubah}(h]h ]h"]h$]h&]uh1jfhjubeh}(h]h ]h"]h$]h&]j0jj2hj3j4uh1jahjubjb)}(hhh](jg)}(hDetach fbcon as in step 5. h]h)}(hDetach fbcon as in step 5.h]hDetach fbcon as in step 5.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM$hjubah}(h]h ]h"]h$]h&]uh1jfhjubjg)}(hcAttach fbcon:: vbetool vbemode set && \ echo 1 > /sys/class/vtconsole/vtcon1/bind h](h)}(hAttach fbcon::h]h Attach fbcon:}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM&hjubj)}(hPvbetool vbemode set && \ echo 1 > /sys/class/vtconsole/vtcon1/bindh]hPvbetool vbemode set && \ echo 1 > /sys/class/vtconsole/vtcon1/bind}hj$sbah}(h]h ]h"]h$]h&]jjuh1jhhhM(hjubeh}(h]h ]h"]h$]h&]uh1jfhjubeh}(h]h ]h"]h$]h&]j0jj2hj3j4joKuh1jahjubeh}(h]h ]h"]h$]h&]uh1jzhhhMhjhhubeh}(h]notes-for-vesafb-usersah ]h"]notes for vesafb users:ah$]h&]uh1hhhhhhhhMubh)}(hhh](h)}(hSamples:h]hSamples:}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjLhhhhhM,ubh)}(h{Here are 2 sample bash scripts that you can use to bind or unbind the framebuffer console driver if you are on an X86 box::h]hzHere are 2 sample bash scripts that you can use to bind or unbind the framebuffer console driver if you are on an X86 box:}(hj]hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM.hjLhhubj)}(hXl#!/bin/bash # Unbind fbcon # Change this to where your actual vgastate file is located # Or Use VGASTATE=$1 to indicate the state file at runtime VGASTATE=/tmp/vgastate # path to vbetool VBETOOL=/usr/local/bin for (( i = 0; i < 16; i++)) do if test -x /sys/class/vtconsole/vtcon$i; then if [ `cat /sys/class/vtconsole/vtcon$i/name | grep -c "frame buffer"` \ = 1 ]; then if test -x $VBETOOL/vbetool; then echo Unbinding vtcon$i $VBETOOL/vbetool vbestate restore < $VGASTATE echo 0 > /sys/class/vtconsole/vtcon$i/bind fi fi fi doneh]hXl#!/bin/bash # Unbind fbcon # Change this to where your actual vgastate file is located # Or Use VGASTATE=$1 to indicate the state file at runtime VGASTATE=/tmp/vgastate # path to vbetool VBETOOL=/usr/local/bin for (( i = 0; i < 16; i++)) do if test -x /sys/class/vtconsole/vtcon$i; then if [ `cat /sys/class/vtconsole/vtcon$i/name | grep -c "frame buffer"` \ = 1 ]; then if test -x $VBETOOL/vbetool; then echo Unbinding vtcon$i $VBETOOL/vbetool vbestate restore < $VGASTATE echo 0 > /sys/class/vtconsole/vtcon$i/bind fi fi fi done}hjksbah}(h]h ]h"]h$]h&]jjuh1jhhhM1hjLhhubh transition)}(hK---------------------------------------------------------------------------h]h}(h]h ]h"]h$]h&]uh1jyhhhMJhjLhhubj)}(hX2#!/bin/bash # Bind fbcon for (( i = 0; i < 16; i++)) do if test -x /sys/class/vtconsole/vtcon$i; then if [ `cat /sys/class/vtconsole/vtcon$i/name | grep -c "frame buffer"` \ = 1 ]; then echo Unbinding vtcon$i echo 1 > /sys/class/vtconsole/vtcon$i/bind fi fi doneh]hX2#!/bin/bash # Bind fbcon for (( i = 0; i < 16; i++)) do if test -x /sys/class/vtconsole/vtcon$i; then if [ `cat /sys/class/vtconsole/vtcon$i/name | grep -c "frame buffer"` \ = 1 ]; then echo Unbinding vtcon$i echo 1 > /sys/class/vtconsole/vtcon$i/bind fi fi done}hjsbah}(h]h ]h"]h$]h&]jjuh1jhhhMNhjLhhubh)}(h!Antonino Daplas h](hAntonino Daplas <}(hjhhhNhNubh reference)}(hadaplas@pol.neth]hadaplas@pol.net}(hjhhhNhNubah}(h]h ]h"]h$]h&]refurimailto:adaplas@pol.netuh1jhjubh>}(hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhM\hjLhhubeh}(h]samplesah ]h"]samples:ah$]h&]uh1hhhhhhhhM,ubeh}(h]the-framebuffer-consoleah ]h"]the framebuffer consoleah$]h&]uh1hhhhhhhhKubeh}(h]h ]h"]h$]h&]sourcehuh1hcurrent_sourceN current_lineNsettingsdocutils.frontendValues)}(hN generatorN datestampN source_linkN source_urlN toc_backlinksentryfootnote_backlinksK sectnum_xformKstrip_commentsNstrip_elements_with_classesN strip_classesN report_levelK halt_levelKexit_status_levelKdebugNwarning_streamN tracebackinput_encoding utf-8-siginput_encoding_error_handlerstrictoutput_encodingutf-8output_encoding_error_handlerjerror_encodingutf-8error_encoding_error_handlerbackslashreplace language_codeenrecord_dependenciesNconfigN id_prefixhauto_id_prefixid dump_settingsNdump_internalsNdump_transformsNdump_pseudo_xmlNexpose_internalsNstrict_visitorN_disable_configN_sourceh _destinationN _config_files]7/var/lib/git/docbuild/linux/Documentation/docutils.confafile_insertion_enabled raw_enabledKline_length_limitM'pep_referencesN pep_base_urlhttps://peps.python.org/pep_file_url_templatepep-%04drfc_referencesN rfc_base_url&https://datatracker.ietf.org/doc/html/ tab_widthKtrim_footnote_reference_spacesyntax_highlightlong smart_quotessmartquotes_locales]character_level_inline_markupdoctitle_xform docinfo_xformKsectsubtitle_xform image_loadinglinkembed_stylesheetcloak_email_addressessection_self_linkenvNubreporterNindirect_targets]substitution_defs}substitution_names}refnames}refids}nameids}(jjj?j<jjjIjFjju nametypes}(jj?jjIjuh}(jhj<hjjBjFjjjLu footnote_refs} citation_refs} autofootnotes]autofootnote_refs]symbol_footnotes]symbol_footnote_refs] footnotes] citations]autofootnote_startKsymbol_footnote_startK id_counter collectionsCounter}Rparse_messages](hsystem_message)}(hhh]h)}(h:Enumerated list start value not ordinal-1: "C" (ordinal 3)h]h>Enumerated list start value not ordinal-1: “C” (ordinal 3)}(hjQ hhhNhNubah}(h]h ]h"]h$]h&]uh1hhjN ubah}(h]h ]h"]h$]h&]levelKtypeINFOsourcehlineKuh1jL hjBhhhhhKLubjM )}(hhh]h)}(h:Enumerated list start value not ordinal-1: "C" (ordinal 3)h]h>Enumerated list start value not ordinal-1: “C” (ordinal 3)}(hjm hhhNhNubah}(h]h ]h"]h$]h&]uh1hhjj ubah}(h]h ]h"]h$]h&]levelKtypejg sourcehlineKuh1jL hjBhhhhhKubjM )}(hhh]h)}(h:Enumerated list start value not ordinal-1: "b" (ordinal 2)h]h>Enumerated list start value not ordinal-1: “b” (ordinal 2)}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj ubah}(h]h ]h"]h$]h&]levelKtypejg sourcehlineKuh1jL hjubetransform_messages] transformerN include_log] decorationNhhub.