/dev/fb0 is the framebuffer. So yes, you can feed data into the filesystem and you’ll see it on your display.
For Unixoids, being a file does not mean that this data is stored on a hard disk, but that all data, processes and hardware are accessible with the same toolkit. /dev/fb0, for instance, is part of the file-like interface of your graphics card.
/dev/fb is mostly one thing: deprecated. Also it is not really a interface of your graphics card, it is a legacy way kindly still provided for pushing fullscreen pixels to your monitor in an unaccelerated fashion for things that have not made it to kms drm (which at this point is pretty much merely the console emulation on the TTYs). It is not an interface to the graphics card, because it doesn’t provide any capabilities a graphics card has (like shaders etc). In fact for just pushing pixels you can leave any graphics card completely out of your computer if you connect your screen by other means (think stuff like SPI which is common in embedded devices; you can find many examples of such drivers in the kernel source at drivers/gpu/drm/tiny ).
/dev/fb0 is the framebuffer. So yes, you can feed data into the filesystem and you’ll see it on your display.
For Unixoids, being a file does not mean that this data is stored on a hard disk, but that all data, processes and hardware are accessible with the same toolkit. /dev/fb0, for instance, is part of the file-like interface of your graphics card.
/dev/fb is mostly one thing: deprecated. Also it is not really a interface of your graphics card, it is a legacy way kindly still provided for pushing fullscreen pixels to your monitor in an unaccelerated fashion for things that have not made it to kms drm (which at this point is pretty much merely the console emulation on the TTYs). It is not an interface to the graphics card, because it doesn’t provide any capabilities a graphics card has (like shaders etc). In fact for just pushing pixels you can leave any graphics card completely out of your computer if you connect your screen by other means (think stuff like SPI which is common in embedded devices; you can find many examples of such drivers in the kernel source at drivers/gpu/drm/tiny ).