Changing the frame buffer settings

Q. How do i change the frame buffer settings to select the correct BGR setting.

I believe i have found where the struct is defined which is in drivers/video/fbdev/imxfb.c

/* Actually this really is 18bit support, the lowest 2 bits of each colour
 * are unused in hardware. We claim to have 24bit support to make software
 * like X work, which does not support 18bit.
static struct imxfb_rgb def_rgb_18 = {
	.red	= {.offset = 16, .length = 8,},
	.green	= {.offset = 8, .length = 8,},
	.blue	= {.offset = 0, .length = 8,},
	.transp = {.offset = 0, .length = 0,},

I am not sure what files actually use the ‘imxfb_rgb def_rgb_18’ so i can change it to a new one

HI @adrian

Thanks for writing to the Toradex Support!
Could you provide the version of the Hardware (including carrier board) and Software of your module?

What are you trying to do? what is your application?

Best regards,


I am using the IMX6ULL board.

Previously i have used a module from DIGI and i had to change the frame buffer settings so that it has the correct bit length and offset for red, blue & green settings

But what exact hardware (module and carrier board) and software versions of things are you talking about? And what exact display are you targetting?

The following article may be useful as well: