I have a device (i.MX6DL based) that needs to present to the user a configurable (based on GPIO input) boot screen and I have chosen to do this through U-Boot due to the boot time of Linux and Application code.
My problem is that when Linux starts booting, the screen is blanked and it is some seconds before application code is drawing to the screen.
I have done some research into the Device Tree Settings for IPU (BYPASS_RESET) and FB (LATE_INIT), but am finding no matter the setting, in the file (mxc_ipuv3_fb.c) if the FB Start & Len (smem_start & smem_len) are not defined, a routine (mxcfb_map_video_memory) is called where at the end, the screen is cleared.
I see in mxcfb_probe where the LATE_INIT device tree setting is read, but I also see following a platform_get_resource which looks to be trying to see if start & end are defined.
Where I am stumped is how to define this Start & End: Both in the FB section and in the Memory section. I believe these need to either be passed from U-Boot or predefined in U-Boot & Linux Device Tree. I did not see in any of the device tree Documentation anything suggesting how this should be done...
Does anyone have any example or documentation of how this should be done??
Thanks in advance for your advice....