How I started:
I have a defective Acer Laptop with a working 15.4" Normally Landscape Display. The LCD panel is suitable to salvage for now.
Then I have a Chinese made tablet, FnF i5 mini 2, it has a damaged Digitizer and LCD 7" display, yet its MOBO still lives!
I am able to setup the Tablet to connect on to my TV thru its HDMI, a large TV that consumes more power in order to watch movies and the rest thru the Android (HDMI).
So I figured, surely I can re-route the LVDS cable from the 15" in replacement to the broken 7" tablet, then yields to a better less consuming Multi-media device. A way that I will control the Tablet would be thru a DIY powered USB hub via the OTG (mouse and Keyboard). For now, I am controlling the broken tablet via VNC without a physical display.
So here is what I got:
It turns out that the 7" LCD panel for the tablet is set to be NORMALLY PORTRAIT, yet the 15" LCD from the laptop was Landscape.
with further research, a Replacement LCD Manufacturer indicated that;
Linux kernel allows to assign manual LCD resolution in bootargs supplied by u-boot. This is usually done by script called “boot.scr” in “boot” partition that is loaded and executed by u-boot. “boot.scr” has special format and usually is created with the help of “mkimage” util from source file called “boot.txt”. Below is example of my “boot.txt” that I use for Android (Linaro build 12.01):
The most important bootarg here is “omapfb.video_mode=1024x600MR-16@60” – that’s exactly where we setup LCD resolution. 1024×600 sets resolution, “M” indicates the kernel will calculate a VESA mode on-the-fly instead of using modedb look-up, the “R” indicates reduced blanking which is for LCD panels, “16” is the color depth, “@60” is the # of frames per second.
Lets generate “boot.scr” file with the following commands:
mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n "Run uImage" -d boot.txt boot.scr
chmod a+x boot.scr
“mkimage” is available in package “uboot-mkimage”.
The FnF Ifive Mini 2 has 800x1280 according the the datasheet, morelikely is also indicated on the BOOT.SCR (if there is Boot.scr) for the JB 4.1.1
Current Challenge. I have scanned and search for a file named "BOOT.SCR" using ES-FIlemngr thru search, no relative file found. I might be looking for a different file...
I call upon all the android experts, the chef!