TS-4900 Device Tree
On startup U-boot can load several device trees to attempt to find the right matching device tree. By default, it will load in this order:
If the board is a REV E or later:
imx6<cpu>-ts4900-reve-<baseboard id>.dtb imx6<cpu>-ts4900-reve.dtb imx6<cpu>-ts4900-<baseboard id>.dtb imx6<cpu>-ts4900.dtb
If the board is REV D or earlier:
imx6<cpu>-ts4900-<baseboard id>.dtb imx6<cpu>-ts4900.dtb
For example, on a Quad core i.MX6 REV E TS-4900 on a TS-TPC-8390, this will attempt to load these files:
imx6q-ts4900-reve-2.dtb imx6q-ts4900-reve.dtb imx6q-ts4900-2.dtb imx6q-ts4900.dtb
The last device tree in the list is a "fallback" device tree that exposes most basic functionality. On the development TS-8550 board, this will intentionally fall back to this device tree.
In the kernel sources, the device tree source files are found in arch/arm/boot/dts/. The majority of the devices are found in: imx6qdl-ts4900.dtsi and imx6qdl-ts4900-reve.dtsi. For custom baseboards it will be simplest to modify these dtsi files directly.