Documentation Question

I am working on a configuration with a Orin NX and our own carrier board. While doing the configuraton I am walking thru the documentation in Pinmux and GPIO Configuration — Jetson Linux Developer Guide documentation it references files in hardware/nvidia/platform/t23x//bct/ in my configuration under the Linux_for_Tegra/source/public/hardware/nvidia/platform/t23x/ I do not see a bct directory. Am I looking at the wrong location where I want to place my pinmux, gpio, and pad configuration files? I put them under bootloader/t186ref/BCT but I suspect that is just for the bootloader and not the linux boot.