hey guys
I am beginner in embedded linux. I want to send some data to a FPGA with GPMC port of a beaglebone black board. I'm using kernel version "Linux beaglebone 4.14.79-ti-r84 #1 SMP PREEMPT Tue Nov 13 20:11:18 UTC 2018 armv7lGNU/Linux". I wrote a simple dts and then complied it and finally added this file "uboot_overlay_addr4=/lib/firmware/CUSTOM-GPMC-00A0.dtbo" to/boot/uEnv.txt file. after reboot I checked the /sys/kernel/debug/pincntrl/44e.../pingroups file. I can see that gmpc is added to this file. but when I check the /sys/kernel/debug/pincntrl/44e.../pins file, the their values do not match with values I have set in dts file. when I want to write to gmpc address with mmap function I receive bus error. could you please tell me what I should do?
thanks in advance.