I know that you Linux gurus out there are going to think me a total nube, but I just can't figure this out...
Background: I built an expansion board for the NGW100 that plugs onto J5 J6. It has an RS232 driver on USART2 and an RS485 driver on USART3. I have a complete development environment with Fedora on a VM. I have successfully used buildroot to create an image to load on the target. I am booting off a 256M SD card and have a few different versions of the Linux uImage in the /boot directory. I can use u-boot to manually load and execute any one I choose.
Now my problem: I read here in another thread that to activate the additional USARTs that I had to modify the 'setup.c' file. Unfortunately there are zillions of setup.c files in the buildroot tree. I grep'ed for the one that contained 'at32_map_usart'. I found two. one was in...
the other was in..
I edited both files to add the additional lines for just USART2 for now. I did a...
It created a new uImage that was the identical size of the previous build that I did. I booted it anyway... no USART2.
So, within buildroot, when I want to edit a kernel C source file and then re-build a new kernel including my changes, where are the files that I should be editing?