Hi Jeff,
I am stil trying to have acces to channel 13 of my router radio when I connect the second radio usb wifi dongle to it.
I was thinking at modifing the db.txt file of the openwrt/pakage/firmware/wireless-regdb package.
Problem is that the makefile points to a git repo, so I was wondering If I could download the repo locally, modify the db.txt and then having makefile to point to the offline copy of the repo.
I read about the buildroot override-srcdir mechanism, but I am not sure it would be feasible with openwrt buildroot, I cannot find the the 'Build options' sub-menu:
($(CONFIG_DIR)/local.mk) location of a package override file as per:
http://lists.busybox.net/pipermail/buildroot/2016-June/165282.html
where:
So, by default, Buildroot will look for a file named "local.mk" in the
same directory with the .config file. You can change the location where
to find that file. If it does not exist, that's not an error. If it
exists, Buildroot will parse it.
The local.mk file is suposed to include override-srcdir directives, like
so:
MY_PACKAGE_OVERRIDE_SRCDIR = /path/to/my/local/source/for/my/package
For example:
LINUX_OVERRIDE_SRCDIR = /path/to/my/linux
UBOOT_OVERRIDE_SRCDIR = /path/to/my/uboot
With those, Buildroot will conclude that it should download the affected
package, and just use the sources it finds in the specified directory.
Note that Buildroot will not apply any patches in this case; you are
responsbile for propagating whatever patch you need. Buildroot jsut use
the sources as-is.
moreover I'll have to figure out what about the patches inside openwrt/package/firmware/wireless-regdb/patches.
Just speculating
This channel 13 problem is bugging me a lot 
I havent read anything at all about patches, so far. Please point me towards and easy explanation web available, of them, will you ?. I red about the build and compiling but everything is still confusing to me.
If the patches files describe the difference between the sources invoked by makefile and the one modified by myself ...... but still dont understand how they are managed by buildroot.
Thanks again
Best
P.
got the hyperlink about patches I am on them