Missing kconfig in linux-headers when compiling kernel module (after 5.x)

[ecrin4102]

Since the kernel version 5.x, linux headers seems to not have all of files needed to build a kernel module. I have tried 3 versions 5.10.168-ti-rt-r79, 6.1.80-ti-rt-r34, 6.1.83-ti-rt-r35 with different way to install headers:

• With "sudo apt install linux-headers-x.x.xx-ti-rt-rxx"
• With build_deb.sh
• With insmod kheader

After that, if I compile my kernel module with:
sudo make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

I get this error:

make -C /lib/modules/6.1.83-ti-rt-r35/build M= modules
make[1]: Entering directory '/usr/src/linux-headers-6.1.83-ti-rt-r35'
  SYNC    include/config/auto.conf.cmd
can't find file Kconfig
make[3]: *** [scripts/kconfig/Makefile:77: syncconfig] Error 1
make[2]: *** [Makefile:703: syncconfig] Error 2
make[1]: *** [Makefile:804: include/config/auto.conf.cmd] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-6.1.83-ti-rt-r35'
make: *** [Makefile:7: module] Error 2

The content of /usr/src/linux-headers-xxxxx is indeed almost empty:

ls /usr/src/linux-headers-6.1.83-ti-rt-r35/
arch  include  Makefile  Module.symvers  scripts

Compare to a kernel which works:

ls /usr/src/linux-headers-4.19.94-ti-rt-r74/
arch   crypto         firmware  init     kernel    mm              samples   sound  virt
block  Documentation  fs        ipc      lib       Module.symvers  scripts   tools
certs  drivers        include   Kconfig  Makefile  net             security  usr