Wi-Fi DFS PRF/PPS to PRi

how to find the location of installed packages (or libraries)

sudo dpkg -L packagename

sudo dpkg -L libnl-3-dev

sudo apt install libnl-genl-3-dev

sudo dpkg -L libnl-genl-3-dev

finding missing header files in ubuntu

sudo apt install apt-file

apt-file update

apt-file search netlink/genl/genl.h

libnl-3-dev: /usr/include/libnl3/netlink/genl/genl.h

sudo apt-get install libnl-3-dev

batch renaming files in linux

sudo apt install mmv

mmv "*.patch" "c00-#1.patch"

c programming variables' memory location check

gcc -O0 memory.c -Wl,-Map=output.map

memory map of memory sections

https://www.ele.uva.es/~jesus/hardware_empotrado/Compiler.pdf

sparse build check

https://kernelnewbies.org/Sparse

sudo apt-get install sparse

How to use sparse

Choose a subdirectory in the kernel tree that you want to check for sparse warnings and errors, for instance that could be drivers/staging/wlan-ng, and do:

$ make C=2 drivers/staging/wlan-ng/

You can use the variable CF to pass more checkflags to sparse. For example, you can enable endian checks doing:

$ make C=2 CF="-D__CHECK_ENDIAN__" drivers/staging/wlan-ng/

The warnings produced indicate sites in code where types relevant to byteorder are mixed, possibly leading to buggy behavior.

You can observe what are the default checkflags set in the Makefile. You will see something close to the following:

CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
                  -Wbitwise -Wno-return-void $(CF)

http://jake.dothome.co.kr/sparse/


* smatch ??
http://smatch.sourceforge.net/
http://events.linuxfoundation.org/sites/events/files/slides/Static%20code%20checking.pdf

802.11ac Max. length of A-MPDU

Maximum A-MPDU Length Exponent

Indicates the maximum length of A-MPDU that the STA can receive.
EOF padding is not included in this limit.

This field is an integer in the range of 0 to 7.
The length defined by this field is equal to
2 ^(13 + Maximum A-MPDU Length Exponent) – 1 octets.


Following are some of the useful attributes of 11ac MAC layer.
•  MSDU size for MAC payload - 2304
•  MPDU size for MAC frame - 11,454
•  PSDU size(PLCP payload) - About 4MB
•  PPDU size(PLCP frame) - 5.484 ms

hostapd.conf

MAX-A-MPDU-LEN-EXP1 ~ MAX-A-MPDU-LEN-EXP7
MAX-MPDU-7991 or MAX-MPDU-11454