diff --git a/doc/BUILD.md b/doc/BUILD.md
index a52ce98cb53f7df132d6b55d64902b32fb7c1036..70d69f5afde23705a7f055e636ef9d61f467d7ba 100644
--- a/doc/BUILD.md
+++ b/doc/BUILD.md
@@ -193,6 +193,7 @@ Using the help option of the build script you can get the list of available opti
 | --UE                                                        | maintained and tested in CI                 | build `lte-uesoftmodem` the LTE UE                           |
 | --gNB                                                       | maintained and tested in CI                 | build `nr-softmodem` the 5G gNodeB                           |
 | --nrUE                                                      | maintained and tested in CI                 | build `nr-uesoftmodem` the 5G UE                             |
+| --arch-native                                               | maintained                                  | build with native architecture optimization                  |
 | --usrp-recplay                                              | deprecated                                  | use the USRP configuration parameters to use the record player. |
 | --build-lib                                                 | maintained                                  | build  optional shared library(ies), which can then be loaded at run time via command line option. Use the --help option to get the list of supported optional libraries. `all` can be used to build all available optional libraries. |
 | --UE-conf-nvram                                             | maintained                                  | Specifies the path to the input file used by the conf2uedata utility. defaults to [openair3/NAS/TOOLS/ue_eurecom_test_sfr.conf](../openair3/NAS/TOOLS/ue_eurecom_test_sfr.conf) |
diff --git a/doc/TESTING_5GSA_setup.md b/doc/TESTING_5GSA_setup.md
index 9b27549df438ffda963222e04c23435aecbba53c..357c62c813993ab5adedaf3afb3685687ef45729 100644
--- a/doc/TESTING_5GSA_setup.md
+++ b/doc/TESTING_5GSA_setup.md
@@ -50,7 +50,7 @@ At the moment of writing this document interoperability with the following COTS
 ## 1.1  gNB build and configuration
 To get the code and build the gNB executable:
 
-### Ubuntu 18.04
+### Build gNB
 ```bash
     git clone https://gitlab.eurecom.fr/oai/openairinterface5g.git
     git checkout develop
@@ -61,42 +61,6 @@ To get the code and build the gNB executable:
     ./build_oai --gNB -w USRP
 ```
 
-### Ubuntu 20.04
-```bash
-    # Build UHD from source
-    # https://files.ettus.com/manual/page_build_guide.html
-    sudo apt-get install libboost-all-dev libusb-1.0-0-dev doxygen python3-docutils python3-mako python3-numpy python3-requests python3-ruamel.yaml python3-setuptools cmake build-essential
-    
-    git clone https://github.com/EttusResearch/uhd.git
-    cd uhd/host
-    mkdir build
-    cd build
-    cmake ../
-    make -j 4
-    make test # This step is optional
-    sudo make install
-    sudo ldconfig
-    sudo uhd_images_downloader
-
-
-    git clone https://gitlab.eurecom.fr/oai/openairinterface5g.git
-    git checkout develop
-    
-    # Install dependencies in Ubuntu 20.04
-    cd
-    cd openairinterface5g/
-    source oaienv
-    cd cmake_targets/
-    ./install_external_packages.ubuntu20
-    
-    # Build OAI gNB
-    cd
-    cd openairinterface5g/
-    source oaienv
-    cd cmake_targets/
-    ./build_oai --gNB -w USRP
-```
-
 A reference configuration file for the **monolithic** gNB is provided  [here](https://gitlab.eurecom.fr/oai/openairinterface5g/-/blob/develop/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.fr1.106PRB.usrpb210.conf).