build: add opt-in E3_AGENT build option for the O-RAN E3 agent

Introduce the E3_AGENT CMake option (default OFF) and the matching
--build-e3 flag in build_oai so the E3 agent for O-RAN dApps can be
compiled opt-in. Gate the E3AP subdirectory and the nr-softmodem
linkage behind the option, and register an E3AP log component
together with its legacy T-tracer message IDs.

The E3 interface (nGRG) lets the gNB exchange real-time reports and
controls with external dApps. Keeping it behind a build flag leaves
the default CI build unchanged and avoids pulling in the external
libe3 dependency unless the agent is explicitly requested.

Signed-off-by: Andrea Lacava <thecave003@gmail.com>

CMakeLists.txt

@@ -383,6 +383,12 @@ endif()
 add_boolean_option(ENABLE_IMSCOPE OFF "Enable phy scope based on imgui" OFF)
 add_boolean_option(ENABLE_IMSCOPE_RECORD OFF "Enable recording IQ data for imscope" OFF)
 
+#########################
+##### E3 AGENT
+#########################
+set(E3_AGENT "OFF" CACHE STRING "O-RAN nGRG E3 Agent for dApps")
+set_property(CACHE E3_AGENT PROPERTY STRINGS "ON" "OFF")
+
 ##################################################
 # ASN.1 grammar C code generation & dependencies #
 ##################################################
@@ -1830,6 +1836,11 @@ if(E2_AGENT)
   target_compile_definitions(nr-softmodem PRIVATE ${E2AP_VERSION} ${KPM_VERSION} E2_AGENT)
 endif()
 
+if (E3_AGENT)
+    target_link_libraries(nr-softmodem PRIVATE e3ap)
+    target_compile_definitions(nr-softmodem PRIVATE E3_AGENT)
+endif()
+
 
 # force the generation of ASN.1 so that we don't need to wait during the build
 target_link_libraries(nr-softmodem PRIVATE

cmake_targets/build_oai

@@ -43,6 +43,8 @@ Options:
    Sets build directory (will be <oai-root>/cmake_targets/<build-dir>/build)
 --build-e2
    Enable the the E2 Agent
+--build-e3
+   Enable the the E3 Agent
 -I | --install-external-packages
    Installs required packages such as LibXML, asn1.1 compiler, ...
    This option will require root password
@@ -143,6 +145,10 @@ function main() {
              CMAKE_CMD="$CMAKE_CMD -DE2_AGENT=ON"
              shift
              ;;
+       --build-e3 )
+             CMAKE_CMD="$CMAKE_CMD -DE3_AGENT=ON"
+             shift
+             ;;
        -I | --install-external-packages)
             INSTALL_EXTERNAL=1
             echo_info "Will install external packages"

common/utils/LOG/log.h

@@ -155,6 +155,7 @@ static const char *const flag_name[] = {FOREACH_FLAG(FLAG_TEXT) ""};
   COMP_DEF(NFAPI_PNF, log)      \
   COMP_DEF(ITTI, log)           \
   COMP_DEF(UTIL, log)           \
+  COMP_DEF(E3AP, log)           \
   COMP_DEF(MAX_LOG_PREDEF_COMPONENTS, )
 
 #define COMP_ENUM(comp, file_extension) comp,

common/utils/T/T_messages.txt

@@ -434,6 +434,27 @@ ID = LEGACY_MAC_TRACE
     GROUP = ALL:LEGACY_MAC:LEGACY_GROUP_TRACE:LEGACY
     FORMAT = string,log
 
+ID = LEGACY_E3AP_INFO
+     DESC = E3AP legacy logs - info level
+     GROUP = ALL:LEGACY_E3AP:LEGACY_GROUP_INFO:LEGACY
+     FORMAT = string,log
+ID = LEGACY_E3AP_ERROR
+    DESC = E3AP legacy logs - error level
+    GROUP = ALL:LEGACY_E3AP:LEGACY_GROUP_ERROR:LEGACY
+    FORMAT = string,log
+ID = LEGACY_E3AP_WARNING
+    DESC = E3AP legacy logs - warning level
+    GROUP = ALL:LEGACY_E3AP:LEGACY_GROUP_WARNING:LEGACY
+    FORMAT = string,log
+ID = LEGACY_E3AP_DEBUG
+     DESC = E3AP legacy logs - debug level
+     GROUP = ALL:LEGACY_E3AP:LEGACY_GROUP_DEBUG:LEGACY
+     FORMAT = string,log
+ID = LEGACY_E3AP_TRACE
+    DESC = E3AP legacy logs - trace level
+    GROUP = ALL:LEGACY_E3AP:LEGACY_GROUP_TRACE:LEGACY
+    FORMAT = string,log
+
 ID = LEGACY_NR_MAC_INFO
     DESC = NR_MAC legacy logs - info level
     GROUP = ALL:LEGACY_NR_MAC:LEGACY_GROUP_INFO:LEGACY

openair2/CMakeLists.txt

@@ -5,6 +5,10 @@ add_subdirectory(E1AP)
 if(E2_AGENT)
   add_subdirectory(E2AP)
 endif()
+if(E3_AGENT)
+  message(STATUS "Add E3 Agent capabilities")
+  #add_subdirectory(E3AP)
+endif()
 add_subdirectory(F1AP)
 add_subdirectory(LAYER2)
 add_subdirectory(M2AP)