Generalizing config.bcm support for BRCM silicons (sonic-net#693)

* Per-switching silicon Common config for Broadcom Supported Platforms.

syncd/scripts/syncd_init_common.sh

@@ -89,15 +89,78 @@ function set_start_type()
 
 config_syncd_bcm()
 {
-    if [ -f "/etc/sai.d/sai.profile" ]; then
-        CMD_ARGS+=" -p /etc/sai.d/sai.profile"
+
+    if [ -f $PLATFORM_DIR/common_config_support ];then
+
+      PLATFORM_COMMON_DIR=/usr/share/sonic/device/x86_64-broadcom_common
+
+      cp -f $HWSKU_DIR/*.config.bcm /tmp
+      cp -f /etc/sai.d/sai.profile /tmp
+      CONFIG_BCM=$(find /tmp -name '*.bcm')
+      PLT_CONFIG_BCM=$(find $HWSKU_DIR -name '*.bcm')
+      SAI_PROFILE=$(find /tmp -name 'sai.profile')
+      sed -i 's+/usr/share/sonic/hwsku+/tmp+g' $SAI_PROFILE
+
+      #Get first three characters of chip id
+      readline=$(grep '0x14e4' /proc/linux-kernel-bde)
+      chip_id=${readline#*0x14e4:0x}
+      chip_id=${chip_id::3}
+      COMMON_CONFIG_BCM=$(find $PLATFORM_COMMON_DIR/x86_64-broadcom_${chip_id} -name '*.bcm')
+
+      if [ -f $PLATFORM_COMMON_DIR/x86_64-broadcom_${chip_id}/*.bcm ]; then
+         for file in $CONFIG_BCM; do
+             echo "" >> $file
+             echo "# Start of chip common properties" >> $file
+             while read line
+             do
+               line=$( echo $line | xargs )
+               if [ ! -z "$line" ];then
+                   if [ "${line::1}" == '#' ];then
+                       echo $line >> $file
+                   else
+                       sedline=${line%=*}
+                       if grep -q $sedline $file ;then
+                          echo "Keep the config $(grep $sedline $file) in $file"
+                       else
+                          echo $line >> $file
+                       fi
+                   fi
+               fi
+             done < $COMMON_CONFIG_BCM
+             echo "# End of chip common properties" >> $file
+         done
+         echo "Merging $PLT_CONFIG_BCM with $COMMON_CONFIG_BCM, merge files stored in $CONFIG_BCM"
+      fi
+
+      #sync the file system
+      sync
+
+      # copy the final config.bcm and sai.profile to the shared folder for 'show tech'
+      cp -f /tmp/sai.profile /var/run/sswsyncd/
+      cp -f /tmp/*.bcm /var/run/sswsyncd/
+
+      if [ -f "/tmp/sai.profile" ]; then
+          CMD_ARGS+=" -p /tmp/sai.profile"
+      elif [ -f "/etc/sai.d/sai.profile" ]; then
+          CMD_ARGS+=" -p /etc/sai.d/sai.profile"
+      else
+          CMD_ARGS+=" -p $HWSKU_DIR/sai.profile"
+      fi
+
     else
-        CMD_ARGS+=" -p $HWSKU_DIR/sai.profile"
+
+      if [ -f "/etc/sai.d/sai.profile" ]; then
+          CMD_ARGS+=" -p /etc/sai.d/sai.profile"
+      else
+          CMD_ARGS+=" -p $HWSKU_DIR/sai.profile"
+      fi
+
     fi
 
     [ -e /dev/linux-bcm-knet ] || mknod /dev/linux-bcm-knet c 122 0
     [ -e /dev/linux-user-bde ] || mknod /dev/linux-user-bde c 126 0
     [ -e /dev/linux-kernel-bde ] || mknod /dev/linux-kernel-bde c 127 0
+
 }
 
 config_syncd_mlnx()