[posix] add RT_USING_POSIX_SOCKET (#5731)

bsp/qemu-vexpress-a9/drivers/Kconfig

@@ -46,8 +46,8 @@ endif
 config BSP_DRV_EMAC
     bool "Enable EMAC driver"
     select RT_USING_LWIP
-    select RT_USING_SAL
-    select SAL_USING_POSIX
+    select RT_USING_POSIX_FS
+    select RT_USING_POSIX_SOCKET
     default n
 
 config BSP_DRV_AUDIO

bsp/stm32/stm32f407-atk-explorer/board/Kconfig

@@ -83,13 +83,8 @@ menu "Onboard Peripheral Drivers"
         default n
         select RT_USING_LWIP
         select RT_LWIP_USING_HW_CHECKSUM
-
-    config BSP_USING_ETH_SAL
-        bool "Enable Ethernet with SAL"
-        depends on BSP_USING_ETH
-        default y
-        select RT_USING_SAL
-        select SAL_USING_POSIX
+        select RT_USING_POSIX_FS
+        select RT_USING_POSIX_SOCKET
 
     config PHY_USING_LAN8720A
         bool

components/libc/posix/Kconfig

@@ -26,6 +26,12 @@ if RT_USING_POSIX_FS
         select RT_USING_POSIX_POLL
         default n
 
+    config RT_USING_POSIX_SOCKET
+        bool "Enable BSD Socket I/O <sys/socket.h> <netdb.h>"
+        select RT_USING_POSIX_SELECT
+        select RT_USING_SAL
+        default n
+
     config RT_USING_POSIX_TERMIOS
         bool "Enable Terminal I/O <termios.h>"
         select RT_USING_POSIX_STDIO

components/net/sal/Kconfig

@@ -35,19 +35,16 @@ if RT_USING_SAL
     endif
 
     config SAL_USING_POSIX
-        bool "Enable BSD socket operated by file system API"
-        default n
-        select RT_USING_POSIX_FS
-        select RT_USING_POSIX_SELECT
+        bool
+        depends on DFS_USING_POSIX
+        default y
         help
+            Enable BSD socket operated by file system API
             Let BSD socket operated by file system API, such as read/write and involveed in select/poll POSIX APIs.
 
-    if !SAL_USING_POSIX
-
-        config SAL_SOCKETS_NUM
-            int "the maximum number of sockets"
-            default 16
-
-    endif
+    config SAL_SOCKETS_NUM
+        int "the maximum number of sockets"
+        depends on !SAL_USING_POSIX
+        default 16
 
 endif