imfs: Replace devfs with an IMFS specialization

Add a simplified path evaluation function IMFS_eval_path_devfs() for a
device only IMFS configuration.

The code size can be further reduced by the application if it disables
the support for legacy IO drivers via:

  #define CONFIGURE_IMFS_DISABLE_MKNOD
  #define CONFIGURE_IMFS_DISABLE_MKNOD_DEVICE

Obsolete CONFIGURE_MAXIMUM_DEVICES.  Remove BSP_MAXIMUM_DEVICES.

Update #3894.
Update #3898.

3 files changed, 42 insertions, 65 deletions

diff --git a/cpukit/include/rtems/confdefs/bsp.h b/cpukit/include/rtems/confdefs/bsp.h
index 9af46a8d29..7237c03522 100644
--- a/cpukit/include/rtems/confdefs/bsp.h
+++ b/cpukit/include/rtems/confdefs/bsp.h
@@ -48,7 +48,6 @@
   #undef BSP_IDLE_TASK_STACK_SIZE
   #undef BSP_INITIAL_EXTENSION
   #undef BSP_INTERRUPT_STACK_SIZE
-  #undef BSP_MAXIMUM_DEVICES
   #undef CONFIGURE_BSP_PREREQUISITE_DRIVERS
   #undef CONFIGURE_MALLOC_BSP_SUPPORTS_SBRK
 #else
diff --git a/cpukit/include/rtems/confdefs/libio.h b/cpukit/include/rtems/confdefs/libio.h
index 3c45771952..603b2882c1 100644
--- a/cpukit/include/rtems/confdefs/libio.h
+++ b/cpukit/include/rtems/confdefs/libio.h
@@ -47,7 +47,6 @@
 #include <rtems/sysinit.h>
 
 #ifdef CONFIGURE_FILESYSTEM_ALL
-  #define CONFIGURE_FILESYSTEM_DEVFS
   #define CONFIGURE_FILESYSTEM_DOSFS
   #define CONFIGURE_FILESYSTEM_FTPFS
   #define CONFIGURE_FILESYSTEM_IMFS
@@ -57,12 +56,6 @@
   #define CONFIGURE_FILESYSTEM_TFTPFS
 #endif
 
-#ifdef CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM
-  #define CONFIGURE_FILESYSTEM_DEVFS
-#elif !defined(CONFIGURE_APPLICATION_DISABLE_FILESYSTEM)
-  #define _CONFIGURE_USE_IMFS_AS_BASE_FILESYSTEM
-#endif
-
 #ifdef CONFIGURE_USE_MINIIMFS_AS_BASE_FILESYSTEM
   #ifdef CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM
     #error "CONFIGURE_USE_MINIIMFS_AS_BASE_FILESYSTEM cannot be used together with CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM"
@@ -78,6 +71,21 @@
   #define CONFIGURE_IMFS_DISABLE_UTIME
 #endif
 
+#ifdef CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM
+  #define CONFIGURE_IMFS_DISABLE_CHMOD
+  #define CONFIGURE_IMFS_DISABLE_CHOWN
+  #define CONFIGURE_IMFS_DISABLE_LINK
+  #define CONFIGURE_IMFS_DISABLE_MKNOD_FILE
+  #define CONFIGURE_IMFS_DISABLE_MOUNT
+  #define CONFIGURE_IMFS_DISABLE_READDIR
+  #define CONFIGURE_IMFS_DISABLE_READLINK
+  #define CONFIGURE_IMFS_DISABLE_RENAME
+  #define CONFIGURE_IMFS_DISABLE_RMNOD
+  #define CONFIGURE_IMFS_DISABLE_SYMLINK
+  #define CONFIGURE_IMFS_DISABLE_UNMOUNT
+  #define CONFIGURE_IMFS_DISABLE_UTIME
+#endif
+
 #ifdef CONFIGURE_APPLICATION_DISABLE_FILESYSTEM
   #ifdef CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM
     #error "CONFIGURE_APPLICATION_DISABLE_FILESYSTEM cannot be used together with CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM"
@@ -87,10 +95,6 @@
     #error "CONFIGURE_APPLICATION_DISABLE_FILESYSTEM cannot be used together with CONFIGURE_USE_MINIIMFS_AS_BASE_FILESYSTEM"
   #endif
 
-  #ifdef CONFIGURE_FILESYSTEM_DEVFS
-    #error "CONFIGURE_APPLICATION_DISABLE_FILESYSTEM cannot be used together with CONFIGURE_FILESYSTEM_DEVFS"
-  #endif
-
   #ifdef CONFIGURE_FILESYSTEM_DOSFS
     #error "CONFIGURE_APPLICATION_DISABLE_FILESYSTEM cannot be used together with CONFIGURE_FILESYSTEM_DOSFS"
   #endif
@@ -118,13 +122,9 @@
   #ifdef CONFIGURE_FILESYSTEM_TFTPFS
     #error "CONFIGURE_APPLICATION_DISABLE_FILESYSTEM cannot be used together with CONFIGURE_FILESYSTEM_TFTPFS"
   #endif
-#else
-  #define _CONFIGURE_FILESYSTEM_INITIALIZE
 #endif
 
-#ifdef CONFIGURE_FILESYSTEM_DEVFS
-#include <rtems/devfs.h>
-#endif
+#include <rtems/imfs.h>
 
 #ifdef CONFIGURE_FILESYSTEM_DOSFS
 #include <rtems/dosfs.h>
@@ -134,11 +134,6 @@
 #include <rtems/ftpfs.h>
 #endif
 
-#if defined(CONFIGURE_FILESYSTEM_IMFS) \
-  || defined(_CONFIGURE_USE_IMFS_AS_BASE_FILESYSTEM)
-#include <rtems/imfs.h>
-#endif
-
 #ifdef CONFIGURE_FILESYSTEM_JFFS2
 #include <rtems/jffs2.h>
 #endif
@@ -159,28 +154,7 @@
 extern "C" {
 #endif
 
-#ifdef CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM
-
-#ifndef CONFIGURE_MAXIMUM_DEVICES
-  #ifdef BSP_MAXIMUM_DEVICES
-    #define CONFIGURE_MAXIMUM_DEVICES BSP_MAXIMUM_DEVICES
-  #else
-    #define CONFIGURE_MAXIMUM_DEVICES 4
-  #endif
-#endif
-
-static devFS_node devFS_root_filesystem_nodes[ CONFIGURE_MAXIMUM_DEVICES ];
-
-static const devFS_data _Filesystem_Root_data = {
-  devFS_root_filesystem_nodes,
-  CONFIGURE_MAXIMUM_DEVICES
-};
-
-#define _CONFIGURE_FILESYSTEM_ROOT_TYPE RTEMS_FILESYSTEM_TYPE_DEVFS
-
-#endif /* CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM */
-
-#ifdef _CONFIGURE_USE_IMFS_AS_BASE_FILESYSTEM
+#ifndef CONFIGURE_APPLICATION_DISABLE_FILESYSTEM
 
 #ifndef CONFIGURE_IMFS_MEMFILE_BYTES_PER_BLOCK
   #define CONFIGURE_IMFS_MEMFILE_BYTES_PER_BLOCK \
@@ -198,12 +172,16 @@ static const devFS_data _Filesystem_Root_data = {
 
 const int imfs_memfile_bytes_per_block = CONFIGURE_IMFS_MEMFILE_BYTES_PER_BLOCK;
 
-static IMFS_fs_info_t _IMFS_fs_info;
+static IMFS_fs_info_t IMFS_root_fs_info;
 
-static const rtems_filesystem_operations_table _IMFS_ops = {
+static const rtems_filesystem_operations_table IMFS_root_ops = {
   rtems_filesystem_default_lock,
   rtems_filesystem_default_unlock,
-  IMFS_eval_path,
+  #ifdef CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM
+    IMFS_eval_path_devfs,
+  #else
+    IMFS_eval_path,
+  #endif
   #ifdef CONFIGURE_IMFS_DISABLE_LINK
     rtems_filesystem_default_link,
   #else
@@ -266,13 +244,17 @@ static const rtems_filesystem_operations_table _IMFS_ops = {
   rtems_filesystem_default_statvfs
 };
 
-static const IMFS_mknod_controls _IMFS_mknod_controls = {
+static const IMFS_mknod_controls IMFS_root_mknod_controls = {
   #ifdef CONFIGURE_IMFS_DISABLE_READDIR
     &IMFS_mknod_control_dir_minimal,
   #else
     &IMFS_mknod_control_dir_default,
   #endif
-  &IMFS_mknod_control_device,
+  #ifdef CONFIGURE_IMFS_DISABLE_MKNOD_DEVICE
+    &IMFS_mknod_control_enosys,
+  #else
+    &IMFS_mknod_control_device,
+  #endif
   #ifdef CONFIGURE_IMFS_DISABLE_MKNOD_FILE
     &IMFS_mknod_control_enosys,
   #else
@@ -285,18 +267,12 @@ static const IMFS_mknod_controls _IMFS_mknod_controls = {
   #endif
 };
 
-static const IMFS_mount_data _Filesystem_Root_data = {
-  &_IMFS_fs_info,
-  &_IMFS_ops,
-  &_IMFS_mknod_controls
+static const IMFS_mount_data IMFS_root_mount_data = {
+  &IMFS_root_fs_info,
+  &IMFS_root_ops,
+  &IMFS_root_mknod_controls
 };
 
-#define _CONFIGURE_FILESYSTEM_ROOT_TYPE "/"
-
-#endif /* _CONFIGURE_USE_IMFS_AS_BASE_FILESYSTEM */
-
-#ifdef _CONFIGURE_FILESYSTEM_INITIALIZE
-
 #if defined(CONFIGURE_FILESYSTEM_DEVFS) \
   && !defined(CONFIGURE_FILESYSTEM_ENTRY_DEVFS)
   #define CONFIGURE_FILESYSTEM_ENTRY_DEVFS \
@@ -346,9 +322,7 @@ static const IMFS_mount_data _Filesystem_Root_data = {
 #endif
 
 const rtems_filesystem_table_t rtems_filesystem_table[] = {
-  #ifdef _CONFIGURE_USE_IMFS_AS_BASE_FILESYSTEM
-    { "/", IMFS_initialize_support },
-  #endif
+  { "/", IMFS_initialize_support },
   #ifdef CONFIGURE_FILESYSTEM_ENTRY_DEVFS
     CONFIGURE_FILESYSTEM_ENTRY_DEVFS,
   #endif
@@ -380,9 +354,9 @@ const rtems_filesystem_mount_configuration
 rtems_filesystem_root_configuration = {
   NULL,
   NULL,
-  _CONFIGURE_FILESYSTEM_ROOT_TYPE,
+  "/",
   RTEMS_FILESYSTEM_READ_WRITE,
-  &_Filesystem_Root_data
+  &IMFS_root_mount_data
 };
 
 RTEMS_SYSINIT_ITEM(
@@ -391,7 +365,7 @@ RTEMS_SYSINIT_ITEM(
   RTEMS_SYSINIT_ORDER_MIDDLE
 );
 
-#endif /* _CONFIGURE_FILESYSTEM_INITIALIZE */
+#endif /* !CONFIGURE_APPLICATION_DISABLE_FILESYSTEM */
 
 #ifndef CONFIGURE_MAXIMUM_FILE_DESCRIPTORS
   #define CONFIGURE_MAXIMUM_FILE_DESCRIPTORS 3
diff --git a/cpukit/include/rtems/confdefs/obsolete.h b/cpukit/include/rtems/confdefs/obsolete.h
index 50293bce23..4e85fb679f 100644
--- a/cpukit/include/rtems/confdefs/obsolete.h
+++ b/cpukit/include/rtems/confdefs/obsolete.h
@@ -65,6 +65,10 @@
   #error "The CONFIGURE_BDBUF_BUFFER_COUNT configuration option is obsolete since RTEMS 4.10.0"
 #endif
 
+#ifdef CONFIGURE_MAXIMUM_DEVICES
+  #warning "The CONFIGURE_MAXIMUM_DEVICES configuration option is obsolete since RTEMS 5.1"
+#endif
+
 #ifdef CONFIGURE_ENABLE_GO
   #warning "The CONFIGURE_ENABLE_GO configuration option is obsolete since RTEMS 5.1"
 #endif