Update TODO list

TODO

@@ -1,4 +1,4 @@
-NuttX TODO List (Last updated July 1, 2019)
+NuttX TODO List (Last updated August 18, 2019)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 This file summarizes known NuttX bugs, limitations, inconsistencies with
@@ -16,7 +16,7 @@ nuttx/:
   (5)  Signals (sched/signal, arch/)
   (2)  pthreads (sched/pthread, libs/libc/pthread)
   (0)  Message Queues (sched/mqueue)
-  (9)  Kernel/Protected Build
+ (10)  Kernel/Protected Build
   (3)  C++ Support
   (5)  Binary loaders (binfmt/)
  (17)  Network (net/, drivers/net)
@@ -1121,6 +1121,50 @@ o Kernel/Protected Build
                may host malicious code.  Very low for the typical FLAT build,
                however.
 
+  Title:       NSH BUILTIN TASKS DO NOT WORK IN PROTECTED MODE
+  Description: In the PROTECTED build mode, NSH built-in commands do not
+               work.  The current NSH builtin implementation violates the
+               POSIX interface layer, it calls directly into the
+               nuttx/binfmt logic which is not possible in the protected
+               mode.
+
+               Currently, support for CONFIG_BUILTIN is is disabled for
+               PROTECTED mode  in in nuttx/binfmt/Kconfig:
+
+                  config BUILTIN
+                          bool "Support Builtin Applications"
+                          default n
+                          depends on (!BUILD_PROTECTED && !BUILD_KERNEL) || EXPERIMENTAL
+
+               And that disables section of the option apps/nshlib/Kconfig:
+
+                  config NSH_BUILTIN_APPS
+                          bool "Enable built-in applications"
+                         default n
+                          depends on BUILTIN
+
+               So if CONFIG_BUILD_PROTECTED is set, then CONFIG_BUILTIN
+               cannot be set.  And if CONFIG_BUILTIN is not set, then
+               builtin applications will not be supported.
+
+               The solution appears woulld seem to be:  (1) Move the problem
+               code out of nuttx/binfmt and into libs/binfmt so that it is
+               available both to the kernel code and to the application
+               code.  And to remove the dependency on !BUILD_PROTECTED from
+               binfmt/Kconfig.
+
+               NOTE:  NSH builtins cannot be supported under any condition
+               in the KERNEL build.  In that build, only file-based
+               applications can be supported.  But that is a different story.
+  Status:      Open
+  Priority:    Medium.  Higher if you need builtin application support in
+               protected mode.
+
+This really belongs in the TODO list.
+
+Greg
+
+
 o C++ Support
   ^^^^^^^^^^^
 
@@ -2708,6 +2752,9 @@ o Network Utilities (apps/netutils/)
 o NuttShell (NSH) (apps/nshlib)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+  Related:  See "NSH BUILTIN TASKS DO NOT WORK IN PROTECTED MODE" under
+  the heading Kernel/Protected Build.
+
   Title:       IFCONFIG AND MULTIPLE NETWORK INTERFACES
   Description: The ifconfig command will not behave correctly if an interface
                is provided and there are multiple interfaces.  It should only