Update README, TODO, and make some unfinished configuration options dependent on EXPERIMENTAL

3 files changed, 16 insertions, 1 deletions

diff --git a/nuttx/TODO b/nuttx/TODO
index 1739b618a..b202e9690 100644
--- a/nuttx/TODO
+++ b/nuttx/TODO
@@ -478,13 +478,23 @@ o Kernel/Protected Build
                address environment must be instantiated in memory to load the
                .text and .data and to allocate the initial user space components
                from the new user heap.
+
                However, the previous program's stack currently resides in its
                heap.  So when a process tries to run another program, its heap
                is unmapped and the system crashes.
+
                The fix is to add a separate stack in a separate memory region
                that does not get unmapped when creating new processes.  There
                are hooks in place to do this; I just need to get time to get
                that done.
+
+               UPDATE: I don't think it is that simple.  Startup logic will need
+               to access the new stack in its correct location to do things like
+               setup task arguments.  So I don't think that there is anyway to
+               do that without losing the current stack.
+
+               I may have to do the Linux solution:  Two stacks for each thread:
+               The main user stack, and a tiny kernel mode stack.
   Status:      Open
   Priority:    Pretty high... the kernel build is useless without this
                capability.
diff --git a/nuttx/arch/Kconfig b/nuttx/arch/Kconfig
index 6aaf1bac1..76daa1810 100644
--- a/nuttx/arch/Kconfig
+++ b/nuttx/arch/Kconfig
@@ -227,6 +227,7 @@ config ARCH_STACK_DYNAMIC
 	bool "Dynamic stack"
 	default n if !BUILD_KERNEL || !LIBC_EXECFUNCS
 	default y if BUILD_KERNEL && LIBC_EXECFUNCS
+	depends on EXPERIMENTAL
 	---help---
 		Select this option if the user process stack resides in its own
 		address space.  The naming of this selection implies that dynamic
diff --git a/nuttx/configs/sama5d4-ek/README.txt b/nuttx/configs/sama5d4-ek/README.txt
index d55935a2e..1c612e1b3 100644
--- a/nuttx/configs/sama5d4-ek/README.txt
+++ b/nuttx/configs/sama5d4-ek/README.txt
@@ -3944,6 +3944,10 @@ Configurations
        processes.  There are hooks in place to do this; I just need to get
        time to get that done.
 
+       To see the bug in action:
+
+         nsh> /bin/hello
+
   nsh:
 
     This configuration directory provide the NuttShell (NSH).  This is a
@@ -4416,7 +4420,7 @@ Configurations
    STATUS:
        See the To-Do list below
 
-   (2014-8-30): Retesting today I am seeing a strange behavior:  Serial
+   2014-8-30: Retesting today I am seeing a strange behavior:  Serial
        output is coming out in chunks with delays between the chunks.  It
        appears that something is not good in the serial port configuration.
        I see no such chunky behavior in, for example, grahics output.