From 0effe359100318f343c3775be321924dbe1d11ee Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Sat, 30 Aug 2014 08:48:18 -0600
Subject: [PATCH] Enable SYSCALL interface with address environments in the
 SAMA5D4-EK ELF configuration

---
 configs/sama5d4-ek/README.txt    | 14 +++++++++++++-
 configs/sama5d4-ek/elf/defconfig |  5 ++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/configs/sama5d4-ek/README.txt b/configs/sama5d4-ek/README.txt
index 7fad01b809..b9cb114c06 100644
--- a/configs/sama5d4-ek/README.txt
+++ b/configs/sama5d4-ek/README.txt
@@ -3701,9 +3701,19 @@ Configurations
         CONFIG_GRAN=n                          : Disable the granule allocator 
         CONFIG_MM_PGALLOC=n                    : Disable the page allocator
 
+    4. A system call interface is enabled and the ELF test programs interface with the base RTOS code system calls.  This eliminates the need for symbol tables to link with the base RTOS (symbol tables are still used, however, to interface with the common C library instaniation).  Relevant configuration settings:
+
+    RTOS Features -> System call support
+      CONFIG_LIB_SYSCALL=y                      : Enable system call support
+      CONFIG_SYS_NNEST=2                        : Max number of nested system calls
+      CONFIG_SYS_RESERVED=1                     : SYStem call 0 is reserved on this platform
+
+    Application Configurations -> Examples -> ELF Loader Example
+      CONFIG_EXAMPLES_ELF_SYSCALL=y             : Link apps with the SYStem call library
+
     STATUS:
       2014-8-24: This configuration works with the address environment
-                 option disable.
+                 and system call options disabled.
       2014-8-28: Now this option works well well with address environments
                  enabled.  There is a potential issue with the use of
                  task_create() as it is used in the ELF test, but the code
@@ -3711,6 +3721,8 @@ Configurations
 
                  http://www.nuttx.org/doku.php?id=wiki:nxinternal:memconfigs#task_create
 
+      2014-8-29: System call interface verified.
+
   nsh:
 
     This configuration directory provide the NuttShell (NSH).  This is a
diff --git a/configs/sama5d4-ek/elf/defconfig b/configs/sama5d4-ek/elf/defconfig
index f22da29fbd..b877cb3cdc 100644
--- a/configs/sama5d4-ek/elf/defconfig
+++ b/configs/sama5d4-ek/elf/defconfig
@@ -427,7 +427,9 @@ CONFIG_IDLETHREAD_STACKSIZE=1024
 CONFIG_USERMAIN_STACKSIZE=2048
 CONFIG_PTHREAD_STACK_MIN=256
 CONFIG_PTHREAD_STACK_DEFAULT=2048
-# CONFIG_LIB_SYSCALL is not set
+CONFIG_LIB_SYSCALL=y
+CONFIG_SYS_RESERVED=1
+CONFIG_SYS_NNEST=2
 
 #
 # Device Drivers
@@ -701,6 +703,7 @@ CONFIG_BUILTIN_PROXY_STACKSIZE=1024
 # CONFIG_EXAMPLES_CXXTEST is not set
 # CONFIG_EXAMPLES_DHCPD is not set
 CONFIG_EXAMPLES_ELF=y
+CONFIG_EXAMPLES_ELF_SYSCALL=y
 # CONFIG_EXAMPLES_ELF_LIBC is not set
 CONFIG_EXAMPLES_ELF_DEVMINOR=0
 CONFIG_EXAMPLES_ELF_DEVPATH="/dev/ram0"