The system call library can now be built with CONFIG_NUTTX_KERNEL. New select: CONFIG_LIB_SYSCALL

8 files changed, 84 insertions, 35 deletions

diff --git a/nuttx/Kconfig b/nuttx/Kconfig
index 7a5f41cba..4a84866cf 100644
--- a/nuttx/Kconfig
+++ b/nuttx/Kconfig
@@ -186,6 +186,7 @@ config PASS1_OBJECT
 config NUTTX_KERNEL
 	bool "NuttX kernel build"
 	default n
+	select LIB_SYSCALL
 	---help---
 		Builds NuttX as a separately compiled kernel.
 
@@ -681,9 +682,7 @@ endmenu
 
 menu "RTOS Features"
 source sched/Kconfig
-if NUTTX_KERNEL
 source syscall/Kconfig
-endif
 endmenu
 
 menu "Device Drivers"
diff --git a/nuttx/Makefile.unix b/nuttx/Makefile.unix
index b0e7cca7b..ec662a694 100644
--- a/nuttx/Makefile.unix
+++ b/nuttx/Makefile.unix
@@ -119,9 +119,7 @@ OTHERDIRS = lib
 
 ifeq ($(CONFIG_NUTTX_KERNEL),y)
 
-NONFSDIRS += syscall
-CONTEXTDIRS += syscall
-USERDIRS += syscall libc mm $(USER_ADDONS)
+USERDIRS += libc mm $(USER_ADDONS)
 ifeq ($(CONFIG_HAVE_CXX),y)
 USERDIRS += libxx
 endif
@@ -129,7 +127,7 @@ endif
 else
 
 NONFSDIRS += libc mm
-OTHERDIRS += syscall $(USER_ADDONS)
+OTHERDIRS += $(USER_ADDONS)
 ifeq ($(CONFIG_HAVE_CXX),y)
 NONFSDIRS += libxx
 else
@@ -138,6 +136,14 @@ endif
 
 endif
 
+ifeq ($(CONFIG_LIB_SYSCALL),y)
+NONFSDIRS += syscall
+CONTEXTDIRS += syscall
+USERDIRS += syscall
+else
+OTHERDIRS += syscall
+endif
+
 ifeq ($(CONFIG_NX),y)
 NONFSDIRS += graphics libnx
 CONTEXTDIRS += graphics libnx
diff --git a/nuttx/Makefile.win b/nuttx/Makefile.win
index 91aec195e..bc9cfcf58 100644
--- a/nuttx/Makefile.win
+++ b/nuttx/Makefile.win
@@ -112,9 +112,7 @@ OTHERDIRS = lib
 
 ifeq ($(CONFIG_NUTTX_KERNEL),y)
 
-NONFSDIRS += syscall
-CONTEXTDIRS += syscall
-USERDIRS += syscall libc mm $(USER_ADDONS)
+USERDIRS += libc mm $(USER_ADDONS)
 ifeq ($(CONFIG_HAVE_CXX),y)
 USERDIRS += libxx
 endif
@@ -122,7 +120,7 @@ endif
 else
 
 NONFSDIRS += libc mm
-OTHERDIRS += syscall $(USER_ADDONS)
+OTHERDIRS += $(USER_ADDONS)
 ifeq ($(CONFIG_HAVE_CXX),y)
 NONFSDIRS += libxx
 else
@@ -131,6 +129,14 @@ endif
 
 endif
 
+ifeq ($(CONFIG_LIB_SYSCALL),y)
+NONFSDIRS += syscall
+CONTEXTDIRS += syscall
+USERDIRS += syscall
+else
+OTHERDIRS += syscall
+endif
+
 ifeq ($(CONFIG_NX),y)
 NONFSDIRS += graphics libnx
 CONTEXTDIRS += graphics libnx
diff --git a/nuttx/arch/arm/src/armv6-m/svcall.h b/nuttx/arch/arm/src/armv6-m/svcall.h
index daa70a0c0..f5511c525 100644
--- a/nuttx/arch/arm/src/armv6-m/svcall.h
+++ b/nuttx/arch/arm/src/armv6-m/svcall.h
@@ -1,7 +1,7 @@
 /************************************************************************************
  * arch/arm/src/armv6-m/svcall.h
  *
- *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2013-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,7 +42,7 @@
 
 #include <nuttx/config.h>
 
-#ifdef CONFIG_NUTTX_KERNEL
+#ifdef CONFIG_LIB_SYSCALL
 #  include <syscall.h>
 #endif
 
@@ -55,11 +55,19 @@
  * syscall return.  The first four syscall values must be reserved.
  */
 
-#ifdef CONFIG_NUTTX_KERNEL
-#  ifndef CONFIG_SYS_RESERVED
-#    error "CONFIG_SYS_RESERVED must be defined to have the value 8"
-#  elif CONFIG_SYS_RESERVED != 8
-#    error "CONFIG_SYS_RESERVED must have the value 8"
+#ifdef CONFIG_LIB_SYSCALL
+#  ifdef CONFIG_NUTTX_KERNEL
+#    ifndef CONFIG_SYS_RESERVED
+#      error "CONFIG_SYS_RESERVED must be defined to have the value 8"
+#    elif CONFIG_SYS_RESERVED != 8
+#      error "CONFIG_SYS_RESERVED must have the value 8"
+#    endif
+#  else
+#    ifndef CONFIG_SYS_RESERVED
+#      error "CONFIG_SYS_RESERVED must be defined to have the value 3"
+#    elif CONFIG_SYS_RESERVED != 3
+#      error "CONFIG_SYS_RESERVED must have the value 3"
+#    endif
 #  endif
 #endif
 
diff --git a/nuttx/arch/arm/src/armv6-m/up_svcall.c b/nuttx/arch/arm/src/armv6-m/up_svcall.c
index 1b367259b..ad9da62d4 100644
--- a/nuttx/arch/arm/src/armv6-m/up_svcall.c
+++ b/nuttx/arch/arm/src/armv6-m/up_svcall.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/arm/src/armv6-m/up_svcall.c
  *
- *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2013-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -47,7 +47,7 @@
 #include <arch/irq.h>
 #include <nuttx/sched.h>
 
-#ifdef CONFIG_NUTTX_KERNEL
+#ifdef CONFIG_LIB_SYSCALL
 #  include <syscall.h>
 #endif
 
@@ -119,7 +119,7 @@
  *
  ****************************************************************************/
 
-#ifdef CONFIG_NUTTX_KERNEL
+#ifdef CONFIG_LIB_SYSCALL
 static void dispatch_syscall(void) naked_function;
 static void dispatch_syscall(void)
 {
@@ -444,7 +444,7 @@ int up_svcall(int irq, FAR void *context)
 
       default:
         {
-#ifdef CONFIG_NUTTX_KERNEL
+#ifdef CONFIG_LIB_SYSCALL
           FAR struct tcb_s *rtcb = sched_self();
           int index = rtcb->xcp.nsyscalls;
 
diff --git a/nuttx/arch/arm/src/armv7-m/svcall.h b/nuttx/arch/arm/src/armv7-m/svcall.h
index 2c4735335..64c4bdfe8 100644
--- a/nuttx/arch/arm/src/armv7-m/svcall.h
+++ b/nuttx/arch/arm/src/armv7-m/svcall.h
@@ -1,7 +1,7 @@
 /************************************************************************************
  * arch/arm/src/armv7-m/svcall.h
  *
- *   Copyright (C) 2011, 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011, 2013-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,7 +42,7 @@
 
 #include <nuttx/config.h>
 
-#ifdef CONFIG_NUTTX_KERNEL
+#ifdef CONFIG_LIB_SYSCALL
 #  include <syscall.h>
 #endif
 
@@ -55,11 +55,19 @@
  * syscall return.  The first four syscall values must be reserved.
  */
 
-#ifdef CONFIG_NUTTX_KERNEL
-#  ifndef CONFIG_SYS_RESERVED
-#    error "CONFIG_SYS_RESERVED must be defined to have the value 8"
-#  elif CONFIG_SYS_RESERVED != 8
-#    error "CONFIG_SYS_RESERVED must have the value 8"
+#ifdef CONFIG_LIB_SYSCALL
+#  ifdef CONFIG_NUTTX_KERNEL
+#    ifndef CONFIG_SYS_RESERVED
+#      error "CONFIG_SYS_RESERVED must be defined to have the value 8"
+#    elif CONFIG_SYS_RESERVED != 8
+#      error "CONFIG_SYS_RESERVED must have the value 8"
+#    endif
+#  else
+#    ifndef CONFIG_SYS_RESERVED
+#      error "CONFIG_SYS_RESERVED must be defined to have the value 3"
+#    elif CONFIG_SYS_RESERVED != 3
+#      error "CONFIG_SYS_RESERVED must have the value 3"
+#    endif
 #  endif
 #endif
 
diff --git a/nuttx/arch/arm/src/armv7-m/up_svcall.c b/nuttx/arch/arm/src/armv7-m/up_svcall.c
index be33b675d..9909057d3 100644
--- a/nuttx/arch/arm/src/armv7-m/up_svcall.c
+++ b/nuttx/arch/arm/src/armv7-m/up_svcall.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/arm/src/armv7-m/up_svcall.c
  *
- *   Copyright (C) 2009, 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009, 2011-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -47,7 +47,7 @@
 #include <arch/irq.h>
 #include <nuttx/sched.h>
 
-#ifdef CONFIG_NUTTX_KERNEL
+#ifdef CONFIG_LIB_SYSCALL
 #  include <syscall.h>
 #endif
 
@@ -116,7 +116,7 @@
  *
  ****************************************************************************/
 
-#ifdef CONFIG_NUTTX_KERNEL
+#ifdef CONFIG_LIB_SYSCALL
 static void dispatch_syscall(void) naked_function;
 static void dispatch_syscall(void)
 {
@@ -443,7 +443,7 @@ int up_svcall(int irq, FAR void *context)
 
       default:
         {
-#ifdef CONFIG_NUTTX_KERNEL
+#ifdef CONFIG_LIB_SYSCALL
           FAR struct tcb_s *rtcb = sched_self();
           int index = rtcb->xcp.nsyscalls;
 
diff --git a/nuttx/syscall/Kconfig b/nuttx/syscall/Kconfig
index 0c5b74ab1..f1138611a 100644
--- a/nuttx/syscall/Kconfig
+++ b/nuttx/syscall/Kconfig
@@ -3,9 +3,31 @@
 # see misc/tools/kconfig-language.txt.
 #
 
-if NUTTX_KERNEL
+menuconfig LIB_SYSCALL
+	bool "System call support"
+	default n
+	---help---
+		Build in support for "system calls".  System calls are used to
+		implement a call gate mechanism that can be be used to call from
+		user code into the kernel.  This is only useful for user code that
+		likes outside of the kernel such as when the NUTTX_KERNEL build is
+		selected.
+
+		This permits calls from user-mode code into kernel mode; the call
+		gate will change the mode of operation from user to supervisor mode,
+		then call into the OS code on behalf of the user-mode application.
+
+		If if there are no privilege issues preventing the call, system
+		calls may also be of value because it can eliminate the need for
+		symbol tables when linking external modules to the NuttX base code.
+		The selection will build libsyscall.  External modules can then link
+		with libsyscall when they are built and they can call into the OS
+		with no knowledge of the actual address in the OS.  In this case,
+		they call into a proxy that is link with the external code; that
+		proxy then marshals the call parameter and invokes the system call
+		to accomplish the interface.
 
-comment "System call configuration"
+if LIB_SYSCALL
 
 config SYS_RESERVED
 	int "Number of reserved system calls"
@@ -34,4 +56,4 @@ config SYS_NNEST
 		space memory.  So it is expected that the maximum nesting level will
 		be only 2.
 
-endif
+endif # LIB_SYSCALL