diff --git a/nuttx/Kconfig b/nuttx/Kconfig
index 13e92ebf2c..239a791fa2 100644
--- a/nuttx/Kconfig
+++ b/nuttx/Kconfig
@@ -45,22 +45,30 @@ choice
 
 config WINDOWS_NATIVE
 	bool "Windows Native"
+	---help---
+		Build natively in a CMD.exe environment with Windows style paths (like C:\cgywin\home)
 
 config WINDOWS_CYGWIN
 	bool "Cygwin"
+-	--help---
+		Build natively in a Cygwin environment with POSIX style paths (like /cygdrive/c/cgywin/home)
 
 config WINDOWS_MSYS
 	bool "MSYS"
+	---help---
+		Build natively in a Cygwin environment with POSIX style paths (like /cygdrive/c/cgywin/home)
 
 config WINDOWS_OTHER
-	bool "Other POSIX-like environment"
+	bool "Windows POSIX-like environment"
+	---help---
+		Build natively in another POSIX-like environment.  Additional support may be necessary
 
 endchoice
 
 config WINDOWS_MKLINK
 	bool "Use mklink"
 	default y
-	depends on HOST_WINDOWS
+	depends on WINDOWS_NATIVE
 	---help---
 		Use the mklink command to set up symbolic links when NuttX is
 		configured.  Otherwise, configuration directories will be copied to
diff --git a/nuttx/arch/arm/src/lm3s/Kconfig b/nuttx/arch/arm/src/lm3s/Kconfig
index 03da5c458a..ef33655f55 100644
--- a/nuttx/arch/arm/src/lm3s/Kconfig
+++ b/nuttx/arch/arm/src/lm3s/Kconfig
@@ -28,20 +28,25 @@ config ARCH_CHIP_LM3S8962
 endchoice
 
 choice
-	prompt "Toolchain"
-	default LM3S_BUILDROOT
+	prompt "Toolchain Selection"
+	default LM3S_BUILDROOT if !HOST_WINDOWS
+	default LM3S_CODESOURCERYW if HOST_WINDOWS
 
 config LM3S_CODESOURCERYW
 	bool "CodeSourcery GNU toolchain under Windows"
+	depends on HOST_WINDOWS
 
 config LM3S_CODESOURCERYL
 	bool "CodeSourcery GNU toolchain under Linux"
+	depends on HOST_LINUX
 
 config LM3S_DEVKITARM
 	bool "devkitARM GNU toolchain"
+	depends on HOST_WINDOWS
 
 config LM3S_BUILDROOT
 	bool "Buildroot"
+	depends on !WINDOWS_NATIVE
 
 endchoice
 
diff --git a/nuttx/arch/arm/src/lpc17xx/Kconfig b/nuttx/arch/arm/src/lpc17xx/Kconfig
index 2769fc231f..8a12ad9023 100644
--- a/nuttx/arch/arm/src/lpc17xx/Kconfig
+++ b/nuttx/arch/arm/src/lpc17xx/Kconfig
@@ -58,26 +58,33 @@ config ARCH_FAMILY_LPC176X
 
 choice
 	prompt "Toolchain Selection"
-	default LPC17_CODESOURCERYW
+	default LPC17_BUILDROOT if !HOST_WINDOWS
+	default LPC17_CODESOURCERYW if HOST_WINDOWS
 	depends on ARCH_CHIP_LPC17XX
 
 config LPC17_CODESOURCERYW
-	bool "CodeSourcery for Windows"
+	bool "CodeSourcery GNU toolchain under Windows"
+	depends on HOST_WINDOWS
 
 config LPC17_CODESOURCERYL
-	bool "CodeSourcery for Linux"
+	bool "CodeSourcery GNU toolchain under Linux"
+	depends on HOST_LINUX
 
 config LPC17_DEVKITARM
-	bool "DevkitARM (Windows)"
+	bool "devkitARM GNU toolchain"
+	depends on HOST_WINDOWS
 
 config LPC17_BUILDROOT
-	bool "NuttX buildroot (Cygwin or Linux)"
+	bool "Buildroot"
+	depends on !WINDOWS_NATIVE
 
 config LPC17_CODEREDW
 	bool "CodeRed for Windows"
+	depends on HOST_WINDOWS
 
 config LPC17_CODEREDL
 	bool "CodeRed for Windows"
+	depends on HOST_LINUX
 
 endchoice
 
diff --git a/nuttx/arch/arm/src/lpc31xx/Kconfig b/nuttx/arch/arm/src/lpc31xx/Kconfig
index 39b19b95d5..ad7bf3d4ed 100644
--- a/nuttx/arch/arm/src/lpc31xx/Kconfig
+++ b/nuttx/arch/arm/src/lpc31xx/Kconfig
@@ -26,20 +26,25 @@ endchoice
 
 choice
 	prompt "Toolchain Selection"
-	default LPC31_CODESOURCERYW
+	default LPC31_BUILDROOT if !HOST_WINDOWS
+	default LPC31_CODESOURCERYW if HOST_WINDOWS
 	depends on ARCH_CHIP_LPC31XX
 
 config LPC31_CODESOURCERYW
-	bool "CodeSourcery for Windows"
+	bool "CodeSourcery GNU toolchain under Windows"
+	depends on HOST_WINDOWS
 
 config LPC31_CODESOURCERYL
-	bool "CodeSourcery for Linux"
+	bool "CodeSourcery GNU toolchain under Linux"
+	depends on HOST_LINUX
 
 config LPC31_DEVKITARM
-	bool "DevkitARM (Windows)"
+	bool "devkitARM GNU toolchain"
+	depends on HOST_WINDOWS
 
 config LPC31_BUILDROOT
-	bool "NuttX buildroot (Cygwin or Linux)"
+	bool "Buildroot"
+	depends on !WINDOWS_NATIVE
 
 endchoice
 
diff --git a/nuttx/arch/arm/src/stm32/Kconfig b/nuttx/arch/arm/src/stm32/Kconfig
index a0e3fab0c6..81ba9e4a37 100644
--- a/nuttx/arch/arm/src/stm32/Kconfig
+++ b/nuttx/arch/arm/src/stm32/Kconfig
@@ -195,29 +195,37 @@ config STM32_STM32F40XX
 
 choice
 	prompt "Toolchain Selection"
-	default STM32_CODESOURCERYW
+	default LPC31_BUILDROOT if !HOST_WINDOWS
+	default STM32_CODESOURCERYW if HOST_WINDOWS
 	depends on ARCH_CHIP_STM32
 
 config STM32_CODESOURCERYW
-	bool "CodeSourcery for Windows"
+	bool "CodeSourcery GNU toolchain under Windows"
+	depends on HOST_WINDOWS
 
 config STM32_CODESOURCERYL
-	bool "CodeSourcery for Linux"
+	bool "CodeSourcery GNU toolchain under Linux"
+	depends on HOST_LINUX
 
 config STM32_ATOLLIC_LITE
 	bool "Atollic Lite for Windows"
+	depends on HOST_WINDOWS
 
 config STM32_ATOLLIC_PRO
 	bool "Atollic Pro for Windows"
+	depends on HOST_WINDOWS
 
 config STM32_DEVKITARM
-	bool "DevkitARM (Windows)"
+	bool "devkitARM GNU toolchain"
+	depends on HOST_WINDOWS
 
 config STM32_RAISONANCE
 	bool "STMicro Raisonance for Windows"
+	depends on HOST_WINDOWS
 
 config STM32_BUILDROOT
-	bool "NuttX buildroot (Cygwin or Linux)"
+	bool "Buildroot (Cygwin or Linux)"
+	depends on !WINDOWS_NATIVE
 
 endchoice
 
diff --git a/nuttx/configs/ea3131/README.txt b/nuttx/configs/ea3131/README.txt
index 29b68ce8d1..2912bf3187 100644
--- a/nuttx/configs/ea3131/README.txt
+++ b/nuttx/configs/ea3131/README.txt
@@ -77,9 +77,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/eagle100/README.txt b/nuttx/configs/eagle100/README.txt
index 79a4b96fdf..a79ac2b2d7 100644
--- a/nuttx/configs/eagle100/README.txt
+++ b/nuttx/configs/eagle100/README.txt
@@ -66,9 +66,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the CodeSourcery toolchain.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/ekk-lm3s9b96/README.txt b/nuttx/configs/ekk-lm3s9b96/README.txt
index fc9448aaf9..d331c1cd56 100644
--- a/nuttx/configs/ekk-lm3s9b96/README.txt
+++ b/nuttx/configs/ekk-lm3s9b96/README.txt
@@ -136,9 +136,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/fire-stm32v2/README.txt b/nuttx/configs/fire-stm32v2/README.txt
index aa3225524b..88b5bf583b 100644
--- a/nuttx/configs/fire-stm32v2/README.txt
+++ b/nuttx/configs/fire-stm32v2/README.txt
@@ -226,9 +226,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   The CodeSourcery Toolchain (2009q1)
diff --git a/nuttx/configs/hymini-stm32v/README.txt b/nuttx/configs/hymini-stm32v/README.txt
index 4c55458061..9b063d0ffa 100644
--- a/nuttx/configs/hymini-stm32v/README.txt
+++ b/nuttx/configs/hymini-stm32v/README.txt
@@ -80,9 +80,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/kwikstik-k40/README.txt b/nuttx/configs/kwikstik-k40/README.txt
index 1f3873cc9e..98e738d803 100644
--- a/nuttx/configs/kwikstik-k40/README.txt
+++ b/nuttx/configs/kwikstik-k40/README.txt
@@ -204,9 +204,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/lincoln60/README.txt b/nuttx/configs/lincoln60/README.txt
index 87847cd8b7..159753890e 100644
--- a/nuttx/configs/lincoln60/README.txt
+++ b/nuttx/configs/lincoln60/README.txt
@@ -104,9 +104,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/lm3s6432-s2e/README.txt b/nuttx/configs/lm3s6432-s2e/README.txt
index df7e7029d3..296a10f054 100644
--- a/nuttx/configs/lm3s6432-s2e/README.txt
+++ b/nuttx/configs/lm3s6432-s2e/README.txt
@@ -131,9 +131,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/lm3s6965-ek/README.txt b/nuttx/configs/lm3s6965-ek/README.txt
index 96e87bb272..1e3aed2d95 100644
--- a/nuttx/configs/lm3s6965-ek/README.txt
+++ b/nuttx/configs/lm3s6965-ek/README.txt
@@ -160,9 +160,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/lm3s8962-ek/README.txt b/nuttx/configs/lm3s8962-ek/README.txt
index 6de30047b0..fdb7834660 100644
--- a/nuttx/configs/lm3s8962-ek/README.txt
+++ b/nuttx/configs/lm3s8962-ek/README.txt
@@ -160,9 +160,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/lpc4330-xplorer/README.txt b/nuttx/configs/lpc4330-xplorer/README.txt
index f7ec778eec..65f3820099 100644
--- a/nuttx/configs/lpc4330-xplorer/README.txt
+++ b/nuttx/configs/lpc4330-xplorer/README.txt
@@ -185,9 +185,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   The CodeSourcery Toolchain (2009q1)
diff --git a/nuttx/configs/lpcxpresso-lpc1768/README.txt b/nuttx/configs/lpcxpresso-lpc1768/README.txt
index 2fedefc588..ca0c0fdbd6 100644
--- a/nuttx/configs/lpcxpresso-lpc1768/README.txt
+++ b/nuttx/configs/lpcxpresso-lpc1768/README.txt
@@ -288,9 +288,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/mbed/README.txt b/nuttx/configs/mbed/README.txt
index 09763086bd..a5390a1d74 100644
--- a/nuttx/configs/mbed/README.txt
+++ b/nuttx/configs/mbed/README.txt
@@ -74,9 +74,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/mcu123-lpc214x/README.txt b/nuttx/configs/mcu123-lpc214x/README.txt
index 49a6d5c0f7..435f8647d4 100644
--- a/nuttx/configs/mcu123-lpc214x/README.txt
+++ b/nuttx/configs/mcu123-lpc214x/README.txt
@@ -72,9 +72,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the CodeSourcery toolchain.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) may not work with default optimization
diff --git a/nuttx/configs/micropendous3/README.txt b/nuttx/configs/micropendous3/README.txt
index cc4a47ee3e..583f1d8d8a 100644
--- a/nuttx/configs/micropendous3/README.txt
+++ b/nuttx/configs/micropendous3/README.txt
@@ -265,10 +265,6 @@ Windows Native Toolchains
      is because the dependencies are generated using Windows pathes which do
      not work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native
-     toolchains.  That support can be enabled by modifying your Make.defs
-     file as follows:
-
        MKDEP = $(TOPDIR)/tools/mknulldeps.sh
 
   An additional issue with the WinAVR toolchain, in particular, is that it
diff --git a/nuttx/configs/mirtoo/README.txt b/nuttx/configs/mirtoo/README.txt
index 7a58572bf8..e0b7dc3bc8 100644
--- a/nuttx/configs/mirtoo/README.txt
+++ b/nuttx/configs/mirtoo/README.txt
@@ -448,9 +448,6 @@ Toolchains
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
 Loading NuttX with ICD3
diff --git a/nuttx/configs/ntosd-dm320/README.txt b/nuttx/configs/ntosd-dm320/README.txt
index ba6cc87ecb..1a6a38e7ca 100644
--- a/nuttx/configs/ntosd-dm320/README.txt
+++ b/nuttx/configs/ntosd-dm320/README.txt
@@ -96,9 +96,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/nucleus2g/README.txt b/nuttx/configs/nucleus2g/README.txt
index 0d1d2896b1..e915e8bdd0 100644
--- a/nuttx/configs/nucleus2g/README.txt
+++ b/nuttx/configs/nucleus2g/README.txt
@@ -134,9 +134,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/olimex-lpc1766stk/README.txt b/nuttx/configs/olimex-lpc1766stk/README.txt
index 6bb36f40ce..ec7ddd42db 100644
--- a/nuttx/configs/olimex-lpc1766stk/README.txt
+++ b/nuttx/configs/olimex-lpc1766stk/README.txt
@@ -222,9 +222,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/olimex-strp711/README.txt b/nuttx/configs/olimex-strp711/README.txt
index 7c3d3fe5b3..17f24734a6 100644
--- a/nuttx/configs/olimex-strp711/README.txt
+++ b/nuttx/configs/olimex-strp711/README.txt
@@ -157,9 +157,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the CodeSourcery toolchain.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) may not work with default optimization
diff --git a/nuttx/configs/pcblogic-pic32mx/README.txt b/nuttx/configs/pcblogic-pic32mx/README.txt
index 9eea61fd87..bd81f0c423 100644
--- a/nuttx/configs/pcblogic-pic32mx/README.txt
+++ b/nuttx/configs/pcblogic-pic32mx/README.txt
@@ -276,9 +276,6 @@ Toolchains
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
 Loading NuttX with PICkit2
diff --git a/nuttx/configs/pic32-starterkit/README.txt b/nuttx/configs/pic32-starterkit/README.txt
index b21066b535..ea82a166b2 100644
--- a/nuttx/configs/pic32-starterkit/README.txt
+++ b/nuttx/configs/pic32-starterkit/README.txt
@@ -493,9 +493,6 @@ Toolchains
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
 Powering the Board
diff --git a/nuttx/configs/pic32mx7mmb/README.txt b/nuttx/configs/pic32mx7mmb/README.txt
index cc8ea5573c..2112065255 100644
--- a/nuttx/configs/pic32mx7mmb/README.txt
+++ b/nuttx/configs/pic32mx7mmb/README.txt
@@ -261,9 +261,6 @@ Toolchains
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
 Powering the Board
diff --git a/nuttx/configs/sam3u-ek/README.txt b/nuttx/configs/sam3u-ek/README.txt
index bcb8b9ef62..d8d1908046 100644
--- a/nuttx/configs/sam3u-ek/README.txt
+++ b/nuttx/configs/sam3u-ek/README.txt
@@ -75,9 +75,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/shenzhou/README.txt b/nuttx/configs/shenzhou/README.txt
index 2f2833bbee..a15d2f9152 100644
--- a/nuttx/configs/shenzhou/README.txt
+++ b/nuttx/configs/shenzhou/README.txt
@@ -249,9 +249,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   The CodeSourcery Toolchain (2009q1)
diff --git a/nuttx/configs/stm3210e-eval/README.txt b/nuttx/configs/stm3210e-eval/README.txt
index 9e63112016..f494e9e9ab 100644
--- a/nuttx/configs/stm3210e-eval/README.txt
+++ b/nuttx/configs/stm3210e-eval/README.txt
@@ -83,9 +83,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/stm3220g-eval/README.txt b/nuttx/configs/stm3220g-eval/README.txt
index 0e6a9a7dad..1e3388e70d 100644
--- a/nuttx/configs/stm3220g-eval/README.txt
+++ b/nuttx/configs/stm3220g-eval/README.txt
@@ -89,9 +89,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   The CodeSourcery Toolchain (2009q1)
diff --git a/nuttx/configs/stm3240g-eval/README.txt b/nuttx/configs/stm3240g-eval/README.txt
index 140cc7414d..829f3a7773 100644
--- a/nuttx/configs/stm3240g-eval/README.txt
+++ b/nuttx/configs/stm3240g-eval/README.txt
@@ -91,9 +91,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   The CodeSourcery Toolchain (2009q1)
diff --git a/nuttx/configs/stm32f100rc_generic/README.txt b/nuttx/configs/stm32f100rc_generic/README.txt
index 0c96d4fbc5..951fb31305 100644
--- a/nuttx/configs/stm32f100rc_generic/README.txt
+++ b/nuttx/configs/stm32f100rc_generic/README.txt
@@ -85,9 +85,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   The CodeSourcery Toolchain (2009q1)
diff --git a/nuttx/configs/stm32f4discovery/README.txt b/nuttx/configs/stm32f4discovery/README.txt
index 68be0a8a67..eb43cad27e 100644
--- a/nuttx/configs/stm32f4discovery/README.txt
+++ b/nuttx/configs/stm32f4discovery/README.txt
@@ -89,9 +89,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   The CodeSourcery Toolchain (2009q1)
diff --git a/nuttx/configs/stm32f4discovery/ostest/Make.defs b/nuttx/configs/stm32f4discovery/ostest/Make.defs
index 6ed8530ad2..614e0c456f 100644
--- a/nuttx/configs/stm32f4discovery/ostest/Make.defs
+++ b/nuttx/configs/stm32f4discovery/ostest/Make.defs
@@ -172,4 +172,9 @@ HOSTCC = gcc
 HOSTINCLUDES = -I.
 HOSTCFLAGS = -Wall -Wstrict-prototypes -Wshadow -g -pipe
 HOSTLDFLAGS =
+ifeq ($(CONFIG_HOST_WINDOWS),y)
+  HOSTEXEEXT = .exe
+else
+  HOSTEXEEXT =
+endif
 
diff --git a/nuttx/configs/sure-pic32mx/README.txt b/nuttx/configs/sure-pic32mx/README.txt
index 68f0bd3365..403fe42baf 100644
--- a/nuttx/configs/sure-pic32mx/README.txt
+++ b/nuttx/configs/sure-pic32mx/README.txt
@@ -342,9 +342,6 @@ Toolchains
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
 Loading NuttX with PICkit2
diff --git a/nuttx/configs/teensy/README.txt b/nuttx/configs/teensy/README.txt
index 454a42d054..30349e1ff0 100644
--- a/nuttx/configs/teensy/README.txt
+++ b/nuttx/configs/teensy/README.txt
@@ -268,10 +268,6 @@ Windows Native Toolchains
      is because the dependencies are generated using Windows pathes which do
      not work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native
-     toolchains.  That support can be enabled by modifying your Make.defs
-     file as follows:
-
        MKDEP = $(TOPDIR)/tools/mknulldeps.sh
 
   An additional issue with the WinAVR toolchain, in particular, is that it
diff --git a/nuttx/configs/twr-k60n512/README.txt b/nuttx/configs/twr-k60n512/README.txt
index cd567fd375..a9db7a1f77 100644
--- a/nuttx/configs/twr-k60n512/README.txt
+++ b/nuttx/configs/twr-k60n512/README.txt
@@ -341,9 +341,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/configs/ubw32/README.txt b/nuttx/configs/ubw32/README.txt
index 83ade7dae9..801be39a9a 100644
--- a/nuttx/configs/ubw32/README.txt
+++ b/nuttx/configs/ubw32/README.txt
@@ -287,9 +287,6 @@ Toolchains
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
 Loading NuttX with PICkit2
diff --git a/nuttx/configs/vsn/README.txt b/nuttx/configs/vsn/README.txt
index a0b8e24193..debc3e8ad4 100644
--- a/nuttx/configs/vsn/README.txt
+++ b/nuttx/configs/vsn/README.txt
@@ -80,9 +80,6 @@ GNU Toolchain Options
      because the dependencies are generated using Windows pathes which do not
      work with the Cygwin make.
 
-     Support has been added for making dependencies with the windows-native toolchains.
-     That support can be enabled by modifying your Make.defs file as follows:
-
        MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
 
   NOTE 1: The CodeSourcery toolchain (2009q1) does not work with default optimization
diff --git a/nuttx/tools/README.txt b/nuttx/tools/README.txt
index 28fa664bda..3c9730d001 100644
--- a/nuttx/tools/README.txt
+++ b/nuttx/tools/README.txt
@@ -290,11 +290,17 @@ mknulldeps.sh
 
   The mknulldeps.sh is a stub script that does essentially nothing.
 
-  NOTE:  The mkdep.* files are undergoing change.  mkdeps.sh is a bash
+  NOTE:  The mk*deps.* files are undergoing change.  mkdeps.sh is a bash
   script that produces dependencies well for POSIX style hosts (e..g.,
   Linux and Cygwin).  It does not work well for mixed environments with
   a Windows toolchain running in a POSIX style environemnt (hence, the
-  mknulldeps.sh script).
+  mknulldeps.sh script).  And, of course, cannot be used in a Windows
+  nativ environment.
+
+  [mkdeps.sh does have an option, --winpath, that purports to convert
+  the dependencies generated by a Windows toolchain to POSIX format.
+  However, that is not being used and mostly likely does not cover
+  all of the conversion cases.]
 
   mkdeps.bat is a simple port of the bash script to run in a Windows
   command shell.  However, it does not work well either because some
@@ -302,8 +308,13 @@ mknulldeps.sh
   by the CMD.exe shell.
 
   mkdeps.c generates mkdeps (on Linux) or mkdeps.exe (on Windows).
-  This C version should solve all of the issues.  However, this verison
-  is still under-development.
+  However, this verison is still under-development.  It works well in
+  the all POSIX environment or in the all Windows environment but also
+  does not work well in mixed POSIX environment with a Windows toolchain.
+  In that case, there are still issues with the conversion of things like
+  'c:\Program Files' to 'c:program files' by bash.  Those issues may,
+  eventually be solvable but for now continue to use mknulldeps.sh in
+  that mixed environment.
 
 define.sh
 
diff --git a/nuttx/tools/mkdeps.c b/nuttx/tools/mkdeps.c
index 7850cee732..f2a1963878 100644
--- a/nuttx/tools/mkdeps.c
+++ b/nuttx/tools/mkdeps.c
@@ -396,7 +396,8 @@ static void do_dependency(const char *file, char separator)
       ret = system(command);
       if (ret != 0)
         {
-          fprintf(stderr, "ERROR: ssystem(%s) failed\n", command);
+          fprintf(stderr, "ERROR: system failed: %s\n", strerror(errno));
+          fprintf(stderr, "       command: %s\n", command);
           exit(EXIT_FAILURE);
         }