Add env vars describing U-Boot target board

This can be useful for generic scripts. For example, rather than hard-
coding a script to ext2load tegra-harmony.dtb, it could load
${soc}-${board}.dtb and hence not need adjustments to run on multiple
boards.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/README b/README
index bb1b725..dac46f3 100644
--- a/README
+++ b/README
@@ -2229,6 +2229,20 @@
 		the environment like the "source" command or the
 		boot command first.
 
+		CONFIG_ENV_VARS_UBOOT_CONFIG
+
+		Define this in order to add variables describing the
+		U-Boot build configuration to the default environment.
+		These will be named arch, cpu, board, vendor, and soc.
+
+		Enabling this option will cause the following to be defined:
+
+		- CONFIG_SYS_ARCH
+		- CONFIG_SYS_CPU
+		- CONFIG_SYS_BOARD
+		- CONFIG_SYS_VENDOR
+		- CONFIG_SYS_SOC
+
 - DataFlash Support:
 		CONFIG_HAS_DATAFLASH
 
diff --git a/common/env_common.c b/common/env_common.c
index c33d22d..d9e990d 100644
--- a/common/env_common.c
+++ b/common/env_common.c
@@ -116,6 +116,17 @@
 #if defined(CONFIG_PCI_BOOTDELAY) && (CONFIG_PCI_BOOTDELAY > 0)
 	"pcidelay="	MK_STR(CONFIG_PCI_BOOTDELAY)	"\0"
 #endif
+#ifdef	CONFIG_ENV_VARS_UBOOT_CONFIG
+	"arch="		CONFIG_SYS_ARCH			"\0"
+	"cpu="		CONFIG_SYS_CPU			"\0"
+	"board="	CONFIG_SYS_BOARD		"\0"
+#ifdef CONFIG_SYS_VENDOR
+	"vendor="	CONFIG_SYS_VENDOR		"\0"
+#endif
+#ifdef CONFIG_SYS_SOC
+	"soc="		CONFIG_SYS_SOC			"\0"
+#endif
+#endif
 #ifdef	CONFIG_EXTRA_ENV_SETTINGS
 	CONFIG_EXTRA_ENV_SETTINGS
 #endif
diff --git a/common/env_embedded.c b/common/env_embedded.c
index 80fb29d..3872878 100644
--- a/common/env_embedded.c
+++ b/common/env_embedded.c
@@ -179,6 +179,17 @@
 #if defined(CONFIG_PCI_BOOTDELAY) && (CONFIG_PCI_BOOTDELAY > 0)
 	"pcidelay="	MK_STR(CONFIG_PCI_BOOTDELAY)	"\0"
 #endif
+#ifdef	CONFIG_ENV_VARS_UBOOT_CONFIG
+	"arch="		CONFIG_SYS_ARCH			"\0"
+	"cpu="		CONFIG_SYS_CPU			"\0"
+	"board="	CONFIG_SYS_BOARD		"\0"
+#ifdef CONFIG_SYS_VENDOR
+	"vendor="	CONFIG_SYS_VENDOR		"\0"
+#endif
+#ifdef CONFIG_SYS_SOC
+	"soc="		CONFIG_SYS_SOC			"\0"
+#endif
+#endif
 #ifdef	CONFIG_EXTRA_ENV_SETTINGS
 	CONFIG_EXTRA_ENV_SETTINGS
 #endif
diff --git a/mkconfig b/mkconfig
index daa1810..801f921 100755
--- a/mkconfig
+++ b/mkconfig
@@ -161,6 +161,14 @@
 	echo "#define CONFIG_${i}" >>config.h ;
 done
 
+echo "#define CONFIG_SYS_ARCH  \"${arch}\""  >> config.h
+echo "#define CONFIG_SYS_CPU   \"${cpu}\""   >> config.h
+echo "#define CONFIG_SYS_BOARD \"${board}\"" >> config.h
+
+[ "${vendor}" ] && echo "#define CONFIG_SYS_VENDOR \"${vendor}\"" >> config.h
+
+[ "${soc}"    ] && echo "#define CONFIG_SYS_SOC    \"${soc}\""    >> config.h
+
 cat << EOF >> config.h
 #define CONFIG_BOARDDIR board/$BOARDDIR
 #include <config_cmd_defaults.h>