mx7: set soc environment according to exact SoC type

This can be useful if the same U-Boot binary is used for boards
available with a i.MX 7Solo and i.MX 7Dual.

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/arm/cpu/armv7/mx7/soc.c

@@ -248,6 +248,20 @@ int arch_cpu_init(void)
 	return 0;
 }
 
+#ifdef CONFIG_ARCH_MISC_INIT
+int arch_misc_init(void)
+{
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
+	if (is_mx7d())
+		setenv("soc", "imx7d");
+	else
+		setenv("soc", "imx7s");
+#endif
+
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_SERIAL_TAG
 void get_board_serial(struct tag_serialnr *serialnr)
 {

include/configs/mx7_common.h

@@ -28,6 +28,8 @@
 /* Enable iomux-lpsr support */
 #define CONFIG_IOMUX_LPSR
 
+#define CONFIG_ARCH_MISC_INIT
+
 #define CONFIG_DISPLAY_CPUINFO
 #define CONFIG_DISPLAY_BOARDINFO