Support to boot armbian from SDCard

Author: hzyitc

board/amlogic/configs/m8b_onecloud.h

@@ -169,7 +169,7 @@
 // =============================================================================
 #define CONFIG_PREBOOT				"run prepare_video; run check_usbburn; print 'Waiting for autoboot...'"
 #define CONFIG_BOOTDELAY			3
-#define CONFIG_BOOTCOMMAND			"print 'Autobooting...'; run boot_usb_armbian; run boot_emmc_armbian; print 'Failed to boot'; "
+#define CONFIG_BOOTCOMMAND			"print 'Autobooting...'; run boot_usb_armbian; run boot_sdcard_armbian; run boot_emmc_armbian; print 'Failed to boot'; "
 #define CONFIG_HOSTNAME				"onecloud"
 #define CONFIG_ETHADDR				00:15:18:01:81:31
 #define CONFIG_IPADDR				192.168.1.150
@@ -224,10 +224,18 @@
 	"loadaddr=0x12000000\0" \
 	"boot_emmc_armbian=" \
 		"print -n 'Try to boot from eMMC...'; " \
+		"mmc rescan 1; " \
 		"setenv bootdev 'mmc 1'; " \
 		"fatload ${bootdev} ${loadaddr} boot.scr && autoscr ${loadaddr}; " \
 		"print 'Fail'; " \
 		"\0" \
+	"boot_sdcard_armbian=" \
+		"print -n 'Try to boot from SDCard...'; " \
+		"mmc rescan 0; " \
+		"setenv bootdev 'mmc 0'; " \
+		"fatload ${bootdev} ${loadaddr} boot.scr && autoscr ${loadaddr}; " \
+		"print 'Fail'; " \
+		"\0" \
 	"boot_usb_armbian=" \
 		"print -n 'Try to boot from USB...'; " \
 		"setenv bootdev 'usb 0'; " \