I add my modification on your dragonboard-dev branch. But it failed to boot from USB hard drive.
I tried to connect my USBtoSerial board and voltage level shifter board (convert between 3.3v and 1.8v) to pin 5 and pin 7 on dragonboard UART0. But I saw nothing in my PC. Could you recommend how to debug u-boot?
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diff --git a/include/configs/dragonboard.h b/include/configs/dragonboard.h
index 30cfc84…4c7c60f 100644
— a/include/configs/dragonboard.h
+++ b/include/configs/dragonboard.h
@@ -83,6 +83,9 @@
#define CONFIG_USB_ETHER_MCS7830
#define CONFIG_USB_ETHER_SMSC95XX
+/File System/
+#define CONFIG_CMD_EXT4 /* EXT4 support /
+
/ Libraries */
#define CONFIG_MD5
@@ -127,7 +130,7 @@
#define CONFIG_BOOTP_BOOTFILESIZE
/* Environment - Boot*/
-#define CONFIG_BOOTDELAY -1 /* autoboot after 5 seconds /
+#define CONFIG_BOOTDELAY 5 / autoboot after 5 seconds */
#define CONFIG_SERVERIP 10.0.0.1
#define CONFIG_IPADDR 10.0.0.2
@@ -135,8 +138,8 @@
#define CONFIG_NFSBOOTCOMMAND “”
#define CONFIG_ROOTPATH “/home/nfs/dragonboard”
#define CONFIG_BOOTFILE “dragonboard/linux.itb”
-#define CONFIG_BOOTCOMMAND “usb start && tftp && usb stop && bootm”
-#define CONFIG_BOOTARGS “console=ttyMSM0,115200n8”
+#define CONFIG_BOOTCOMMAND “usb start; usb storage; ext4load usb 0:1 0x90000000 /boot/uImage; ext4load usb 0:1 0x89000000 /boot/apq8016-sbc.dtb; bootm 0x90000000 – 0x89000000”
+#define CONFIG_BOOTARGS “root=UUID=ae5fa761-95be-469b-b7dc-a355d080ed23 rw rootwait console=tty0 console=ttyMSM0,115200n8 rootfs=ext4 noinitrd selinux=0”
/* Does what recovery does */
#define REFLASH(file, part) \