参考链接：
https://blog.csdn.net/psvoldemort/article/details/7258205
USB存储涉及两个方面：
1、usb子系统需要配置usb存储驱动
2、U盘格式化的文件系统类型包含在内核支持的文件系统类型中
RK3399 Linux系统默认支持FAT32、ext2、ext4等文件系统类型，现在想要添加对ntfs格式U盘的支持。
usb存储驱动
kernel/drivers/usb/storage
Device Drivers ---> [*] USB support ---><*> USB Mass Storage support
文件系统类型配置
内核中添加ntfs配置
make menuconfigFile systems ---><*> The Extended 4 (ext4) filesystemDOS/FAT/NT Filesystems ---><*> NTFS file system support[ ] NTFS debugging support[*] NTFS write support
其他支持的文件系统类型
File systems ---><*> The Extended 4 (ext4) filesystemDOS/FAT/NT Filesystems --->文件系统挂载
在内核里添加了ntfs的支持配置以后，/dev/sda1以ntfs格式挂载到了/media/sda1
默认挂载信息如下：
[root@rk3399:/]# cat /etc/mtab
/dev/root / ext4 rw,relatime,data=ordered 0 0
devtmpfs /dev devtmpfs rw,relatime,size=1836696k,nr_inodes=459174,mode=755 0 0
proc /proc proc rw,relatime 0 0
devpts /dev/pts devpts rw,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /dev/shm tmpfs rw,relatime,mode=777 0 0
tmpfs /tmp tmpfs rw,relatime 0 0
tmpfs /run tmpfs rw,nosuid,nodev,relatime,mode=755 0 0
sysfs /sys sysfs rw,relatime 0 0
debug /sys/kernel/debug debugfs rw,relatime 0 0
pstore /sys/fs/pstore pstore rw,relatime 0 0
/dev/mmcblk2p7 /media/mmcblk2p7 ext2 rw,relatime 0 0
/dev/mmcblk2p8 /media/mmcblk2p8 ext4 rw,relatime,data=ordered 0 0
/dev/mmcblk2p9 /media/mmcblk2p9 ext2 rw,relatime 0 0
/dev/mmcblk2p7 /oem ext2 rw,relatime 0 0
/dev/mmcblk2p9 /userdata ext2 rw,relatime 0 0
/dev/sda1 /media/sda1 ntfs ro,relatime,uid=0,gid=0,fmask=0177,dmask=077,nls=utf8,errors=continue,mft_zone_multiplier=1 0 0
none /sys/kernel/config configfs rw,relatime 0 0
adb /dev/usb-ffs/adb functionfs rw,relatime 0 0
/dev/mmcblk2p9 /usr/bin/bt_pcba_test ext2 rw,relatime 0 0
可以看到/dev/sda1被挂载为了ro权限，系统加载信息如下：
[ 82.461477] FAT-fs (sda1): utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive!
[ 82.589623] ntfs: volume version 3.1.
[ 82.589962] ntfs: (device sda1): load_system_files(): Volume is dirty. Mounting read-only. Run chkdsk and mount in Windows.
报的信息让检查修复U盘，但是U盘是刚格式化好的，问题应该不是出在这（个人看法，如果有正确的方法，希望可以私信我）
添加mount.ntfs等工具
为了解决上一步遇到的权限问题，查看了一下buildroot中的配置选项，使能了BR2_PACKAGE_NTFS_3G编译选项
diff --git a/buildroot/configs/rockchip_rk3399_defconfig b/buildroot/configs/rockchip_rk3399_defconfig
index 5efae234f..5bd30fb73 100644
--- a/buildroot/configs/rockchip_rk3399_defconfig
+++ b/buildroot/configs/rockchip_rk3399_defconfig
@@ -1072,7 +1072,7 @@ BR2_PACKAGE_EXFAT_UTILS=y# BR2_PACKAGE_MTOOLS is not set# BR2_PACKAGE_NFS_UTILS is not set# BR2_PACKAGE_NILFS_UTILS is not set
-# BR2_PACKAGE_NTFS_3G is not set
+BR2_PACKAGE_NTFS_3G=y# BR2_PACKAGE_SP_OOPS_EXTRACT is not set# BR2_PACKAGE_SQUASHFS is not set# BR2_PACKAGE_SSHFS is not set
编译后添加了如下三个工具
mount.ntfs
mount.lowntfs-3g
mount.ntfs-3g映射关系如下：
[root@rk3399:/]# ls /sbin/mount.* -al
lrwxrwxrwx 1 root root 16 May 15 2021 /sbin/mount.exfat -> mount.exfat-fuse
-rwxr-xr-x 1 root root 39544 Jul 9 2021 /sbin/mount.exfat-fuse
lrwxrwxrwx 1 root root 19 Jul 9 2021 /sbin/mount.lowntfs-3g -> /usr/bin/lowntfs-3g
lrwxrwxrwx 1 root root 13 Jul 9 2021 /sbin/mount.ntfs -> mount.ntfs-3g
lrwxrwxrwx 1 root root 16 Jul 9 2021 /sbin/mount.ntfs-3g -> /usr/bin/ntfs-3g
对应的库文件为
[root@rk3399:/]# ls -al /usr/lib/libntfs-3g.so.88*
lrwxrwxrwx 1 root root 20 Jul 9 2021 /usr/lib/libntfs-3g.so.88 -> libntfs-3g.so.88.0.0
-rwxr-xr-x 1 root root 238304 Jul 9 2021 /usr/lib/libntfs-3g.so.88.0.0
卸载掉默认的挂载路径之后，使用mount.ntfs重新挂载U盘设备，写权限就有了
[root@rk3399:/]# ls /media/ -al
total 50
drwxr-xr-x 14 root root 4096 Jan 1 00:00 .
drwxr-xr-x 26 root root 4096 Jan 1 00:01 ..
drwxr-xr-x 3 root root 1024 Jul 9 2021 mmcblk2p7
drwxr-xr-x 26 root root 4096 Jan 1 00:01 mmcblk2p8
drwxr-xr-x 6 root root 1024 Jan 1 00:00 mmcblk2p9
dr-x------ 1 root root 4096 Jan 1 00:00 sda1
drwxr-xr-x 2 root root 4096 May 15 2021 usb0
drwxr-xr-x 2 root root 4096 May 15 2021 usb1
drwxr-xr-x 2 root root 4096 May 15 2021 usb2
drwxr-xr-x 2 root root 4096 May 15 2021 usb3
drwxr-xr-x 2 root root 4096 May 15 2021 usb4
drwxr-xr-x 2 root root 4096 May 15 2021 usb5
drwxr-xr-x 2 root root 4096 May 15 2021 usb6
drwxr-xr-x 2 root root 4096 May 15 2021 usb7[root@rk3399:/]# umount /media/sda1
[root@rk3399:/]# mount.ntfs /dev/sda1 /media/sda1[root@rk3399:/]# ls /media/ -al
total 50
drwxr-xr-x 14 root root 4096 Jan 1 00:00 .
drwxr-xr-x 26 root root 4096 Jan 1 00:01 ..
drwxr-xr-x 3 root root 1024 Jul 9 2021 mmcblk2p7
drwxr-xr-x 26 root root 4096 Jan 1 00:01 mmcblk2p8
drwxr-xr-x 6 root root 1024 Jan 1 00:00 mmcblk2p9
drwxrwxrwx 1 root root 4096 Jan 1 00:00 sda1
drwxr-xr-x 2 root root 4096 May 15 2021 usb0
drwxr-xr-x 2 root root 4096 May 15 2021 usb1
drwxr-xr-x 2 root root 4096 May 15 2021 usb2
drwxr-xr-x 2 root root 4096 May 15 2021 usb3
drwxr-xr-x 2 root root 4096 May 15 2021 usb4
drwxr-xr-x 2 root root 4096 May 15 2021 usb5
drwxr-xr-x 2 root root 4096 May 15 2021 usb6
drwxr-xr-x 2 root root 4096 May 15 2021 usb7
[root@rk3399:/]# cp /home/forlinx/audio/test.mp3 /media/sda1/
[root@rk3399:/]# sync
[root@rk3399:/]# ls /media/sda1/
'System Volume Information' test.mp3
ntfs U盘自动挂载读写
TBC
（PS：下载中提供了ntfs-3g工具和库文件）