SS928:无法挂载分区

我烧录完ss928dev-emmc.zip的固件包后，
如上图所示，我可以看到我的 /dev/mmcblk0 大小为15G，其中 mmcblk0p3 挂载到了根节点，大小为120M，
但我无法15G中出去120M之外的其他空间，
并且fdisk指令会报错：
Disk /dev/mmcblk0p1 doesn’t contain a valid partition table
请问该如何解决？

我看网上别人也有遇到此类问题，但未解决：
https://blog.csdn.net/luohaha66/article/details/138085194

~ # fdisk -l
Disk /dev/mmcblk0: 15 GB, 15634268160 bytes, 30535680 sectors
477120 cylinders, 4 heads, 16 sectors/track
Units: sectors of 1 * 512 = 512 bytes

Disk /dev/mmcblk0 doesn't contain a valid partition table
Disk /dev/mmcblk0p1: 1 MB, 1048576 bytes, 2048 sectors
32 cylinders, 4 heads, 16 sectors/track
Units: sectors of 1 * 512 = 512 bytes

Disk /dev/mmcblk0p1 doesn't contain a valid partition table
~ # mount
/dev/root on / type ext4 (rw,relatime)
devtmpfs on /dev type devtmpfs (rw,relatime,size=232500k,nr_inodes=58125,mode=755)
proc on /proc type proc (rw,nosuid,nodev,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,relatime)
devpts on /dev/pts type devpts (rw,relatime,mode=600,ptmxmode=000)
tmpfs on /run type tmpfs (rw,relatime)
~ # ls -l /dev/root
lrwxrwxrwx    1 root     root             9 Jan  1 00:00 /dev/root -> mmcblk0p3
~ # ls /dev/mmcblk0*
/dev/mmcblk0       /dev/mmcblk0boot1  /dev/mmcblk0p2     /dev/mmcblk0rpmb
/dev/mmcblk0boot0  /dev/mmcblk0p1     /dev/mmcblk0p3
~ # ls
~ # mkdir p2
~ # mount /dev/mmcblk0p2 p2/
mount: mounting /dev/mmcblk0p2 on p2/ failed: Invalid argument
~ # mkdir p1
~ # mount /dev/mmcblk0p1 p1/
mount: mounting /dev/mmcblk0p1 on p1/ failed: Invalid argument
~ # df -h
Filesystem                Size      Used Available Use% Mounted on
/dev/root               120.0M     92.4M     18.6M  83% /
devtmpfs                227.1M         0    227.1M   0% /dev
tmpfs                   229.2M         0    229.2M   0% /run
~ #