u-boot启动加载rootfs失败，提示“VFS: Cannot open root device "(null)" or unknown-block(0,0): error -6”

pingfr

u-boot启动，加载zImage正常，加载到rootfs不正常，提示root参数不对，但对这教程看了几遍，“system-top.dts”文件里的“bootargs = "console=ttyPS0,115200 earlyprintk root=/dev/mmcblk0p2 rw rootwait"”也是对的，重新做了BOOT.BIN和rootfs，还是不行，看起来好像是启动参数没有传递过来，打印提示如下：
Xilinx Zynq CpuIdle Driver started
sdhci: Secure Digital Host Controller Interface driver
sdhci: Copyright(c) Pierre Ossman
sdhci-pltfm: SDHCI platform and OF driver helper
mmc0: SDHCI controller on e0100000.mmc [e0100000.mmc] using ADMA
mmc0: new high speed SDHC card at address 1234
mmcblk0: mmc0:1234 SA16G 14.4 GiB
mmcblk0: p1 p2
mmc1: SDHCI controller on e0101000.mmc [e0101000.mmc] using ADMA
ledtrig-cpu: registered to indicate activity on CPUs
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
fpga_manager fpga0: Xilinx Zynq FPGA Manager registered
NET: Registered protocol family 10
Segment Routing with IPv6
sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
NET: Registered protocol family 17
can: controller area network core (rev 20170425 abi 9)
NET: Registered protocol family 29
can: raw protocol (rev 20170425)
can: broadcast manager protocol (rev 20170425 t)
can: netlink gateway (rev 20170425) max_hops=1
Registering SWP/SWPB emulation handler
hctosys: unable to open rtc device (rtc0)
of_cfs_init
of_cfs_init: OK
ALSA device list:
  No soundcards found.
VFS: Cannot open root device "(null)" or unknown-block(0,0): error -6
Please append a correct "root=" boot option; here are the available partitions:
0100           16384 ram0
(driver?)
0101           16384 ram1
(driver?)

pingfr

初步摸索出一个解决办法，通过setenv增加bootargs变量并保存，重启后系统工作正常，还是不知道为啥u-boot的参数没有传递过来：
setenv bootargs "console=ttyPS0,115200 earlyprintk root=/dev/mmcblk0p2 rw rootwait"
saveenv
reset