Uboot使用tftp卡住了

按照手册F2.5 Uboot 使用 TFTP，尝试通过tftp启动,卡在了Waiting for root device /dev/mmcblk0p2...，如下：
。。。。。。
[    1.980408] Registering the dns_resolver key type
[    1.985441] VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev 3
[    1.993461] ThumbEE CPU extension supported.
[    1.997981] mux: Failed to setup hwmod io irq -22
[    2.003558] Power Management for AM33XX family
[    2.008428] Trying to load am335x-pm-firmware.bin (60 secs timeout)
[    2.015121] Copied the M3 firmware to UMEM
[    2.019473] Cortex M3 Firmware Version = 0x181
[    2.029181] clock: disabling unused clocks to save power
[    2.036887] Detected MACID=64:33:db:16:21:96
[    2.042822] cpsw: Detected MACID = 64:33:db:16:21:98
[    2.049652] input: gpio-keys as /devices/platform/gpio-keys/input/input1
[    2.058412] rtc-rx8010 1-0032: setting system clock to 2022-06-10 07:11:50 UTC (1654845110)
[    2.067717] Waiting for root device /dev/mmcblk0p2...


然后就走不下去了。请高手指点。

参考下附件中的方法https://bbs.forlinx.com/forum.php?mod=attachment&aid=MTMyODl8NDI1ZDcyOWR8MTc5MTY1OTc5MnwwfA%3D%3D