TMS570LC4357: Ethernet Bootloader startup Getting PHY ID !!! ERROR !!!

Tool/software:

HI Team:

      I am using the Ethernet Bootloader on TMS570LC43x Hercules Development Kit (HDK). Now I can already burn Build-TMS570LC43x-tftpBoot.out through xds100v2. At present, when using the debug mode of CCS (9.1), the serial port prints the following information:

Ethernet lwIP Bootloader
DEBUG - Getting PHY ID....SUCCESS
DEBUG - Getting PHY Alive Status...SUCCESS
DEBUG - Getting PHY Link Status...SUCCESS
DEBUG - Setting up Link...SUCCESS
HDK IP Address: 192.168.86.121

     When I power on and restart, the serial port prints the following information:

DEBUG - Getting PHY ID...............................................................................................................................................................................................................................................................................................!!! ERROR !!!
DEBUG - Getting PHY Alive Status...!!! ERROR !!!HDK IP Address: 0.0.0.0
Ethernet lwIP Bootloader

1. Why is the startup through CCS debug different from normal power-on startup?
2. How should we solve the problem that the PHY ID cannot be read during normal power-on startup?

Thank you sincerely for your reply.