ipxe efi booting failed

[hohoajoma]

hi everyone..
i'm not speak English well.

i try ipxe booting with efi pc.
the boot in VMWare was a success, but real PC was failed.

i used ipxe.efi file : make bin-x86_64-efi/ipxe.efi DEBUG=efi_driver
when I used snponly.efi :make bin-x86-64/snponly.efi ,too.
why real pc ipxe booting is failed?
help me.

PC: Dell D7SVS02
NIC: rtl8168

message:
iPXE initialising devices..
EFIDRV connecting our drivers
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) has driver "PCI"
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) disconnecting existing drivers
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0) has driver "NII"
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0) DRIVER_START
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0) is not supported by driver "PCI": Error 0x7f10e183 (http://tpxe.org/7f10e183)
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0)/IPv4(0,0,0,0) has driver "SNP"
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0)/IPv4(0,0,0,0) DRIVER_START
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0)/IPv4(0,0,0,0) is not supported by driver "PCI": Error 0x7f10e183 (http://tpxe.org/7f10e183)
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0)/IPv4(0,0,0,0) is not supported by driver "NII": Error 0x7f10e183 (http://tpxe.org/7f10e183)
EFIDRV UNKNOEN<0xd0a0d398> could not start driver "SNP": Error 0x7f45e082 (http://tpxe.org/7f45e082)
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0)/IPv6(0000:0000:0000:0000:0000:0000:0000:0000) has driver "SNP"
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0)/IPv6(0000:0000:0000:0000:0000:0000:0000:0000) DRIVER_START
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0)/IPv6(0000:0000:0000:0000:0000:0000:0000:0000) is not supported by driver "PCI": Error 0x7f10e183 (http://tpxe.org/7f10e183)
EFIDRV PciRoot (0x0)/Pci (0x1c,0x4)/Pci(0x0,0x0) /MAC (c81f6625e234,0x0)/IPv6(0000:0000:0000:0000:0000:0000:0000:0000) is not supported by driver "NII": Error 0x7f10e183 (http://tpxe.org/7f10e183)
EFIDRV UNKNOEN<0xd0a0d398> could not start driver "SNP": Error 0x7f45e082 (http://tpxe.org/7f45e082)

And those message is repeated endless