按照mmwave-studio-cascade-user guide文件里操作，第五步booting the evm里，串口软件一直重复下列报错信息：
U-Boot SPL 2016.05-00018-g6bc25a5 (Aug 05 2019 - 14:43:03)
DRA752-GP ES2.0
no pinctrl for hs200_1_8v
no pinctrl for ddr_1_8v
Card did not respond to voltage select!
*** Warning - MMC init failed, using default environment
Trying to boot from MMC1
reading dra7-ipu2-fw.lzop
spl_load_file_fat: error reading file dra7-ipu2-fw.lzop, err - -1
spl: error reading image dra7-ipu2-fw.lzop, err - -1
Error loading remotecore IPU2!,Continuing with boot ...
reading dra7-dsp1-fw.lzop
spl_load_file_fat: error reading file dra7-dsp1-fw.lzop, err - -1
spl: error reading image dra7-dsp1-fw.lzop, err - -1
Error loading remotecore DSP1!,Continuing with boot ...
reading dra7-dsp2-fw.lzop
spl_load_file_fat: error reading file dra7-dsp2-fw.lzop, err - -1
spl: error reading image dra7-dsp2-fw.lzop, err - -1
Error loading remotecore DSP2!,Continuing with boot ...
reading dra7-ipu1-fw.lzop
spl_load_file_fat: error reading file dra7-ipu1-fw.lzop, err - -1
spl: error reading image dra7-ipu1-fw.lzop, err - -1
Error loading remotecore IPU1!,Continuing with boot ...
spl: falcon_args_file not set in environment, falling back to default
reading single-stage-boot.dtb
spl_load_image_fat_os: error reading image single-stage-boot.dtb, err - -1
reading u-boot.img
reading u-boot.img
reading u-boot.img
reading u-boot.img
