IDK AM5718 HDMI 显示问题

镜像：am57xx-evm-linux-04.03.00.05.img.zip
sd卡启动，接HDMI时候报错：
root@am57xx-evm:~# [ 1045.203933] omapdss error: HDMI I2C Master Error
[ 1046.573997] omapdss error: HDMI I2C timeout reading EDID
# modetest 可以看到HDMI connected，但是报错omapdss error: HDMI I2C timeout reading EDID。
root@am57xx-evm:~# modetest
trying to open device 'i915'...failed
trying to open device 'radeon'...failed
trying to open device 'nouveau'...failed
trying to open device 'vmwgfx'...failed
trying to open device 'omapdrm'...done
[ 1741.246392] omapdss error: HDMI I2C timeout reading EDID
Encoders:
id crtc type possible crtcs possible clones
30 0 TMDS 0x00000001 0x00000000
Connectors:
id encoder status name size (mm) modes encoders
31 0 connected HDMI-A-1 0x0 6 30
modes:
name refresh (Hz) hdisp hss hse htot vdisp vss vse vtot)
1920x1080 60 1920 2040 2248 2576 1080 1081 1084 1118 flags: nhsync, pvsync; type: userdef
1024x768 60 1024 1048 1184 1344 768 771 777 806 flags: nhsync, nvsync; type: driver
800x600 60 800 840 968 1056 600 601 605 628 flags: phsync, pvsync; type: driver
800x600 56 800 824 896 1024 600 601 603 625 flags: phsync, pvsync; type: driver
848x480 60 848 864 976 1088 480 486 494 517 flags: phsync, pvsync; type: driver
640x480 60 640 656 752 800 480 490 492 525 flags: nhsync, nvsync; type: driver
props:
1 EDID:
flags: immutable blob
blobs:
value:
2 DPMS:
flags: enum
enums: On=0 Standby=1 Suspend=2 Off=3
value: 0

# kmscube 
root@am57xx-evm:~# kmscube
trying to load module omapdrm...success.
[ 2782.032332] omapdss error: HDMI I2C timeout reading EDID
### Display [0]: CRTC = 34, Connector = 31, format = 0x34325258
Mode chosen [1920x1080] : Clock => 172780, Vertical refresh => 60, Type => 32
Horizontal => 1920, 2040, 2248, 2576, 0
Vertical => 1080, 1081, 1084, 1118, 0
### Primary display => ConnectorId = 31, Resolution = 1920x1080
failed to load module: /usr/lib/gbm/gbm_dri.so: cannot open shared object file: No such file or directory
failed to load module: /usr/lib/gbm/gbm_gallium_drm.so: cannot open shared object file: No such file or directory
loaded module : gbm_pvr.so
found valid GBM backend : gbm_pvr.so
Using display 0x1 with EGL version 1.4
EGL Version "1.4 build 1.14@3699939 (MAIN)"
EGL Vendor "Imagination Technologies"
EGL Extensions "EGL_IMG_client_api_ogl EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_vg_parent_image EGL_IMG_cl_image EGL_KHR_fence_sync EGL_IMG_context_priority EGL_IMG_hibernate_process EGL_IMG_image_plane_attribs EGL_KHR_surfaceless_context EGL_KHR_wait_sync EGL_KHR_create_context EGL_WL_bind_wayland_display EGL_EXT_image_dma_buf_import"



请问要用HDMI显示的具体步骤是什么？