HDMI support with Yocto and Freescale sabre

Question

I have a Freescale sabre, for which I have generate core-image-x11 with yocto. Booting and using it with serial port is ok, but I can't use the HDMI display. The HDMI is detected by u-boot, but not after. Here are some informations given by u-boot :

U-Boot 2014.10+fslc+g5fd0b60 (Feb 27 2015 - 11:26:20)

CPU:   Freescale i.MX6Q rev1.2 at 792 MHz
Reset cause: POR
Board: MX6-SabreSD
I2C:   ready
DRAM:  1 GiB
MMC:   FSL_SDHC: 0, FSL_SDHC: 1, FSL_SDHC: 2
auto-detected panel HDMI
Display: HDMI (1024x768)
In:    serial
Out:   serial
Err:   serial
PMIC:  PFUZE100 ID=0x10
Net:   FEC [PRIME]

I have tried this in u-boot :

setenv mmcargs 'setenv bootargs console=ttymxc0,115200 root=/dev/mmcblk0p2 rootwait rw video=mxcfb0'

But it doesn't change anything, even if the modification can be seen in /proc/cmdline after the booting ; and

setenv mmcargs 'setenv bootargs console=ttymxc0,115200 root=/dev/mmcblk0p2 rootwait rw video=mxcfb0:dev=hdmi'

makes the booting stopping at starting kernel .

Answer 1

You may need to add a complete video specification:

video=mxcfb0:dev=hdmi,1024x768M@60,bpp=32

The mxcfb driver can be picky about its parameters. If it still doesn't work, you'll probably have to convince the driver to tell you more about what's going wrong to get more useful advice.