Print U-boot, kernel info to the screen

cancel
Showing results for 
Search instead for 
Did you mean: 

Print U-boot, kernel info to the screen

6,498 Views
erikraynolds
Contributor III

Dears,

I've installed https://community.nxp.com/docs/DOC-330147  on imx6qp and want to have a print on my HDMI screen during booting. I'm able to have print output on host PC onto console output. Is it possible to configure it such a way that to have 'print' of booting onto attached screen. for now I have have login GUI .

Thanks.

11 Replies

2,337 Views
fabio_estevam
NXP Employee
NXP Employee

Hi Erik,

We do use HDMI output by default on a mx6cubox board if it detects that HDMI cable is connected.

You can get the details at git.denx.de Git - u-boot.git/blob - include/configs/mx6cuboxi.h 

but the relevant logic is:

"if hdmidet; then " \
"usb start; " \
"setenv stdin serial,usbkbd; "\
"setenv stdout serial,vga; " \
"setenv stderr serial,vga; " \
"else " \
"setenv stdin serial; " \
"setenv stdout serial; " \
"setenv stderr serial; " \
"fi;"

Regards,

Fabio Estevam

2,337 Views
erikraynolds
Contributor III

Is it possible to modify it within u-boot console?

> setenv stdin serial,usbkbd
> setenv stdout serial,vga
> setenv stderr serial,vga
> saveenv

but I when setenv stdout vga then uboot console freeze. Have you ever try it to set from console?

0 Kudos

2,337 Views
fabio_estevam
NXP Employee
NXP Employee

I don't see the hang here when I run "setenv stdout vga".

Make sure HDMI support is enabled in U-Boot.

0 Kudos

2,337 Views
erikraynolds
Contributor III

What you mean by enabling U-boot support?

I do:

setenv mmcargs $mmcargs video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24
saveenv

then

> setenv stdin serial,usbkbd
> setenv stdout serial,vga
> setenv stderr serial,vga
> saveen

Do you mean another way to make sure HDMI support is enabled?

0 Kudos

2,337 Views
fabio_estevam
NXP Employee
NXP Employee

I am asking if you have enabled HDMI support inside U-Boot, ie, U-Boot is capable of outputting a splash screen via HDMI.

0 Kudos

2,337 Views
fabio_estevam
NXP Employee
NXP Employee

Or maybe I misunderstood your goal: it seems you want to get the kernel log printed into HDMI.

If this is the case you need to pass: console=tty0 prior to console=ttymxc0,115200 into your kernel command line.

0 Kudos

2,337 Views
erikraynolds
Contributor III

for u-boot

$ wget –c http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/snapshot/uboot-imx-rel_imx_4.1.15_2.0.0_ga.t...  
$ tar -xf uboot-imx-rel_imx_4.1.15_2.0.0_ga.tar.gz  
$ cd uboot-imx-rel_imx_4.1.15_2.0.0_ga  
$ make $mx6qpsabreauto_config 
$ make

no other than this config I did.

I'd like to have u-boot from within HDMI console (setenv stdout vga just hangs)

# Enabling HDMI comsole
setenv panel HDMI
setenv stdout serial,vga
setenv stderr serial,vga
saveenv

# To tell U-Boot to accept console input from a USB keyboard, run the following commands:
setenv stdin serial,usbkbd
saveenv

# To make U-Boot detect the USB keyboard on boot, run the following commands:
setenv preboot "usb start"
saveenv

as you asked: I am asking if you have enabled HDMI support inside U-Boot,

I think that's what I'm missing...

How can I enable HDMI support inside U-Boot?

0 Kudos

2,337 Views
fabio_estevam
NXP Employee
NXP Employee

NXP U-Boot disables HDMI support.

You can reference mx6cuboxi board that enables HDMI support in U-Boot for reference.

0 Kudos

2,337 Views
RossMcLuckie
NXP Employee
NXP Employee

Have you tried to download the associated documentation package -

Embedded Linux for i.MX Applications Processors|NXP 

From memory the default output is LVDS, but the QSG or similar documentation explains how to switch to the HDMI output.

Regards

Ross

0 Kudos

2,338 Views
erikraynolds
Contributor III

Yes, I did. I got the documentation package for fsl-yocto-L4.1.15_2.0.0-ga. Can please point me where can I find more about?

BTW I switch the output to HDMI

setenv mmcargs 'setenv bootargs console=ttymxc0,115200 root=/dev/mmcblk2p2 rootwait rw video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24'

Actually I've got output of GUI but no booting info which I can onky see on host console of PC via UART (console=ttymxc3)

0 Kudos

2,338 Views
RossMcLuckie
NXP Employee
NXP Employee

I found this How to config the hdmi with uboot

Hopefully this helps, I also tried a quick google for outputting Linux console messages on HDMI, threw up a lot of hits, so might be worth a look there also, if above doesn't help.

Ross