Hello.
I've installed FreeBSD 14.2-RELEASE on both my boards (RockPro64 and Khadas Edge V),both based on the Rockchip RK3399 and I've used a display that has a resolution of 720 x 720 resolution and I saw that the screen remains almost black (almost because I see a dim illumination coming from the display) .
I don't even see the u-boot logo. Instead,it is able to turn on my large HDMI monitor,which has a resolution of 1920x1080 pixels.
Since I'm building a FreeBSD modular phone, I want to use a small HDMI display with a low resolution. My question is : why is u-boot able to turn on a monitor that has a resolution of 1920x1080 and it's not able to turn on the other HDMI display that has a resolution of 720x720 ?
Or even better : what's the lowest resolution that will work ?
If I want to buy a display that has a resolution of 800x600,will u-boot be able to turn it on ? 1024x768 ? more ?
Thanks.
On 19.08.25 17:54, Mario Marietto wrote:
Hello.
I've installed FreeBSD 14.2-RELEASE on both my boards (RockPro64 and Khadas Edge V),both based on the Rockchip RK3399 and I've used a display that has a resolution of 720 x 720 resolution and I saw that the screen remains almost black (almost because I see a dim illumination coming from the display) .
I don't even see the u-boot logo. Instead,it is able to turn on my large HDMI monitor,which has a resolution of 1920x1080 pixels.
Since I'm building a FreeBSD modular phone, I want to use a small HDMI display with a low resolution. My question is : why is u-boot able to turn on a monitor that has a resolution of 1920x1080 and it's not able to turn on the other HDMI display that has a resolution of 720x720 ?
Or even better : what's the lowest resolution that will work ?
If I want to buy a display that has a resolution of 800x600,will u-boot be able to turn it on ? 1024x768 ? more ?
Thanks.
Hello Mario,
The way operating systems detect monitor resolution is by reading the EDID information via the I2C lines of the HDMI connector.
U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information. This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid will provide the people and the U-Boot list that you could contact for support.
There is also a #u-boot IRC channel at irc.libera.chat.
Best regards
Heinrich
---> U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information.
This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid
Hello. Since u-boot should be installed on FreeBSD,can you point me where I can get the khadas-edge-v-rk3399_defconfig file and the u-boot code that should be recompiled ?
On Tue, Aug 19, 2025 at 6:23 PM Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 19.08.25 17:54, Mario Marietto wrote:
Hello.
I've installed FreeBSD 14.2-RELEASE on both my boards (RockPro64 and
Khadas
Edge V),both based on the Rockchip RK3399 and I've used a display that
has
a resolution of 720 x 720 resolution and I saw that the screen remains almost black (almost because I see a dim illumination coming from the display) .
I don't even see the u-boot logo. Instead,it is able to turn on my large HDMI monitor,which has a resolution of 1920x1080 pixels.
Since I'm building a FreeBSD modular phone, I want to use a small HDMI display with a low resolution. My question is : why is u-boot able to
turn
on a monitor that has a resolution of 1920x1080 and it's not able to turn on the other HDMI display that has a resolution of 720x720 ?
Or even better : what's the lowest resolution that will work ?
If I want to buy a display that has a resolution of 800x600,will u-boot
be
able to turn it on ? 1024x768 ? more ?
Thanks.
Hello Mario,
The way operating systems detect monitor resolution is by reading the EDID information via the I2C lines of the HDMI connector.
U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information. This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid will provide the people and the U-Boot list that you could contact for support.
There is also a #u-boot IRC channel at irc.libera.chat.
Best regards
Heinrich
On 20.08.25 12:40, Mario Marietto wrote:
---> U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information.
This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid
Hello. Since u-boot should be installed on FreeBSD,can you point me where I can get the khadas-edge-v-rk3399_defconfig file and the u-boot code that should be recompiled ?
The U-Boot project is hosted at https://source.denx.de/u-boot/u-boot.
FreeBSD's U-Boot port is described at https://www.freshports.org/sysutils/u-boot-master.
Best regards
Heinrich
On Tue, Aug 19, 2025 at 6:23 PM Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 19.08.25 17:54, Mario Marietto wrote:
Hello.
I've installed FreeBSD 14.2-RELEASE on both my boards (RockPro64 and
Khadas
Edge V),both based on the Rockchip RK3399 and I've used a display that
has
a resolution of 720 x 720 resolution and I saw that the screen remains almost black (almost because I see a dim illumination coming from the display) .
I don't even see the u-boot logo. Instead,it is able to turn on my large HDMI monitor,which has a resolution of 1920x1080 pixels.
Since I'm building a FreeBSD modular phone, I want to use a small HDMI display with a low resolution. My question is : why is u-boot able to
turn
on a monitor that has a resolution of 1920x1080 and it's not able to turn on the other HDMI display that has a resolution of 720x720 ?
Or even better : what's the lowest resolution that will work ?
If I want to buy a display that has a resolution of 800x600,will u-boot
be
able to turn it on ? 1024x768 ? more ?
Thanks.
Hello Mario,
The way operating systems detect monitor resolution is by reading the EDID information via the I2C lines of the HDMI connector.
U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information. This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid will provide the people and the U-Boot list that you could contact for support.
There is also a #u-boot IRC channel at irc.libera.chat.
Best regards
Heinrich
->The way operating systems detect monitor resolution is by reading the ->EDID information via the I2C lines of the HDMI connector.
->U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information. ->This is not enabled by khadas-edge-v-rk3399_defconfig.
Excuse Me for the "rude" question,but are you sure of what you say ? Because if that was the case,u-boot didn't work even on my large HDMI monitor with a resolution of 1920x1080. But it works there. Using the pure logic reasoning I assume that it is able to parse EDID information.
I'm also sure that it works with a monitor that has a lower resolution than 1920x1080,maybe 1600x1440. Point here is that I think there is a resolution limit under which it will stop working. How can I know what this is ?
The easier method is to buy a new display,let's say that runs at 1024x768 and check,but...it costs money. I would like to know what this limit is asking here and there.
On Wed, Aug 20, 2025 at 12:55 PM Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 20.08.25 12:40, Mario Marietto wrote:
---> U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information.
This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid
Hello. Since u-boot should be installed on FreeBSD,can you point me
where I
can get the khadas-edge-v-rk3399_defconfig file and the u-boot code that should be recompiled ?
The U-Boot project is hosted at https://source.denx.de/u-boot/u-boot.
FreeBSD's U-Boot port is described at https://www.freshports.org/sysutils/u-boot-master.
Best regards
Heinrich
On Tue, Aug 19, 2025 at 6:23 PM Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 19.08.25 17:54, Mario Marietto wrote:
Hello.
I've installed FreeBSD 14.2-RELEASE on both my boards (RockPro64 and
Khadas
Edge V),both based on the Rockchip RK3399 and I've used a display that
has
a resolution of 720 x 720 resolution and I saw that the screen remains almost black (almost because I see a dim illumination coming from the display) .
I don't even see the u-boot logo. Instead,it is able to turn on my
large
HDMI monitor,which has a resolution of 1920x1080 pixels.
Since I'm building a FreeBSD modular phone, I want to use a small HDMI display with a low resolution. My question is : why is u-boot able to
turn
on a monitor that has a resolution of 1920x1080 and it's not able to
turn
on the other HDMI display that has a resolution of 720x720 ?
Or even better : what's the lowest resolution that will work ?
If I want to buy a display that has a resolution of 800x600,will u-boot
be
able to turn it on ? 1024x768 ? more ?
Thanks.
Hello Mario,
The way operating systems detect monitor resolution is by reading the EDID information via the I2C lines of the HDMI connector.
U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information. This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid will provide the people and the U-Boot list that you could contact for support.
There is also a #u-boot IRC channel at irc.libera.chat.
Best regards
Heinrich
->The way operating systems detect monitor resolution is by reading the ->EDID information via the I2C lines of the HDMI connector.
->U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information. ->This is not enabled by khadas-edge-v-rk3399_defconfig.
Here it is. I'm here to show you the proof that your suggestion had something that did not convince me. I've just remembered that I had two displays,stored inside the shelf,that could be tested,to see if they work with u-boot and the khadas-edge-v. The first one is a 4 inch display,720x720 from waveshare,the second one is a 480x480 from a Chinese brand. The result that I've got is the same for both :
https://drive.google.com/file/d/1InM4f4DLcYX8Y3ntERItnhwVuEnmHWeK/view?usp=s...
What happens is that u-boot is able to show the first stage of messages on the screen and then it becomes black and it remains black....
On Wed, Aug 20, 2025 at 1:54 PM Mario Marietto marietto2008@gmail.com wrote:
->The way operating systems detect monitor resolution is by reading the ->EDID information via the I2C lines of the HDMI connector.
->U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information. ->This is not enabled by khadas-edge-v-rk3399_defconfig.
Excuse Me for the "rude" question,but are you sure of what you say ? Because if that was the case,u-boot didn't work even on my large HDMI monitor with a resolution of 1920x1080. But it works there. Using the pure logic reasoning I assume that it is able to parse EDID information.
I'm also sure that it works with a monitor that has a lower resolution than 1920x1080,maybe 1600x1440. Point here is that I think there is a resolution limit under which it will stop working. How can I know what this is ?
The easier method is to buy a new display,let's say that runs at 1024x768 and check,but...it costs money. I would like to know what this limit is asking here and there.
On Wed, Aug 20, 2025 at 12:55 PM Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 20.08.25 12:40, Mario Marietto wrote:
---> U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information.
This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid
Hello. Since u-boot should be installed on FreeBSD,can you point me
where I
can get the khadas-edge-v-rk3399_defconfig file and the u-boot code that should be recompiled ?
The U-Boot project is hosted at https://source.denx.de/u-boot/u-boot.
FreeBSD's U-Boot port is described at https://www.freshports.org/sysutils/u-boot-master.
Best regards
Heinrich
On Tue, Aug 19, 2025 at 6:23 PM Heinrich Schuchardt <xypron.glpk@gmx.de
wrote:
On 19.08.25 17:54, Mario Marietto wrote:
Hello.
I've installed FreeBSD 14.2-RELEASE on both my boards (RockPro64 and
Khadas
Edge V),both based on the Rockchip RK3399 and I've used a display that
has
a resolution of 720 x 720 resolution and I saw that the screen remains almost black (almost because I see a dim illumination coming from the display) .
I don't even see the u-boot logo. Instead,it is able to turn on my
large
HDMI monitor,which has a resolution of 1920x1080 pixels.
Since I'm building a FreeBSD modular phone, I want to use a small HDMI display with a low resolution. My question is : why is u-boot able to
turn
on a monitor that has a resolution of 1920x1080 and it's not able to
turn
on the other HDMI display that has a resolution of 720x720 ?
Or even better : what's the lowest resolution that will work ?
If I want to buy a display that has a resolution of 800x600,will
u-boot
be
able to turn it on ? 1024x768 ? more ?
Thanks.
Hello Mario,
The way operating systems detect monitor resolution is by reading the EDID information via the I2C lines of the HDMI connector.
U-Boot has CONFIG_I2C_EDID to build a module to parse EDID information. This is not enabled by khadas-edge-v-rk3399_defconfig. I would assume this is part of the problem.
scripts/get_maintainer.pl configs/khadas-edge-v-rk3399_defconfig and scripts/get_maintainer.pl common/edid will provide the people and the U-Boot list that you could contact for support.
There is also a #u-boot IRC channel at irc.libera.chat.
Best regards
Heinrich
-- Mario.
boot-architecture@lists.linaro.org
-
Heinrich Schuchardt -
Mario Marietto