07-12-2018, 10:07 PM
(This post was last modified: 07-12-2018, 10:40 PM by ab1jx.
Edit Reason: fbcon note
)
This is maybe the most promising thing I've found: https://linux-sunxi.org/Display The default video mode can be fed to uboot in a string like
A bunch of that looks like what's in /boot/cmdline.txt on a Raspberry Pi. Uboot passes it to the kernel. I haven't found anything like it on my Rock64. But in there you can set the video mode, like 1280x720 above. I know nothing about uboot except what it does, it boots mostly ARM machines and it's open source. The Raspberry Pi doesn't use it, it uses a bootloader from Broadcom so an open source alternative was needed. There must be a way to pass a command line to the kernel on a Rock64.
My latest search was https://duckduckgo.com/?q=uboot+hdmi+mode&t=h_&ia=web There's more stuff than I can absorb quickly.
Just guessing, fbcon here is the console one, fb0 (aka card0?) is the one X uses? There's only /dev/fb0 though.
The X framebuffer and console one seem to be the same size on the screen, but the console one seems to stay at 1920x1080 while I can change the X one with lxrandr. It seems stable at 1024x768. I've rebooted a few times and it's in the same mode. OK, so /sys is kernel output stuff: https://superuser.com/questions/794198/d...s-in-linux
Code:
# fixed mode
setenv bootargs console=tty0 hdmi.audio=EDID:0 disp.screen0_output_mode=1280x720p60 root=/dev/mmcblk0p1 rootwait panic=10A bunch of that looks like what's in /boot/cmdline.txt on a Raspberry Pi. Uboot passes it to the kernel. I haven't found anything like it on my Rock64. But in there you can set the video mode, like 1280x720 above. I know nothing about uboot except what it does, it boots mostly ARM machines and it's open source. The Raspberry Pi doesn't use it, it uses a bootloader from Broadcom so an open source alternative was needed. There must be a way to pass a command line to the kernel on a Rock64.
My latest search was https://duckduckgo.com/?q=uboot+hdmi+mode&t=h_&ia=web There's more stuff than I can absorb quickly.
Just guessing, fbcon here is the console one, fb0 (aka card0?) is the one X uses? There's only /dev/fb0 though.
Code:
rock64# pwd
/sys/class/graphics
rock64# ls -la
total 0
drwxr-xr-x 2 root root 0 Jul 13 04:20 .
drwxr-xr-x 64 root root 0 Jul 13 04:20 ..
lrwxrwxrwx 1 root root 0 Jul 13 04:20 fb0 -> ../../devices/platform/display-subsystem/graphics/fb0
lrwxrwxrwx 1 root root 0 Jul 13 04:20 fbcon -> ../../devices/virtual/graphics/fbcon
rock64# The X framebuffer and console one seem to be the same size on the screen, but the console one seems to stay at 1920x1080 while I can change the X one with lxrandr. It seems stable at 1024x768. I've rebooted a few times and it's in the same mode. OK, so /sys is kernel output stuff: https://superuser.com/questions/794198/d...s-in-linux
