Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
device tree
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Gentoo on ARM
View previous topic :: View next topic  
Author Message
Gentoopc
n00b
n00b


Joined: 25 Dec 2017
Posts: 36

PostPosted: Sat May 26, 2018 10:30 am    Post subject: device tree Reply with quote

hello, tell me how to bind a device tree to a new compiled kernel? Is it possible to somehow transfer the kernel to an old dtb or need to compile from dts?
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 41087
Location: 56N 3W

PostPosted: Sat May 26, 2018 11:21 am    Post subject: Reply with quote

Gentoopc,

On what system?

e.g. on Raspberry Pi, the dtb is loaded with the kernel and the kernel picks it up as a part of of the initialisation process.
the dtb is its own file so you can mix and match kernel and dtb files. You might not like the results but its very easy.

If you need a dtb, the kernel build process will build it.

Its also possible to merge the dtb into the kernel. Exactly how is system dependent.
There will be a software tool for this.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.
Back to top
View user's profile Send private message
Gentoopc
n00b
n00b


Joined: 25 Dec 2017
Posts: 36

PostPosted: Sat May 26, 2018 6:20 pm    Post subject: Reply with quote

ls /boot before installing the kernel
Code:

armbianEnv.txt
armbian_first_run.txt.template
bat
boot.bmp
boot.cmd
boot-desktop.png
boot.scr
config-3.10.107-pine64
dtb
dtb-3.10.107-pine64
dtb-3.10.107-pine64.old
Image
Image-3.10.107-pine64
initrd.img
initrd.img-3.10.107-pine64
System.map-3.10.107-pine64
t.txt
uInitrd
uInitrd-3.10.107-pine64




after installing the kernel
Code:

armbianEnv.txt
armbian_first_run.txt.template
bat
boot.bmp
boot.cmd
boot-desktop.png
boot.scr
config-3.10.107-pine64
config-4.14.43kernelmy
dtb
dtb-3.10.107-pine64
dtb-3.10.107-pine64.old
Image
Image-3.10.107-pine64
initrd.img
initrd.img-3.10.107-pine64
initrd.img-4.14.43kernelmy
System.map-3.10.107-pine64
System.map-4.14.43kernelmy
t2.txt
uInitrd
uInitrd-3.10.107-pine64
uInitrd-4.14.43kernelmy
vmlinuz-4.14.43kernelmy

vmlinuz-4.14.43kernelmy-
this is the kernel that I built and on it you can see the link


but what can I do with dtb now?


what should I do next?[/topic][/url][/profile][/bug]
Back to top
View user's profile Send private message
Gentoopc
n00b
n00b


Joined: 25 Dec 2017
Posts: 36

PostPosted: Sat May 26, 2018 6:24 pm    Post subject: Reply with quote

orange pi win+
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 41087
Location: 56N 3W

PostPosted: Sat May 26, 2018 8:12 pm    Post subject: Reply with quote

Gentoopc,

The kernel build will have made you a dtb too.
It will be in /usr/src/linux/arch/arm64/boot/dts/... for arm64 or in /usr/src/linux/arch/arm/boot/dts/... for 32 bit.

Mainline kernel support will be patchy to not existent.
There is a reason the vendor kernel is Image-3.10.107-pine64 ... that's based on 3.10.107.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.
Back to top
View user's profile Send private message
szatox
Veteran
Veteran


Joined: 27 Aug 2013
Posts: 1682

PostPosted: Sat May 26, 2018 11:19 pm    Post subject: Reply with quote

Raspberrypi-sources comes with default configs and dtbs for a whole lot of different boards.
It did work out of the box for my banana (well, figuring things out took me a while, but it wasn't dtb's fault), if you find a config for your board there, you have a good chance to get it up and running without any modifications. Running defconfig for your boad will set things up for you. You can tweak some modules later, after you have something that at least boots.
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 41087
Location: 56N 3W

PostPosted: Sun May 27, 2018 7:56 am    Post subject: Reply with quote

Moved from Gentoo Chat to Gentoo on ARM.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.
Back to top
View user's profile Send private message
Gentoopc
n00b
n00b


Joined: 25 Dec 2017
Posts: 36

PostPosted: Sun May 27, 2018 11:00 am    Post subject: Reply with quote

Many thanks to you, dear
Back to top
View user's profile Send private message
erm67
Apprentice
Apprentice


Joined: 01 Nov 2005
Posts: 215
Location: Where the black men cannot enter

PostPosted: Thu May 31, 2018 6:41 am    Post subject: Reply with quote

The dts binds HW resources to symbolic names that are referenced by drivers in the kernel, sometimes, for obscure reasons ( :lol: ) the names are changed by developers, or new symbolic names are added. Of course the change must happen on both sides, in the dtb and the kernel driver. That is why it is always wise to use the dtb specific to a kernel version, if possible of course.
Nice intro to device trees:
slides
https://events.static.linuxfound.org/sites/events/files/slides/petazzoni-device-tree-dummies.pdf
video
https://www.youtube.com/watch?v=m_NyYEBxfn8

The drivers in kernel x.y.z expecs to find the symbolic names as defined in the dts that was shipped with it, using a different version might or might not work.

For example using the dtb from kernel 4.4.14 with kernel 4.4.16 on my amlogic S912 board resulted into a non working USB ...... problem solved with the correct dtb (I am also too lazy to update the dtb all the times).
_________________
True ignorance is not the absence of knowledge, but the refusal to acquire it.
A posse ad esse non valet consequentia
Πάντα ῥεῖ
Back to top
View user's profile Send private message
Gentoopc
n00b
n00b


Joined: 25 Dec 2017
Posts: 36

PostPosted: Thu May 31, 2018 11:23 am    Post subject: Reply with quote

erm67 wrote:
The dts binds HW resources to symbolic names that are referenced by drivers in the kernel, sometimes, for obscure reasons ( :lol: ) the names are changed by developers, or new symbolic names are added. Of course the change must happen on both sides, in the dtb and the kernel driver. That is why it is always wise to use the dtb specific to a kernel version, if possible of course.
Nice intro to device trees:
slides
https://events.static.linuxfound.org/sites/events/files/slides/petazzoni-device-tree-dummies.pdf
video
https://www.youtube.com/watch?v=m_NyYEBxfn8

The drivers in kernel x.y.z expecs to find the symbolic names as defined in the dts that was shipped with it, using a different version might or might not work.

For example using the dtb from kernel 4.4.14 with kernel 4.4.16 on my amlogic S912 board resulted into a non working USB ...... problem solved with the correct dtb (I am also too lazy to update the dtb all the times).




I do not have dtb in the / arch / arm64 / dts folder

I tried to compile myself but nothing happened
Back to top
View user's profile Send private message
NeddySeagoon
Administrator
Administrator


Joined: 05 Jul 2003
Posts: 41087
Location: 56N 3W

PostPosted: Thu May 31, 2018 6:46 pm    Post subject: Reply with quote

Gentoopc,

I do not have dtb in the / arch / arm64 / dts folder.

That's correct.
Code:
 /usr/src/linux/arch/arm64/boot/dts $ ls
actions  allwinner  amd      apm  broadcom  exynos     hisilicon  Makefile  mediatek  qcom     renesas   socionext  xilinx
al       altera     amlogic  arm  cavium    freescale  lg         marvell   nvidia    realtek  rockchip  sprd       zte

The dts older is further divided into CPU vendors.

You have an allwinner CPU.
Code:
$ ls allwinner/
axp803.dtsi                  sun50i-a64-olinuxino.dts         sun50i-a64-sopine.dtsi          sun50i-h5-orangepi-pc2.dts         sun50i-h6-pine-h64.dts
Makefile                     sun50i-a64-orangepi-win.dts      sun50i-a64-teres-i.dts          sun50i-h5-orangepi-prime.dts
sun50i-a64-bananapi-m64.dts  sun50i-a64-pine64.dts            sun50i-h5.dtsi                  sun50i-h5-orangepi-zero-plus2.dts
sun50i-a64.dtsi              sun50i-a64-pine64-plus.dts       sun50i-h5-nanopi-neo2.dts       sun50i-h5-orangepi-zero-plus.dts
sun50i-a64-nanopi-a64.dts    sun50i-a64-sopine-baseboard.dts  sun50i-h5-nanopi-neo-plus2.dts  sun50i-h6.dtsi

The kernel build system should have left several dtb files there.
Pick the one for you CPU.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Gentoo on ARM All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum