这个我不太清楚。设备树编译操作：
我直接通过反编译方式修改设备树。
操作：1.cp /boot/kernel_tegra234-p3767-0004-p3768-0000-a0-user-custom.dtb ~/tegra234-p3767-0004-p3768-0000-a0.dtb
2.dtc -I dtb -O dts tegra234-p3767-0004-p3768-0000-a0.dtb > aaaa.dts
3.修改aaaa.dts
4.反编译设备树：
dtc -I dts -O dtb -o aaaa.dtb aaaa.dts
5.sudo cp aaaa.dts /boot/kernel_tegra234-p3767-0004-p3768-0000-a0-user-custom.dtb
我的extlinux.conf设置：
ys@tegra-ubuntu:~$ cat /boot/extlinux/extlinux.conf
TIMEOUT 30
DEFAULT JetsonIO
MENU TITLE L4T boot options
LABEL primary
MENU LABEL primary kernel
LINUX /boot/Image
FDT /boot/dtb/kernel_tegra234-p3767-0004-p3768-0000-a0.dtb
INITRD /boot/initrd
APPEND quiet pcie_aspm=off quiet pcie_aspm=off quiet pcie_aspm=off ${cbootargs} root=PARTUUID=2f87cd33-5c3e-4aef-836f-b9b8f761175b rw rootwait rootfstype=ext4 mminit_loglevel=4 console=ttyTCU0,115200 console=ttyAMA0,115200 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0 tegra_firewall=0
When testing a custom kernel, it is recommended that you create a backup of
the original kernel and add a new entry to this file so that the device can
fallback to the original kernel. To do this:
1, Make a backup of the original kernel
sudo cp /boot/Image /boot/Image.backup
2, Copy your custom kernel into /boot/Image
3, Uncomment below menu setting lines for the original kernel
4, Reboot
LABEL backup
MENU LABEL backup kernel
LINUX /boot/Image.backup
FDT /boot/dtb/kernel_tegra234-p3767-0004-p3768-0000-a0.dtb
INITRD /boot/initrd
APPEND quiet pcie_aspm=off quiet pcie_aspm=off quiet pcie_aspm=off ${cbootargs}
LABEL JetsonIO
MENU LABEL Custom Header Config: <HDR40 User Custom [2025-10-29-020911]>
LINUX /boot/Image
FDT /boot/kernel_tegra234-p3767-0004-p3768-0000-a0-user-custom.dtb
INITRD /boot/initrd
APPEND quiet pcie_aspm=off quiet pcie_aspm=off quiet pcie_aspm=off ${cbootargs} root=PARTUUID=2f87cd33-5c3e-4aef-836f-b9b8f761175b rw rootwait rootfstype=ext4 mminit_loglevel=4 console=ttyTCU0,115200 console=ttyAMA0,115200 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0 tegra_firewall=0
ys@tegra-ubuntu:~$
您好！请问有时间能帮我看看？这是哪里 操作有问题？
Okay, your operation would only take effect for kernel DTB.
Please refer to DTB Support for the workflow of DTB loading.
DTB will be built into UEFI binary during flash(i.e. uefi_jetson_with_dtb).
As a result, please update the DTB under <Linux_for_Tegra>/kernel/dtb/tegra234-p3767-0004-p3768-0000-a0.dtb instead before flash.
非常非常感谢您的帮助。
目前按照您说的方式操作了。我提供下列操作步骤。
操作步骤：
1.进入~/nvidia/35.3/Linux_for_Tegra/source/public/hardware/nvidia/platform/t23x/p3768/kernel-dts/cvb
2.修改
ys@ubuntu:~/nvidia/35.3/Linux_for_Tegra/source/public/hardware/nvidia/platform/t23x/p3768/kernel-dts/cvb (master)$ cat tegra234-p3768-0000-a0-pwm-fan.dtsi
/ {
pwm-fan {
compatible = "pwm-fan";
status = "okay";
pwms = <&tegra_pwm5 0 45334>;
#cooling-cells = <2>;
cooling-levels = <128 135 178 200 255 255 255 255 255 255>;
};
};
3.配置编译环境：
export DEVDIR=/home/ys/nvidia/35.3/Linux_for_Tegra
export CROSS_COMPILE_AARCH64_PATH=/home/ys/nvidia/35.3/l4t-gcc
export CROSS_COMPILE_AARCH64=/home/ys/nvidia/35.3/l4t-gcc/bin/aarch64-buildroot-linux-gnu-
export ARCH=arm64
export CROSS_COMPILE=$CROSS_COMPILE_AARCH64
export KERNEL_HEADERS=$DEVDIR/source/public/kernel_out
export INSTALL_MOD_PATH=$DEVDIR/rootfs
export TEGRA_KERNEL_OUT=/home/ys/nvidia/35.3/Linux_for_Tegra/source/public/kernel_out
export LOCALVERSION="-tegra"
cd /home/ys/nvidia/35.3/Linux_for_Tegra/source/public/kernel/kernel-5.10
4.编译
make ARCH=arm64 O=$TEGRA_KERNEL_OUT dtbs
5.进入
~/nvidia/35.3/Linux_for_Tegra/source/public/kernel_out/arch/arm64/boot/dts/nvidia
6.反编译设备树查看配置情况
dtc -I dtb -O dts tegra234-p3767-0004-p3768-0000-a0.dtb > aaaa.dts
7.将tegra234-p3767-0004-p3768-0000-a0.dtb文件拷贝到
/home/ys/nvidia/35.3/Linux_for_Tegra/kernel/dtb
8.将tegra234-p3767-0004-p3768-0000-a0.dtb替换orin nano套件开发板
/boot/kernel_tegra234-p3767-0004-p3768-0000-a0-user-custom.dtb
9.使用刷机指令：
sudo ./flash.sh -k A_cpu-bootloader -c bootloader/t186ref/cfg/flash_t234_qspi.xml jetson-orin-nano-devkit nvme0n1p1
疑问：1.为什么我修改tegra234-p3768-0000-a0-pwm-fan.dtsi ，改成了tegra_pwm5，为什么我反编译查看pwms = <0x2c3 0x00 0xb116>, 0x2c3与默认配置的pwm3 是一样的。
2.UEFI阶段和进入系统后风扇都在运行。
ys@tegra-ubuntu:~$ cat /etc/nv_tegra_release
# R35 (release), REVISION: 3.1, GCID: 32827747, BOARD: t186ref, EABI: aarch64, DATE: Sun Mar 19 15:19:21 UTC 2023
ys@tegra-ubuntu:~$
ys@tegra-ubuntu:~$ cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.5 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.5 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal
ys@tegra-ubuntu:~$ cat /boot/extlinux/extlinux.conf
TIMEOUT 30
DEFAULT JetsonIO
MENU TITLE L4T boot options
LABEL primary
MENU LABEL primary kernel
LINUX /boot/Image
FDT /boot/dtb/kernel_tegra234-p3767-0004-p3768-0000-a0.dtb
INITRD /boot/initrd
APPEND quiet pcie_aspm=off quiet pcie_aspm=off quiet pcie_aspm=off ${cbootargs} root=PARTUUID=2f87cd33-5c3e-4aef-836f-b9b8f761175b rw rootwait rootfstype=ext4 mminit_loglevel=4 console=ttyTCU0,115200 console=ttyAMA0,115200 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0 tegra_firewall=0
# When testing a custom kernel, it is recommended that you create a backup of
# the original kernel and add a new entry to this file so that the device can
# fallback to the original kernel. To do this:
#
# 1, Make a backup of the original kernel
# sudo cp /boot/Image /boot/Image.backup
#
# 2, Copy your custom kernel into /boot/Image
#
# 3, Uncomment below menu setting lines for the original kernel
#
# 4, Reboot
# LABEL backup
# MENU LABEL backup kernel
# LINUX /boot/Image.backup
# FDT /boot/dtb/kernel_tegra234-p3767-0004-p3768-0000-a0.dtb
# INITRD /boot/initrd
# APPEND quiet pcie_aspm=off quiet pcie_aspm=off quiet pcie_aspm=off ${cbootargs}
LABEL JetsonIO
MENU LABEL Custom Header Config: <HDR40 User Custom [2025-10-29-020911]>
LINUX /boot/Image
FDT /boot/kernel_tegra234-p3767-0004-p3768-0000-a0-user-custom.dtb
INITRD /boot/initrd
APPEND quiet pcie_aspm=off quiet pcie_aspm=off quiet pcie_aspm=off ${cbootargs} root=PARTUUID=2f87cd33-5c3e-4aef-836f-b9b8f761175b rw rootwait rootfstype=ext4 mminit_loglevel=4 console=ttyTCU0,115200 console=ttyAMA0,115200 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0 tegra_firewall=0
ys@tegra-ubuntu:~$
Do you confirm that tegra234-p3768-0000-a0-pwm-fan.dtsi has been included in your case?
025-10-30 17:37:22] ~~~~DeviceDiscoveryNotify: Unable to locate address range for Tegra PWM
From the log your shared, it seems TegraPwmDxe.c can not recognize the pwm3.
Please run the following command on your board and provide extracted_proc.dts again.
$ sudo dtc -I fs -O dts -o extracted_proc.dts /proc/device-tree
感谢您的回复！
请在帮我看看。
extracted_proc.dts.txt (414.1 KB)
From the device tree you shared, it seems the pwm-fan has been configured to get PWM signal from pwm5.
tegra_pwm5 = "/pwm@32c0000";
pwm@32c0000 {
clock-names = "pwm\0parent\0slow-parent";
resets = <0x02 0x48>;
clocks = <0x02 0x6d 0x02 0x66 0x02 0x0e>;
nvidia,hw-instance-id = <0x04>;
#pwm-cells = <0x02>;
compatible = "nvidia,tegra194-pwm";
status = "okay";
reg = <0x00 0x32c0000 0x00 0x10000>;
phandle = <0x2c3>;
reset-names = "pwm";
};
pwm-fan {
cooling-levels = <0x80 0x87 0xb2 0xc8 0xff 0xff 0xff 0xff 0xff 0xff>;
compatible = "pwm-fan";
status = "okay";
pwms = <0x2c3 0x00 0xb116>;
#cooling-cells = <0x02>;
};
Do you mean the fan is still working now?
It should not work as it is not connected from pwm5 from HW..
Could you also get a scope to check where’s the PWM input coming for FAN now?
Please check the pinmux configuration first.
