仅仅尝试一下编译，暂时不知道用来干啥
cd <kernel root path>
进入内核源代码根目录
make tools/help
查看tools的帮助信息
Possible targets:
acpi - ACPI tools
cgroup - cgroup tools
cpupower - a tool for all things x86 CPU power
firewire - the userspace part of nosy, an IEEE-1394 traffic sniffer
freefall - laptop accelerometer program for disk protection
gpio - GPIO tools
hv - tools used when in Hyper-V clients
iio - IIO tools
kvm_stat - top-like utility for displaying kvm statistics
leds - LEDs tools
liblockdep - user-space wrapper for kernel locking-validator
bpf - misc BPF tools
perf - Linux performance measurement and analysis tool
selftests - various kernel selftests
spi - spi tools
objtool - an ELF object analysis tool
tmon - thermal monitoring and tuning tool
turbostat - Intel CPU idle stats and freq reporting tool
usb - USB testing tools
virtio - vhost test module
vm - misc vm tools
wmi - WMI interface examples
x86_energy_perf_policy - Intel energy policy tool
You can do:
$ make -C tools/ <tool>_install
from the kernel command line to build and install one of
the tools above
$ make tools/all
builds all tools.
$ make tools/install
installs all tools.
Cleaning targets:
all of the above with the "_clean" string appended cleans
the respective build directory.
clean: a summary clean target to clean _all_ folders
使用如下命令进行单独编译某一部分工具：
- make tools/usb
- make tools/iio
- make tools/gpio
- make tools/perf