一、概述
Linux
内核编译流程如下:
1、配置 Linux
内核。
2、编译 Linux
内核。
说明:进入 Linux
内核源码,使用 make help
参看相关配置。
二、make menuconfig 工作原理
1、menuconfig
它本身是一个软件,只提供图形界面配置的一些逻辑,并不负责提供内容。
2、menuconfig
是内核源码树的各目录下的 kconfig
提供的。
3、menuconfig
中所有选中配置项的相关值会保存到配置文件中(默认配置文件为 .config
)。
4、在编译内核时,Makefile
根据相关配置项选择需要编译的源码。
三、Kconfig 语法
参考文档:Documentation/kbuild/kconfig-language.txt
。
Linux 驱动开发 六十五:《kconfig-language.txt》翻译_lqonlylove的博客-CSDN博客
四、Linux 内核中 Kconfig 分析
1、顶层 Kconfig 内容
## For a description of the syntax of this configuration file,# see Documentation/kbuild/kconfig-language.txt.#mainmenu "Linux/$ARCH $KERNELVERSION Kernel Configuration"config SRCARCHstringoption env="SRCARCH"source "arch/$SRCARCH/Kconfig"
mainmenu
:标题栏;config
:定义配置项;string
:数据类型;env
:导入Kconfig
的环境变量;
source
:读取的配置文件位置。
2、arch/arm/Kconfig 内容
……source "init/Kconfig" # 包含配置文件source "kernel/Kconfig.freezer"menu "System Type" # 定义配置菜单栏config MMU# 在 System Type 下定义配置项bool "MMU-based Paged Memory Management Support"default yhelp Select if you want MMU-based virtualised addressing space support by paged memory management. If unsure, say 'Y'.## The "ARM system type" choice list is ordered alphabetically by option# text. Please add new entries in the option alphabetic order.#choiceprompt "ARM system type"default ARCH_VERSATILE if !MMUdefault ARCH_MULTIPLATFORM if MMUconfig ARCH_MULTIPLATFORMbool "Allow multiple platforms to be selected"depends on MMUselect ARCH_WANT_OPTIONAL_GPIOLIBselect ARM_HAS_SG_CHAINselect ARM_PATCH_PHYS_VIRTselect AUTO_ZRELADDRselect CLKSRC_OFselect COMMON_CLKselect GENERIC_CLOCKEVENTSselect MIGHT_HAVE_PCIselect MULTI_IRQ_HANDLERselect SPARSE_IRQselect USE_OF……config ARCH_VERSATILEbool "ARM Ltd. Versatile family"select ARCH_WANT_OPTIONAL_GPIOLIBselect ARM_AMBAselect ARM_TIMER_SP804select ARM_VICselect CLKDEV_LOOKUPselect GENERIC_CLOCKEVENTSselect HAVE_MACH_CLKDEVselect ICSTselect PLAT_VERSATILEselect PLAT_VERSATILE_CLOCKselect PLAT_VERSATILE_SCHED_CLOCKselect VERSATILE_FPGA_IRQhelp This enables support for ARM Ltd Versatile board. ……menu "Multiple platform selection"depends on ARCH_MULTIPLATFORM# Multiple platform selection 依赖 ARCH_MULTIPLATFORM 配置项comment "CPU Core family selection"……## This is sorted alphabetically by mach-* pathname. However, plat-*# Kconfigs may be included either alphabetically (according to the# plat- suffix) or along side the corresponding mach-* source.#source "arch/arm/mach-mvebu/Kconfig"……menu "Bus support"……menu "Kernel Features"menu "CPU Power Management"source "drivers/cpufreq/Kconfig"source "drivers/cpuidle/Kconfig"endmenumenu "Floating point emulation"comment "At least one emulation must be selected"endmenu……menu "Userspace binary formats"source "fs/Kconfig.binfmt"endmenumenu "Power management options"source "kernel/power/Kconfig"endmenusource "net/Kconfig"source "drivers/Kconfig"source "drivers/firmware/Kconfig"source "fs/Kconfig"source "arch/arm/Kconfig.debug"source "security/Kconfig"source "crypto/Kconfig"if CRYPTOsource "arch/arm/crypto/Kconfig"endifsource "lib/Kconfig"source "arch/arm/kvm/Kconfig"
source
:包含一个配置文件;menu
:定义一个菜单项;choice
:定义一个选项组;config
:定义一个配置项;comment
:定义一个注释;
3、其他配置文件
五、测试
1、添加菜单
为了方便测试,在顶层 Kconfig
下添加一个 bool
配置项,配置项内容如下:
menu "onlylove test"endmenu
2、添加 bool 类型配置
menu "onlylove test"config ONLYLOVE_TESTbool "onlylove test Management Support"endmenu
3、添加 tristate 类型配置
menu "onlylove test"config ONLYLOVE_TESTtristate "onlylove test Management Support"endmenu
4、添加 string 类型配置
menu "onlylove test"config ONLYLOVE_TESTstring "onlylove test Management Support"endmenu
5、添加 hex 类型配置
menu "onlylove test"config ONLYLOVE_TESThex "onlylove test Management Support"endmenu
6、添加 int 类型值
menu "onlylove test"config ONLYLOVE_TESTint "onlylove test Management Support"endmenu
7、查看配置是否生效
1、添加菜单和配置项
menu "onlylove test"config ONLYLOVE_TESTtristate "onlylove test Management Support"endmenu
2、查看旧配置文件
onlylove@ubuntu:~/my/linux/linux-imx-4.1.15$ cat .config | grep ONLYLOVE_TEST# CONFIG_ONLYLOVE_TEST is not setonlylove@ubuntu:~/my/linux/linux-imx-4.1.15$
3、选中 onlylove test Management Support
配置项
4、查看新配置文件
onlylove@ubuntu:~/my/linux/linux-imx-4.1.15$ cat .config | grep ONLYLOVE_TESTCONFIG_ONLYLOVE_TEST=monlylove@ubuntu:~/my/linux/linux-imx-4.1.15$
六、向 Linux 内核中添加自己编写驱动
1、确定驱动所属类型
ICM-20608
属于SPI
设备。
2、找到对应Kconfig文件
onlylove@ubuntu:~/my/linux/linux-imx-4.1.15/drivers/spi$ pwd/home/onlylove/my/linux/linux-imx-4.1.15/drivers/spionlylove@ubuntu:~/my/linux/linux-imx-4.1.15/drivers/spi$ ls -l Kconfig -rw-rw-r-- 1 onlylove onlylove 20563 May 24 2019 Kconfigonlylove@ubuntu:~/my/linux/linux-imx-4.1.15/drivers/spi$
3、添加驱动文件
onlylove@ubuntu:~/my/linux/linux-imx-4.1.15/drivers/spi$ pwd/home/onlylove/my/linux/linux-imx-4.1.15/drivers/spionlylove@ubuntu:~/my/linux/linux-imx-4.1.15/drivers/spi$ ls -l spi-icm2068.cls: cannot access 'spi-icm2068.c': No such file or directoryonlylove@ubuntu:~/my/linux/linux-imx-4.1.15/drivers/spi$ cp -f ~/my/imx6ull_drive/13_icm20608_spi/spi-icm2068.c ./onlylove@ubuntu:~/my/linux/linux-imx-4.1.15/drivers/spi$ ls -l spi-icm2068.c-rw-rw-r-- 1 onlylove onlylove 12758 Nov 13 00:25 spi-icm2068.conlylove@ubuntu:~/my/linux/linux-imx-4.1.15/drivers/spi$
4、添加配置项
config ONLYLOVE_ICM20608 tristate "Icm20608 Device Support" help This supports user icm20608 device.
onlylove@ubuntu:~/my/linux/linux-imx-4.1.15$ cat .config | grep ONLYLOVE_ICM20608CONFIG_ONLYLOVE_ICM20608=yonlylove@ubuntu:~/my/linux/linux-imx-4.1.15$
5、添加Makefile编译项
obj-$(CONFIG_ONLYLOVE_ICM20608) += spi-icm2068.o
6、编译内核
onlylove@ubuntu:~/my/linux/linux-imx-4.1.15$ make -j4scripts/kconfig/conf --silentoldconfig Kconfig CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.hmake[1]: 'include/generated/mach-types.h' is up to date. CHK include/generated/bounds.h CHK include/generated/asm-offsets.h CALL scripts/checksyscalls.sh CHK include/generated/compile.h CC drivers/spi/spi-icm2068.o LD drivers/spi/built-in.o LD drivers/built-in.o LINK vmlinux LD vmlinux.o MODPOST vmlinux.o GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o LD init/built-in.o KSYM .tmp_kallsyms1.o KSYM .tmp_kallsyms2.o LD vmlinux SORTEX vmlinux SYSMAP System.map OBJCOPY arch/arm/boot/Image Building modules, stage 2. MODPOST 27 modules Kernel: arch/arm/boot/Image is ready LZO arch/arm/boot/compressed/piggy.lzo AS arch/arm/boot/compressed/piggy.lzo.o LD arch/arm/boot/compressed/vmlinux OBJCOPY arch/arm/boot/zImage Kernel: arch/arm/boot/zImage is readyonlylove@ubuntu:~/my/linux/linux-imx-4.1.15$
日志 CC drivers/spi/spi-icm2068.o
表示 spi-icm2068
驱动编译成功。
7、驱动测试
1、Linux 启动日志
以上日志可以确定 icm20608
驱动加载成功。icm20608
设备 ID
读取成功。
2、app程序调用icm20608驱动
# lsicm20608_app# ls -l /dev/icm20608crw-rw---- 1 root root 10, 62 Jan 1 00:00 /dev/icm20608## ./icm20608_app /dev/icm20608data[0] = 6 data[1] = 13 data[2] = 0 data[3] = 43 data[4] = 6 data[5] = 2067原始值:gx = 6, gy = 13, gz = 0ax = 43, ay = 6, az = 2067temp = 1715实际值:act gx = 0.37°/S, act gy = 0.79°/S, act gz = 0.00°/Sact ax = 0.02g, act ay = 0.00g, act az = 1.01gact temp = 30.17°Cdata[0] = 7 data[1] = 13 data[2] = 0 data[3] = 39 data[4] = 8 data[5] = 2063原始值:gx = 7, gy = 13, gz = 0ax = 39, ay = 8, az = 2063temp = 1708实际值:act gx = 0.43°/S, act gy = 0.79°/S, act gz = 0.00°/Sact ax = 0.02g, act ay = 0.00g, act az = 1.01gact temp = 30.15°Cdata[0] = 8 data[1] = 12 data[2] = -1 data[3] = 43 data[4] = 11 data[5] = 2067原始值:gx = 8, gy = 12, gz = -1ax = 43, ay = 11, az = 2067temp = 1711实际值:act gx = 0.49°/S, act gy = 0.73°/S, act gz = -0.06°/Sact ax = 0.02g, act ay = 0.01g, act az = 1.01gact temp = 30.16°C^C#
数据读取成功。