21 openwrt kernel module changed to.Ko automatic loading

openwrt There are many open source kernel modules located in package/kernel/ Next , Such as gpio-button-hotplug、mwlwifi etc. . These modules are after the file system starts , adopt autoload By insmod Loaded .

1、 Normal thinking

stay 《Openwrt add function module to package》 There are introductions in the chapter , How to add a kernel module .

The above introduction is to add a kernel Application module , And compile it into .ko Automatically loaded . If it is the module code already in the kernel , How to change it into .ko Automatically load .

There was a problem during debugging , The kernel phy Sent hotplug Premature event , This event has been issued before the file system is started , This applies to /etc/hotplug.d/phy/ The following script cannot be executed to , Cause state judgment problems .

Normal thinking ,make kernel_menuconfig take phy The configuration of is changed to m

-CONFIG_MT753X_GSW=y
+CONFIG_MT753X_GSW=m

After this modification , The module confirmation of the discovery kernel is compiled into mt753x.ko 了 , But no one will change ko Copy to the file system , In this way, there is no way to automatically load .

2、 Revise the plan

Found behind openwrt This integration method already exists , be located package/kernel/linux/modules/ Next .

stay 19.07/package/kernel/linux/modules/netdevices.mk Inside , Add the following information .

With adding a kernel package similar , Appoint ko The path of FILES, Then set the AUTOLOAD Start sequence value of .

 define KernelPackage/switch-mt753x
   SUBMENU:=$(NETWORK_DEVICES_MENU)
   TITLE:=MediaTek MT753x switch support
   DEPENDS:=+kmod-switch-mt753x
   KCONFIG:=CONFIG_MT753X_GSW
   FILES:=$(LINUX_DIR)/drivers/net/phy/mtk/mt753x/mt753x.ko
   AUTOLOAD:=$(call AutoLoad,43,mt753x)
 endef
 
 define KernelPackage/switch-mt753x/description
  MediaTek MT753x switch support
 endef
 
 $(eval $(call KernelPackage,switch-mt753x))
 

After adding configuration options ,make menuconfig take switch-mt753x Module check , take make kernel_menuconfig Inside MT753X_GSW=n Uncheck it .