3 ways to compile the driver into the kernel (using mini2440 key as an example)

3 ways to compile the driver into the kernel-----(Take mini2440 key as an example)

Method 1: Compile and add to the kernel as a module (the simplest method)

Note: key.c (key_hui.c) is the driver code, Makefile is the compilation rule, key.ko is the driver. key_irq is the test code.

(1). In the source program directory, make arch=arm, and the key.ko file will be generated.

(2) After the system boots and enters the console, insmod key.ko

(3) View the device number cat /proc/devices

(4) Create a node: mknod /dev/globalmem c 235 0 (some kernels support automatic node creation while others do not)

Or: in the startup script of the file system, for example, add a line at the end of etc/profile: source /testshell, and then add the following loading command in the testshell in the root directory, the driver will be automatically loaded after the system starts, such as:

#!/bin/sh

ehco "i am testshell"

insmod /minitest/key.ko ----Mount the driver

mknod /dev/key_driver c 253 0 -----Create node

exec /minitest/key_irq -----Execute the application

(5) Uninstall the device: rmmod key.ko

Method 2: Compile directly into the kernel

(1) Rename the key.c source code to key_hui.c and put it in the linux-2.6.32/drivers/char directory

(2) Add the key compilation configuration option to the vim Kconfig file in the current directory, as shown below:

config KEYS_MINI2440

tristate "KEY Support for Mini2440 GPIO KEYS--add by youshaohui**"

depends on MACH_MINI2440

default y if MACH_MINI2440

help

This option enables support for key connected to GPIO lines on Mini2440 boards.

(3) Add the compilation of the key.c source code to the Makefile in the directory, vim Makefile, as shown below:

(obj-$(CONFIG_KEYS_MINI2440) += key_hui.o)

(4) Enter make menuconfig/device Drivers/Character devises/ and the menu will

See option [] S2C2410 KEY Driver ---SU, select it.

Open the key_hui.c file, remove the "__init" of the loading function name, and remove the "__exit" of the unloading function name, otherwise the compilation will fail.

Recompile and burn the kernel, burning method.

{

make zImage

Enter the cd /mini2440/linux-2.6.32.2/arch/arm/boot directory and use the u-boot/tools/mkimage tool to add the file headers required for u-boot booting to the kernel:

/mini2440/u-boot-201003/tools/mkimage -n 'linux-2.6.32' -A arm -O linux -T kernel -C none -a 0x30008000 -e 0x30008040 -d zImage uImage.img

//The generated image is in: /mini2440/linux-2.6.32.2/arch/arm/boot

tftp 0x30008000 uImage.img

After downloading, you can burn it into flash

nand erase 0x80000 300000

nand write 0x30008000 0x80000 300000

set bootcmd 'nand read 0x30008000 0x80000 300000;bootm 0x30008000'

saveenv

reset

}

Method 3: Compile the kernel as a module in the kernel

(1) The first few steps are the same as those in method 2, except that (4) changes the option to [M].

(2) Make zImage to generate the kernel. At this time, the kernel does not contain the key driver.

(3) After compiling the kernel, you also need to compile the kernel module #make modules. key_hui.ko will be generated under linux-2.6.32/drivers/char

(4) Install kernel modules:

make modules_install INSTALL_MOD_PATH=/root/build_rootfs/rootfs. At this time, the /root/build_rootfs/rootfs/lib/modules/2.6.32.2-FriendlyARM directory will be created in the file system, and the compiled kernel module will be moved from the kernel source directory to the /lib/modules/2.6.32.2-FriendlyARM/kernel of the specified file system.

(5) Burn the kernel and file system (or use NFS to connect to the development version).

(6) Enter the development board/lib/modules/2.6.32.2-FriendlyARM/kernel/drivers/char. At this time, key_su.ko is in this directory. Then insmod key_su.ko and run the corresponding application.