yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/sources/meta-elmo$ mkdir recipes-kernel
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/sources/meta-elmo$ mkdir recipes-kernel/chardriver
2.建立bb文件
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/sources/meta-elmo/recipes-kernel/chardriver$ vi chardriver_0.1.bb
#yocto recipe to build a kernel module out of the kernel tree
DESCRIPTION = "Chardriver kernel module out of the kernel tree"
LICENSE = "CLOSED"
PROVIDES = "virtual/kernel-module-chardriver"
RPROVIDES_${PN} = "virtual/kernel-module-driver"
RPROVIDES_${PN}-dev = "virtual/kernel-module-driver"
#PR = "r0"
inherit module
SRC_URI = "file://chardriver.c \
file://Makefile \
"
S = "${WORKDIR}"
~
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/sources/meta-elmo/recipes-kernel/chardriver$ mkdir files
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/sources/meta-elmo/recipes-kernel/chardriver$ vi files/Makefile
obj-m := chardriver.o
SRC := $(shell pwd)
all:
$(MAKE) -C $(KERNEL_SRC) M=$(SRC)
modules_install:
$(MAKE) -C $(KERNEL_SRC) M=$(SRC) modules_install
clean:
rm -f *.o *~ core .depend .*.cmd *.ko *.mod.c
rm -f Module.markers Module.symvers modules.order
rm -rf .tmp_versions Modules.symvers
4.编写驱动C文件
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/cdev.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/device.h>
#define simple_MAJOR 200
static unsigned char simple_inc=0;
static char demoBuffer[256];
int simple_open(struct inode *inode,struct file *filp)
{
if(simple_inc>0) return -ERESTARTSYS;
simple_inc++;
memset(demoBuffer,0,256);
return 0;
}
int simple_release(struct inode *inode,struct file *filp)
{
if(simple_inc<=0){
printk("close error");
return -EFAULT;
}
simple_inc--;
return 0;
}
ssize_t simple_read(struct file *filp,char __user *buf,size_t count,loff_t *f_pos)
{
if(copy_to_user(buf,demoBuffer,count)){
count=-EFAULT;
}
return count;
}
size_t simple_write(struct file *file,const char __user *buf,size_t count,loff_t *f_pos)
{
if (copy_from_user(demoBuffer + *f_pos,buf,count)){
count = -EFAULT;
}
return count;
}
static const struct file_operations simple_fops={
.owner=THIS_MODULE,
.open=simple_open,
.release=simple_release,
.read=simple_read,
.write=simple_write,
};
int simple_init_module(void)
{
int ret;
struct class *simple_class;
memset(demoBuffer,0,256);
ret=register_chrdev(simple_MAJOR,"simple",&simple_fops);
if(ret<0){
printk("Unable to register character device %d!/n",simple_MAJOR);
return ret;
}
simple_class = class_create(THIS_MODULE, "simple_driver");
device_create(simple_class, NULL, MKDEV(simple_MAJOR,0), NULL, "simple_device");
printk("simple_init_module OK!\n");
return 0;
}
void simple_cleanup_module(void)
{
unregister_chrdev(simple_MAJOR,"simple");
printk("simple_cleanup_module!\n");
}
module_init(simple_init_module);
module_exit(simple_cleanup_module);
MODULE_LICENSE("Dual BSD/GPL");
5.编译
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ bitbake chardriver
Loading cache: 100% |###################################################################################################################################| ETA: 00:00:00
Loaded 2567 entries from dependency cache.
Parsing recipes: 100% |#################################################################################################################################| Time: 00:00:00
Parsing of 2051 .bb files complete (2050 cached, 1 parsed). 2566 targets, 157 skipped, 3 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies
Build Configuration:
BB_VERSION = "1.26.0"
BUILD_SYS = "x86_64-linux"
NATIVELSBSTRING = "Ubuntu-14.04"
TARGET_SYS = "arm-poky-linux-gnueabi"
MACHINE = "imx6ulevk"
DISTRO = "poky"
DISTRO_VERSION = "1.8"
TUNE_FEATURES = "arm armv7a vfp neon callconvention-hard cortexa7"
TARGET_FPU = "vfp-neon"
meta
meta-yocto = "(nobranch):83aa565d93aacae484976562ef1ae8dbbb6b2bc0"
meta-oe
meta-multimedia = "(nobranch):10d3c8f85280a0bf867a8e4f84bcda81c290d28e"
meta-fsl-arm = "(nobranch):c5326c90d6754c8630504ae29244907b0841c3a9"
meta-fsl-arm-extra = "(nobranch):436b86e3421736216412bdbb21cd9cb08c758c75"
meta-fsl-demos = "(nobranch):836bdf5a9d500ed258f1ddc07d89eca74a704098"
meta-bsp
meta-sdk = "(nobranch):2f59ef1080f616f391b1c488fb2204e570f90239"
meta-browser = "(nobranch):4b27058a8275a5310161459c9bb8f4c52a77762c"
meta-gnome
meta-networking
meta-python
meta-ruby
meta-filesystems = "(nobranch):10d3c8f85280a0bf867a8e4f84bcda81c290d28e"
meta-qt5 = "(nobranch):fc026381545650e10fdd488d5b2a3b2d78f87793"
meta-elmo = "<unknown>:<unknown>"
NOTE: Preparing RunQueue
NOTE: Executing SetScene Tasks
NOTE: Executing RunQueue Tasks
NOTE: Tasks Summary: Attempted 434 tasks of which 420 didn't need to be rerun and all succeeded.
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$
编译过程文件在tmp/work/imx6ulevk-poky-linux-gnueabi/chardriver/0.1-r0/
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ ls tmp/work/imx6ulevk-poky-linux-gnueabi/chardriver/0.1-r0/
built-in.o chardriver.ko chardriver.mod.o chardriver.spec deploy-rpms license-destdir modules.order package pkgdata sysroot-destdir
chardriver.c chardriver.mod.c chardriver.o configure.sstate image Makefile Module.symvers packages-split pseudo temp
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$
查看tmp/work/imx6ulevk-poky-linux-gnueabi/chardriver/0.1-r0/chardriver.c 是跟我们写的驱动是一样的。
现在驱动编译是OK了，但查看镜像却没有我们的驱动，也是因为我们没把驱动加入系统
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ sudo mount -o loop -t ext3 tmp/deploy/images/imx6ulevk/fsl-image-qt5-imx6ulevk.ext3 /home/work/rootfs/
[sudo] password for yangzhiwen:
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ ls /home/work/rootfs/lib/modules/3.14.38-6UL_ga+ge4944a5/extra/
cryptodev.ko
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$
6.现在我们添加驱动
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ vi ../sources/meta-elmo/conf/layer.conf
# We have a conf and classes directory, add to BBPATH
BBPATH .= ":${LAYERDIR}"
# We have recipes-* directories, add to BBFILES
BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
${LAYERDIR}/recipes-*/*/*.bbappend"
MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "chardev" #添加此2行代码，此行表示将驱动编译进系统，下面那行表示系统运行里加载驱动
KERNEL_MODULE_AUTOLOAD += "chardev"
IMAGE_INSTALL_append = "elmo-example"
BBFILE_COLLECTIONS += "elmo"
BBFILE_PATTERN_elmo = "^${LAYERDIR}/"
BBFILE_PRIORITY_elmo = "6"
~
7.再编译和查看
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ bitbake fsl-image-qt5
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ ls tmp/work/imx6ulevk-poky-linux-gnueabi/chardev/1.0-r0/
built-in.o configure.sstate image package pseudo sstate-install-package_qa sstate-install-populate_sysroot
chardev.c COPYING license-destdir packages-split sstate-install-package sstate-install-package_write_rpm sysroot-destdir
chardev.spec deploy-rpms Makefile pkgdata sstate-install-packagedata sstate-install-populate_lic temp
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ sudo mount -o loop -t ext3 tmp/deploy/images/imx6ulevk/fsl-image-qt5-imx6ulevk-20160127022253.rootfs.ext3 /home/data/rootfs/
yangzhiwen@yzw-kingsee:/home/work/workspace/fsl-release-bsp/build_qt5$ ls /home/data/rootfs/lib/modules/3.14.38-6UL_ga+ge4944a5/extra/
chardev.ko cryptodev.ko
8.烧录到卡后log
Starting udev
udevd[156]: starting version 182
random: nonblocking pool is initialized
FAT-fs (mmcblk1p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.
simple_init_module OK!
OK
https://blog.csdn.net/yangzhiwen56/article/details/50592845?locationNum=13
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