Escreva seu primeiro
MDULO DE KERNEL
(LINUX)
Em quatro atos
Hello World!
Character driver
Miscellaneous driver
Ramdisk
0 Hello World
Ol mundo!
Diego Ramos Ruggeri
http://vai.la/62u3
0 Hello World
Linux monoltico
Mdulos carregados em tempo de execuo
Ciclo de vida
Bsico: Inicializar e Limpar
0 Hello World
Porque?Hardware livre
Entender o Linux
OOP em C
Projeto de software livre
static int __init hello_module(void){printk(KERN_INFO "Hello
World!\n");return 0;}
static void __exit goodbye_module(void){printk(KERN_INFO
"Adios\n");}
module_init(hello_module);module_exit(goodbye_module);
MODULE_LICENSE("GPL");MODULE_AUTHOR("Diego
Ruggeri");MODULE_DESCRIPTION("Hello World module");
0 Hello World
obj-m += hello.o
all:make -C /lib/modules/$(shell uname -r)/build M=$(PWD)
modules
clean:make -C /lib/modules/$(shell uname -r)/build M=$(PWD)
clean
0 Hello World
modinfo
insmod
lsmod
rmmod
dmesg
1 Char Dev
ioctls
net
/dev
/sys
/devBlock device
Character device
Major Minor
static struct file_operations fops = {.read = device_read,.write
= device_write,.open = device_open,.release = device_release};
static int __init hello_module(void){major = register_chrdev(0,
DEVICE, &fops);/* */}
static void __exit goodbye_module(void){unregister_chrdev(major,
DEVICE);}
2 Misc Dev
mknod /dev/fisl15 c $MAJOR $MINOR
udev
Miscellaneous API
static struct file_operations fops = { /*...*/ };static struct
miscdevice mdev = { .minor = MISC_DYNAMIC_MINOR, .name = DEVICE,
.fops = &fops,};
static int __init hello_module(void){misc_register(&mdev)/*
*/}
static void __exit
goodbye_module(void){misc_deregister(&mdev);}
3 - Ramdisk
Char device +
Misc api +
Aloca memria (slab) +
open, close, read, write
static int __init hello_module(void){disk = (char*)
kzalloc(DISK_SIZE * sizeof(char), GFP_KERNEL);/**/}
static void __exit goodbye_module(void){kfree(disk);/*...*/}
static ssize_t device_read(struct file *filp, char *buffer,
size_t length,loff_t * offset){/*...*/copy_to_user(buffer, message,
len);/*...*/}
static ssize_t device_write(struct file *filp, const char *buff,
size_t len, loff_t * off){copy_from_user(disk, buff, len)}
Obrigado
[email protected]://github.com/diegor2
