Hi,
Im a newbie to linux and im trying to do a homework of adding a device to the kernel.
Please point out my mistakes in the forum
I am trying the sample driver memory.c which i net to load into my kernel
my memory.c looks like this
Code:
#include <linux/init.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h> /* printk() */
#include <linux/slab.h> /* kmalloc() */
#include <linux/fs.h> /* everything... */
#include <linux/errno.h> /* error codes */
#include <linux/types.h> /* size_t */
#include <linux/proc_fs.h>
#include <linux/fcntl.h> /* O_ACCMODE */
#include <asm/system.h> /* cli(), *_flags */
#include <asm/uaccess.h> /* copy_from/to_user */
/* Declaration of memory.c functions */
int memory_open(struct inode *inode, struct file *filp);
int memory_release(struct inode *inode, struct file *filp);
ssize_t memory_read(struct file *filp, char *buf, size_t count, loff_t *f_pos);
ssize_t memory_write(struct file *filp, char *buf, size_t count, loff_t *f_pos); void memory_exit(void);
int memory_init(void);
/* Structure that declares the usual file / / access functions */
struct file_operations memory_fops =
{ read: memory_read,
write: memory_write,
open: memory_open,
release: memory_release };
/* Declaration of the init and exit functions */
module_init(memory_init);
module_exit(memory_exit);
/* Global variables of the driver / / Major number */
int memory_major = 60;
/* Buffer to store data */
char *memory_buffer;
/*------------------------------------------------------*/
int memory_init(void)
{
int result;
/* Registering device */
result = register_chrdev(memory_major, "memory", &memory_fops);
if (result < 0)
{
printk( "<1>memory: cannot obtain major number %d\n", memory_major); return result;
}
/* Allocating memory for the buffer */
memory_buffer = kmalloc(1, GFP_KERNEL);
if (!memory_buffer)
{
result = -ENOMEM; goto fail;
}
memset(memory_buffer, 0, 1);
printk("<1>Inserting memory module\n");
return 0;
fail: memory_exit(); return result;
}
/*---------------------------------------------*/
void memory_exit(void)
{
/* Freeing the major number */
unregister_chrdev(memory_major, "memory");
/* Freeing buffer memory */
if (memory_buffer)
{
kfree(memory_buffer);
}
printk("<1>Removing memory module\n");
}
/*-------------------------------*/
int memory_open(struct inode *inode, struct file *filp)
{
/* Success */
return 0;
}
/*-------------------------------*/
int memory_release(struct inode *inode, struct file *filp)
{
/* Success */
return 0;
}
/*-------------------------------*/
ssize_t memory_read(struct file *filp, char *buf,
size_t count, loff_t *f_pos)
{
/* Transfering data to user space */
copy_to_user(buf,memory_buffer,1);
/* Changing reading position as best suits */
if (f_pos == 0)
{
*f_pos+=1; return 1;
}
else
{
return 0;
}
}
/*-------------------------------*/
ssize_t memory_write( struct file *filp, char *buf,
size_t count, loff_t *f_pos)
{
char *tmp;
tmp=buf+count-1; copy_from_user(memory_buffer,tmp,1); return 1;
}
Makefile used is
Code:
obj-m += memory.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
the error im getting is
sathish/sathish-desktop:~$ make memory
cc memory.c -o memory
memory.c:1:24: error: linux/init.h: No such file or directory
memory.c:4:26: error: linux/config.h: No such file or directory
memory.c:7:26: error: linux/module.h: No such file or directory
memory.c:13:40: error: linux/slab.h: No such file or directory
memory.c:25:27: error: linux/proc_fs.h: No such file or directory
In file included from /usr/include/asm/fcntl.h:1,
from /usr/include/linux/fcntl.h:4,
from memory.c:28:
/usr/include/asm-generic/fcntl.h:96: error: expected specifier-qualifier-list before 'pid_t'
memory.c:31:45: error: asm/system.h: No such file or directory
memory.c:34:49: error: asm/uaccess.h: No such file or directory
memory.c:37: error: expected declaration specifiers or '...' before string constant
memory.c:37: warning: data definition has no type or storage class
memory.c:41: warning: 'struct file' declared inside parameter list
memory.c:41: warning: its scope is only this definition or declaration, which is probably not what you want
memory.c:41: warning: 'struct inode' declared inside parameter list
memory.c:42: warning: 'struct file' declared inside parameter list
memory.c:42: warning: 'struct inode' declared inside parameter list
memory.c:43: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'memory_read'
memory.c:44: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'memory_write'
memory.c:49: error: variable 'memory_fops' has initializer but incomplete type
memory.c:50: error: unknown field 'read' specified in initializer
memory.c:50: error: 'memory_read' undeclared here (not in a function)
memory.c:50: warning: excess elements in struct initializer
memory.c:50: warning: (near initialization for 'memory_fops')
memory.c:51: error: unknown field 'write' specified in initializer
memory.c:51: error: 'memory_write' undeclared here (not in a function)
memory.c:51: warning: excess elements in struct initializer
memory.c:51: warning: (near initialization for 'memory_fops')
memory.c:52: error: unknown field 'open' specified in initializer
memory.c:52: warning: excess elements in struct initializer
memory.c:52: warning: (near initialization for 'memory_fops')
memory.c:53: error: unknown field 'release' specified in initializer
memory.c:53: warning: excess elements in struct initializer
memory.c:53: warning: (near initialization for 'memory_fops')
memory.c:57: warning: data definition has no type or storage class
memory.c:57: warning: parameter names (without types) in function declaration
memory.c:58: warning: data definition has no type or storage class
memory.c:58: warning: parameter names (without types) in function declaration
memory.c: In function 'memory_init':
memory.c:81: error: 'GFP_KERNEL' undeclared (first use in this function)
memory.c:81: error: (Each undeclared identifier is reported only once
memory.c:81: error: for each function it appears in.)
memory.c:86: warning: incompatible implicit declaration of built-in function 'memset'
memory.c: At top level:
memory.c:116: warning: 'struct file' declared inside parameter list
memory.c:116: warning: 'struct inode' declared inside parameter list
memory.c:116: error: conflicting types for 'memory_open'
memory.c:41: note: previous declaration of 'memory_open' was here
memory.c:125: warning: 'struct file' declared inside parameter list
memory.c:125: warning: 'struct inode' declared inside parameter list
memory.c:125: error: conflicting types for 'memory_release'
memory.c:42: note: previous declaration of 'memory_release' was here
memory.c:136: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'memory_read'
memory.c:158: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'memory_write'
make: *** [memory] Error 1
sathish/sathish-desktop:~$
Please let me know the reason for this error , i tried
sudo apt-get update
but in vain.
Thanks in advance.
