linux kernel Programming一些知识

Programming方面的一些知识：

1. By convention, all kernel prefixes are lowercase.

2. The file /proc/kallsyms holds all the symbols that the kernel knows about and which are therefore accessible

to your modules since they share the kernel's codespace.

3. 结构体赋值方法的不同

GCC:

struct file_operations fops = {

read: device_read,

write: device_write,

open: device_open,

release: device_release

};

C99:

struct file_operations fops = {

.read = device_read,

.write = device_write,

.open = device_open,

.release = device_release

};

4. Normally a negative return value means the registration failed

5. major number分配方法

a. major number can be dynamically assigned by kernel.

b. must look throught documenet/devices.txt and then get an unused one

6. /proc/modules which provides the list of modules

   /proc/meminfo which stats memory usage statistics