This is the end of the first part about linux kernel initialization.
If you have questions or suggestions, feel free to ping me in twitter [0xAX](https://twitter.com/0xAX), drop me [email](anotherworldofworld@gmail.com) or just create [issue](https://github.com/0xAX/linux-internals/issues/new).
If you have questions or suggestions, feel free to ping me in twitter [0xAX](https://twitter.com/0xAX), drop me [email](anotherworldofworld@gmail.com) or just create [issue](https://github.com/0xAX/linux-insides/issues/new).
In the next part we will see initialization of the early interruption handlers, kernel space memory mapping and a lot more.
**Please note that English is not my first language and I am really sorry for any inconvenience. If you found any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-insides).**
**Please note that English is not my first language and I am really sorry for any inconvenience. If you found any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-insides).**
@ -444,7 +444,7 @@ It is the end of the tenth part about the linux kernel [initialization process](
If you will have any questions or suggestions write me a comment or ping me at [twitter](https://twitter.com/0xAX).
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-internals).**
This is the end of the second part about linux kernel internals. If you have questions or suggestions, ping me in twitter [0xAX](https://twitter.com/0xAX), drop me [email](anotherworldofworld@gmail.com) or just create [issue](https://github.com/0xAX/linux-internals/issues/new). In the next part we will see all steps before kernel entry point - `start_kernel` function.
This is the end of the second part about linux kernel insides. If you have questions or suggestions, ping me in twitter [0xAX](https://twitter.com/0xAX), drop me [email](anotherworldofworld@gmail.com) or just create [issue](https://github.com/0xAX/linux-internals/issues/new). In the next part we will see all steps before kernel entry point - `start_kernel` function.
**Please note that English is not my first language and I am really sorry for any inconvenience. If you found any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language and I am really sorry for any inconvenience. If you found any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-internals).**
It is the end of the third part about linux kernel internals. In next part we will see the first initialization steps in the kernel entry point - `start_kernel` function. It will be the first step before we will see launch of the first `init` process.
It is the end of the third part about linux kernel insides. In next part we will see the first initialization steps in the kernel entry point - `start_kernel` function. It will be the first step before we will see launch of the first `init` process.
If you have any questions or suggestions write me a comment or ping me at [twitter](https://twitter.com/0xAX).
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-internals).**
@ -436,7 +436,7 @@ It is the end of the fourth part about the Linux kernel initialization process.
If you will have any questions or suggestions write me a comment or ping me at [twitter](https://twitter.com/0xAX).
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me a PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me a PR to [linux-insides](https://github.com/0xAX/linux-internals).**
@ -494,7 +494,7 @@ It is the end of the fifth part about linux kernel initialization process. In th
If you will have any questions or suggestions write me a comment or ping me at [twitter](https://twitter.com/0xAX).
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-internals).**
@ -528,7 +528,7 @@ It is the end of the sixth part about linux kernel initialization process. In th
If you will have any questions or suggestions write me a comment or ping me at [twitter](https://twitter.com/0xAX).
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-internals).**
This is the seventh parth of the Linux Kernel initialization process which covers internals of the `setup_arch` function from the [arch/x86/kernel/setup.c](https://github.com/torvalds/linux/blob/master/arch/x86/kernel/setup.c#L861). As you can know from the previous [parts](http://0xax.gitbooks.io/linux-insides/content/Initialization/index.html), the `setup_arch` function does some architecture-specific (in our case it is [x86_64](http://en.wikipedia.org/wiki/X86-64)) initialization stuff like reserving memory for kernel code/data/bss, early scanning of the [Desktop Management Interface](http://en.wikipedia.org/wiki/Desktop_Management_Interface), early dump of the [PCI](http://en.wikipedia.org/wiki/PCI) device and many many more. If you have read the previous [part](http://0xax.gitbooks.io/linux-insides/content/Initialization/%20linux-initialization-6.html), you can remember that we've finished it at the `setup_real_mode` function. In the next step, as we set limit of the [memblock](http://0xax.gitbooks.io/linux-insides/content/mm/linux-mm-1.html) to the all mapped pages, we can see the call of the `setup_log_buf` function from the [kernel/printk/printk.c](https://github.com/torvalds/linux/blob/master/kernel/printk/printk.c).
This is the seventh parth of the Linux Kernel initialization process which covers insides of the `setup_arch` function from the [arch/x86/kernel/setup.c](https://github.com/torvalds/linux/blob/master/arch/x86/kernel/setup.c#L861). As you can know from the previous [parts](http://0xax.gitbooks.io/linux-insides/content/Initialization/index.html), the `setup_arch` function does some architecture-specific (in our case it is [x86_64](http://en.wikipedia.org/wiki/X86-64)) initialization stuff like reserving memory for kernel code/data/bss, early scanning of the [Desktop Management Interface](http://en.wikipedia.org/wiki/Desktop_Management_Interface), early dump of the [PCI](http://en.wikipedia.org/wiki/PCI) device and many many more. If you have read the previous [part](http://0xax.gitbooks.io/linux-insides/content/Initialization/%20linux-initialization-6.html), you can remember that we've finished it at the `setup_real_mode` function. In the next step, as we set limit of the [memblock](http://0xax.gitbooks.io/linux-insides/content/mm/linux-mm-1.html) to the all mapped pages, we can see the call of the `setup_log_buf` function from the [kernel/printk/printk.c](https://github.com/torvalds/linux/blob/master/kernel/printk/printk.c).
The `setup_log_buf` function setups kernel cyclic buffer which length depends on the `CONFIG_LOG_BUF_SHIFT` configuration option. As we can read from the documentation of the `CONFIG_LOG_BUF_SHIFT` it can be between `12` and `21`. In the internals, buffer defined as array of chars:
The `setup_log_buf` function setups kernel cyclic buffer which length depends on the `CONFIG_LOG_BUF_SHIFT` configuration option. As we can read from the documentation of the `CONFIG_LOG_BUF_SHIFT` it can be between `12` and `21`. In the insides, buffer defined as array of chars:
```C
#define __LOG_BUF_LEN (1 <<CONFIG_LOG_BUF_SHIFT)
@ -462,7 +462,7 @@ It is the end of the seventh part about the linux kernel initialization process.
If you will have any questions or suggestions write me a comment or ping me at [twitter](https://twitter.com/0xAX).
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-internals).**
@ -458,7 +458,7 @@ and other initialization stuff in the next part.
If you will have any questions or suggestions write me a comment or ping me at [twitter](https://twitter.com/0xAX).
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-internals).**
@ -409,7 +409,7 @@ It is the end of the ninth part about the linux kernel [initialization process](
If you will have any questions or suggestions write me a comment or ping me at [twitter](https://twitter.com/0xAX).
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-internals](https://github.com/0xAX/linux-internals).**
**Please note that English is not my first language, And I am really sorry for any inconvenience. If you will find any mistakes please send me PR to [linux-insides](https://github.com/0xAX/linux-internals).**
mudongliang
9 years ago