Kernel 0.0.1 Walkthrough.
Downloading Kernel 0.01 and exploding the archive, you're faced with a directory "linux" containing, in subdirectories, some 5900 lines of (more or less) ANSI C, around 2500 lines of C headers (#include files) and around 1450 lines of i386 assembler.
The linux 0.01 kernel source is at http://www.kernel.org/pub/linux/kernel/Historic/
The code directories are as follows. Click on the Details column for more information.
Name |
Purpose |
Details |
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boot |
Kernel bootstrap code |
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fs |
File system |
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include |
Header files |
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init |
init process-the first process executed by a UNIX system |
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kernel |
System calls |
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lib |
Library code |
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mm |
Memory management |
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tools |
Program that splices three images together into a kernel image that can be booted from PC BIOS startup |
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The header files are not the standard header files, because when you're working on a kernel you don't have the luxury of the usual C functions--you have to write your own versions.
The kernel directory contains most of the system functions, but some of them (like sys_fcntl()) are in the file system directory.
The kernel bootup goes through three steps.