2022-05-23 17:42:11 +01:00
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---
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2022-09-06 13:26:44 +01:00
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tags:
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2024-06-15 11:30:03 +01:00
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- operating-systems
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2026-01-31 12:21:49 +00:00
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- linux
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2022-05-23 17:42:11 +01:00
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---
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2026-01-31 12:21:49 +00:00
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# Basic model of a \*nix operating system
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2022-05-23 17:42:11 +01:00
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2024-02-02 15:58:13 +00:00
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We can abstract the Linux OS into three operational levels or tiers, from the
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bottom up:
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2022-05-23 17:42:11 +01:00
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2026-01-31 12:21:49 +00:00
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- **User processes: user space**
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- The running programs that the kernel manages. Also known as the user space
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which is the memory that the kernel assigns for user processes. Comprising:
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- Graphical user interface
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- Servers
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- Shell
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2022-05-23 18:30:04 +01:00
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2026-01-31 12:21:49 +00:00
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- **Kernel: kernel space**
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- The core of the operating system. Software residing in memory that tells the
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CPU where to look for its next task. Acts as a mediator and primary
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interface between the hardware and the user processes. Known as kernel
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space: the memory that the kernel allocates for itself. Comprising:
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- System calls
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- Process management
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- Memory management
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- Device drivers
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- **Hardware**
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- The base: one or more CPUs and RAM memory performing computations and
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writing to memory. Comprising:
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- Processor (CPU)
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- Main memory (RAM)
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- Disks
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- Network ports
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