What is the difference between user and kernel modes in operating systems?

Kernel Mode In Kernel mode, the executing code has complete and unrestricted access to the underlying hardware. It can execute any CPU instruction and reference any memory address. Kernel mode is generally reserved for the lowest-level, most trusted functions of the operating system. Crashes in kernel mode are catastrophic; they will halt the entire PC. … Read more

What are some resources for getting started in operating system development? [closed]

There are a lot of links after this brief overview of what is involved in writing an OS for the X86 platform. The link that appears to be most promising (www.nondot.org/sabre/os/articles) is no longer available, so you’ll need to poke through the Archive.org version to read it. At the end of the day the bootloader … Read more

Difference between binary semaphore and mutex

They are NOT the same thing. They are used for different purposes! While both types of semaphores have a full/empty state and use the same API, their usage is very different. Mutual Exclusion Semaphores Mutual Exclusion semaphores are used to protect shared resources (data structure, file, etc..). A Mutex semaphore is “owned” by the task … Read more

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