Lexicon Entry
svc (Supervisor Call)
See System Call (syscall / svc). On ARM64 architectures, the `svc #0` (or `svc #0x80` on macOS) instruction is used to switch the CPU to kernel mode and request a system service.
Related Knowledge & Cross-References
Build a Debugger from Scratch: Ultimate 3 OS Guide (Part 8)
Understanding the bridge between your code and the kernel is the final key to demystifying how software works. Up to this point in my Assembly Series, you've mastered how to load a process, how calling conventions manage functions, how memory is laid out, and finally, how to talk directly to the hardware via system calls.
System Calls Demystified: 4 Essential Facts About the User-Kernel Bridge
How does your program actually *do* anything? We dive deep into the `syscall` instruction, kernel mode transitions, and the differences between Linux, macOS, and Windows system calls.
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