supervisor-mode

ARM. Access user R13 and R14 from Supervisor mode

How do I access the user R13 and R14 which are saved when supervisor mode is entered? I am using an ARM7TDMI. I.E. I do not want to access supervisor R14 which now contains the return address to user mode, instead want the value of user mode's link register. This is part of a debugger I am writing. Are there special aliases for these ...

User mode vs supervisor mode

I have a few questions on the user-mode and supervisor-mode on Unix-like machines. What is the difference between user-mode and supervisor-mode? I know that the user processes cannot access all memory and hardware and execute all instructions. Is there more to this? What are the advantages of having different modes? What are the step...

How does Windows switch to supervisor mode during a system call?

How does Windows switch to supervisor mode during a system call? I heard something about a "trap 0", but that doesn't even seem like an x86 instruction. I stepped through some system calls, but I can't find any. Do a lot of Windows system calls run in user mode? Which DO run in supervisor mode? ...