In the xv6 operating system kernel, system calls are implemented. Select the correct statements about the code implementation describing the transition from user land to kernel land, placement of code in various files, mix of C and assembly code.

(note: this is a multiple choices may be correct type question)

Question

In the xv6 operating system kernel, system calls are implemented. Select the correct statements about the code implementation describing the transition from user land to kernel land, placement of code in various files, mix of C and assembly code.  
 
 (note: this is a multiple choices may be correct type question)

Answer

The SYSCALL macro is used to define the entry point of syscall related userland function like open, read, write, etc.

Answer

There is no Linux like C library on xv6 that defines the system call wrapper functions like read/write/fork/etc in userland.

Answer

The SYSCALL macro is used to store the number of the system call in the eax register.

Answer

Only hardware interrupts execute via the trap() function, and the system calls execute via the syscall() function in xv6 kernel.

Answer

The assembly code is involved only in kernel code, in the execution of a system call on xv6.

Answer

Addition of a new system call requires adding an entry to vectors.S which defines entry points for system calls and also for hardware interrupts.

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In the xv6 operating system kernel, system calls are implemented. Select the cor...

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