Basically, execv do more or less the same thing with runprogram in $OS161_SRC/kern/syscall/runprogram.c. The overall flow of sys_execv are:

1. Copy arguments from user space into kernel buffer
2. Open the executable, create a new address space and load the elf into it
3. Copy the arguments from kernel buffer into user stack
4. Return user mode using enter_new_process

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