39 lines
1.4 KiB
Rust
39 lines
1.4 KiB
Rust
//! Implementation of syscalls
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//!
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//! The single entry point to all system calls, [`syscall()`], is called
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//! whenever userspace wishes to perform a system call using the `ecall`
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//! instruction. In this case, the processor raises an 'Environment call from
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//! U-mode' exception, which is handled as one of the cases in
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//! [`crate::trap::trap_handler`].
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//!
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//! For clarity, each single syscall is implemented as its own function, named
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//! `sys_` then the name of the syscall. You can find functions like this in
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//! submodules, and you should also implement syscalls this way.
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const SYSCALL_WRITE: usize = 64;
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const SYSCALL_EXIT: usize = 93;
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const SYSCALL_YIELD: usize = 124;
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const SYSCALL_GET_TIME: usize = 169;
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const SYSCALL_SBRK: usize = 214;
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const SYSCALL_MMAP: usize = 222;
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const SYSCALL_MUNMAP: usize = 215;
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mod fs;
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mod process;
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use fs::*;
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use process::*;
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/// handle syscall exception with `syscall_id` and other arguments
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pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
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match syscall_id {
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SYSCALL_WRITE => sys_write(args[0], args[1] as *const u8, args[2]),
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SYSCALL_EXIT => sys_exit(args[0] as i32),
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SYSCALL_YIELD => sys_yield(),
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SYSCALL_GET_TIME => sys_get_time(),
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SYSCALL_SBRK => sys_sbrk(args[0] as i32),
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SYSCALL_MMAP => sys_mmap(args[0], args[1], args[2]),
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SYSCALL_MUNMAP => sys_munmap(args[0], args[1]),
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_ => panic!("Unsupported syscall_id: {}", syscall_id),
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}
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}
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