rcore-tutorial/os/src/trap/context.rs
2021-02-28 06:38:13 +08:00

37 lines
872 B
Rust

use riscv::register::sstatus::{Sstatus, self, SPP};
#[repr(C)]
#[derive(Debug)]
pub struct TrapContext {
pub x: [usize; 32],
pub sstatus: Sstatus,
pub sepc: usize,
pub kernel_satp: usize,
pub kernel_sp: usize,
pub trap_handler: usize,
}
impl TrapContext {
pub fn set_sp(&mut self, sp: usize) { self.x[2] = sp; }
pub fn app_init_context(
entry: usize,
sp: usize,
kernel_satp: usize,
kernel_sp: usize,
trap_handler: usize,
) -> Self {
let mut sstatus = sstatus::read();
// set CPU privilege to User after trapping back
sstatus.set_spp(SPP::User);
let mut cx = Self {
x: [0; 32],
sstatus,
sepc: entry,
kernel_satp,
kernel_sp,
trap_handler,
};
cx.set_sp(sp);
cx
}
}