Kernel library crate for xous
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xous-kernel/src/processtable.rs

65 lines
2.1 KiB

use crate::definitions::{MemoryAddress, XousError, XousPid};
use crate::mem::MemoryManager;
use crate::{filled_array, print, println};
use vexriscv::register::{mstatus, satp};
const MAX_PROCESS_COUNT: usize = 256;
pub struct Process {
pub satp: usize,
}
impl core::fmt::Debug for Process {
fn fmt(&self, fmt: &mut core::fmt::Formatter) -> core::result::Result<(), core::fmt::Error> {
write!(
fmt,
"Process (satp: 0x{:08x}, mode: {}, ASID: {}, PPN: {:08x})",
self.satp,
self.satp >> 31,
self.satp >> 22 & ((1 << 9) - 1),
(self.satp >> 0 & ((1 << 22) - 1)) << 9,
)
}
}
pub struct ProcessTable {
processes: [Process; MAX_PROCESS_COUNT],
}
extern "Rust" {
fn start_kmain(
kmain: extern "Rust" fn(MemoryManager, ProcessTable) -> !,
mm: MemoryManager,
pt: ProcessTable,
) -> !;
}
impl ProcessTable {
pub fn new(mut mm: MemoryManager, kmain: fn(MemoryManager, ProcessTable) -> !) -> ! {
let mut pt = ProcessTable {
processes: filled_array![Process { satp: 0 }; 256],
};
// Allocate a root page table for PID 1. Also mark the "ASID" as "1"
// for "PID 1"
let root_page = mm.alloc_page(1).unwrap().get();
pt.processes[1].satp = (root_page >> 9) | (1 << 22);
mm.create_identity(&pt.processes[1])
.expect("Unable to create identity mapping");
println!("PID 1: {:?} root page @ {:08x}", pt.processes[1], root_page);
println!("Enabling MMU...");
unsafe {
// Set the MMU pointer to our identity mapping
satp::set(
satp::Mode::Sv32,
(pt.processes[1].satp >> 22) & ((1 << 9) - 1),
(pt.processes[1].satp >> 0) & ((1 << 22) - 1),
);
// Switch to Supervisor mode
mstatus::set_mpp(mstatus::MPP::Supervisor);
};
println!("MMU enabled, jumping to kmain");
unsafe { start_kmain(kmain, mm, pt) }
}
}