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impl translate

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This commit is contained in:
Moysan Gabriel 2023-03-15 00:32:58 +01:00
parent ea309ab124
commit 77f28d029d
2 changed files with 39 additions and 6 deletions
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2
src/simulator/machine.rs
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@ -15,7 +15,7 @@ pub enum ExceptionType {
//SYSCALL_EXCEPTION,//A program executed a system call.
PAGEFAULT_EXCEPTION,//Page fault exception
READONLY_EXCEPTION,//Write attempted to a page marked "read-only" */
//BUSERROR_EXCEPTION,
BUSERROR_EXCEPTION,
/* translation resulted
in an invalid physical
address (mis-aligned or

43
src/simulator/mmu.rs
View File

@ -1,8 +1,6 @@
use crate::simulator::translationtable::*;
use crate::simulator::machine::*;
use super::machine::ExceptionType;
pub struct MMU <'a>{
/* Un MMU possède une seule référence vers une table des pages à un instant donné
* Cette table est associée au processus courant
@ -20,14 +18,35 @@ impl <'a>MMU <'_>{
}
}
fn translate(mmu : &mut MMU, virtAddr : u64, physAddr : &mut u64, size : usize, writing : bool) -> ExceptionType {
pub fn mmu_read_mem(mmu : &mut MMU, machine : &Machine, virt_addr : u64, value : &mut u64) -> bool {
//Pour plus tard eventuellement considerer le boutisme de notre mémoire
//Peut etre pas si on fixe cela en BIG ENDIAN (octects poids fort au debut)
let mut phy_addr : u64 = 0;
let mut phy_addr_double_check : u64 = 0;
let exc = MMU::translate(mmu, virt_addr, &mut phy_addr, false);
MMU::translate(mmu, virt_addr, &mut phy_addr_double_check, false);
//PB ICI car double appel a translate et on doit a chaque appel passer mmu en param
true
}
pub fn mmu_write_mem(&mut self, machine : &mut Machine, virt_addr : u64, value : &mut u64) -> bool {
//Pour plus tard eventuellement considerer le boutisme de notre mémoire
//Peut etre pas si on fixe cela en BIG ENDIAN (octects poids fort au debut)
true
}
pub fn translate(mmu : &mut MMU, virtAddr : u64, physAddr : &mut u64, writing : bool) -> ExceptionType {
let vpn : u64 = virtAddr/PAGE_SIZE; //virtual page index
let offset : u64 = virtAddr%PAGE_SIZE; //adresse intra page
match &mmu.translationTable {
match &mut mmu.translationTable {
None => {
println!("Error from translate : MMU refers to None (No page Table)");
return ExceptionType::ADDRESSERROR_EXCEPTION;
@ -67,7 +86,21 @@ impl <'a>MMU <'_>{
}
//Make sure that the physical adress is correct
let num_phy_page = (MEM_SIZE as u64)/PAGE_SIZE;
if table_ref.get_physical_page(vpn) < 0 || table_ref.get_physical_page(vpn) >= (NUM_PHY_PAGE as i32) {
println!("Error from translate :: no valid correspondance");
return ExceptionType::BUSERROR_EXCEPTION;
}
//Set U/M bits to 1
if writing {
table_ref.set_bit_M(vpn);
}
table_ref.set_bit_U(vpn);
//on se permet ici la conversion du champs physical_page de i32 vers u64
//si cette valeur avait été signée, cela aurait été detecté juste au dessus, renvoyant une BUSERROR_EXCEPTION
*physAddr = (table_ref.get_physical_page(vpn) as u64)*PAGE_SIZE + offset;
}
}