runtime: add mem_protect

This commit is contained in:
Astro 2020-06-28 22:26:52 +02:00
parent 8d1b9f7f23
commit d62a89281d
3 changed files with 48 additions and 3 deletions

View File

@ -17,19 +17,23 @@ MEMORY
SECTIONS
{
.text :
.text : ALIGN(0x1000000)
{
__text_start = .;
KEEP(*(.text.exceptions));
*(.text.boot);
*(.text .text.*);
__text_end = .;
} > SDRAM
.rodata : ALIGN(4)
.rodata : ALIGN(0x1000000)
{
__rodata_start = .;
*(.rodata .rodata.*);
__rodata_end = .;
} > SDRAM
.data : ALIGN(4)
.data : ALIGN(0x1000000)
{
*(.data .data.*);
} > SDRAM

View File

@ -11,6 +11,7 @@ use log::{info, error};
use libboard_zynq::{timer::GlobalTimer, logger, devc};
use libsupport_zynq::ram;
mod mem_protect;
mod sd_reader;
mod config;
mod proto_core_io;
@ -44,6 +45,7 @@ pub fn main_core0() {
log::set_max_level(log::LevelFilter::Debug);
info!("NAR3/Zynq7000 starting...");
mem_protect::setup();
ram::init_alloc_linker();
match config::Config::new() {

View File

@ -0,0 +1,39 @@
use libcortex_a9::mmu::{AccessPermissions, L1_PAGE_SIZE, L1Table};
/// Symbols defined by the linker script
extern "C" {
static __text_start: usize;
static __text_end: usize;
static __rodata_start: usize;
static __rodata_end: usize;
}
/// Apply basic memory protection to the regions defined by the linker
/// script for the runtime on core 0.
///
/// Therefore these regions need to be aligned to 1 MB.
pub fn setup() {
let text_start = unsafe { &__text_start as *const _ as usize };
let text_end = unsafe { &__text_end as *const _ as usize };
let rodata_start = unsafe { &__rodata_start as *const _ as usize };
let rodata_end = unsafe { &__rodata_end as *const _ as usize };
let l1table = L1Table::get();
for addr in (0..0xFFFF_FFFF).step_by(L1_PAGE_SIZE) {
l1table.update(addr as *const usize, |l1section| {
if addr >= text_start && addr < text_end {
// Code: R-X
l1section.access = AccessPermissions::ReadOnly;
l1section.exec = true;
} else if addr >= rodata_start && addr < rodata_end {
// Data: R--
l1section.access = AccessPermissions::ReadOnly;
l1section.exec = false;
} else {
// Everything else: RW-
l1section.access = AccessPermissions::FullAccess;
l1section.exec = false;
}
});
}
}