juju/JuliOS
1
0
Fork 0
Code Issues 12 Pull Requests Projects Releases Wiki Activity

Compare commits

base: juju:2433d99bc7dfbfd9fb8f1939b4c98f792d98c32e
Branches Tags
juju:master
juju:yield_executor
..
compare: juju:5e994b9dff7242c59cf23b3d20882ce093b68bf4
Branches Tags
juju:master
juju:yield_executor

No commits in common. "2433d99bc7dfbfd9fb8f1939b4c98f792d98c32e" and "5e994b9dff7242c59cf23b3d20882ce093b68bf4" have entirely different histories.
2433d99bc7 ... 5e994b9dff

4 changed files with 70 additions and 150 deletions
Show Stats Expand all files Collapse all files

37
src/lib.rs
View File

@ -11,8 +11,6 @@ mod vga;
extern crate multiboot2;
use core::panic::PanicInfo;
use memory::paging::{FrameAllocator, Size4KiB};
use multiboot2::BootInformation;
use vga::{Color, ColorCode};
#[panic_handler]
@ -28,33 +26,14 @@ pub fn hlt_loop() -> ! {
}
}
pub fn init<A>(frame_allocator: &mut A, boot_info: &BootInformation)
where
A: FrameAllocator<Size4KiB>,
{
pub fn init() {
vga::change_color(ColorCode::new(Color::LightCyan, Color::Black));
println!("Starting init");
enable_nxe_bit();
enable_write_protect_bit();
memory::kernel_remap(frame_allocator, boot_info);
gdt::init_gdt();
interrupts::init_idt();
vga::change_color(ColorCode::new(Color::LightGreen, Color::Black));
}
fn enable_nxe_bit() {
println!("Enabling nxe bit");
use x86_64::registers::control::{Efer, EferFlags};
unsafe { Efer::update(|efer| *efer |= EferFlags::NO_EXECUTE_ENABLE) }
}
fn enable_write_protect_bit() {
println!("Enabling write protection bit");
use x86_64::registers::control::{Cr0, Cr0Flags};
unsafe { Cr0::write(Cr0::read() | Cr0Flags::WRITE_PROTECT) };
}
fn get_frame_allocator(multiboot_info_addr: usize) -> memory::AreaFrameAllocator {
let boot_info = unsafe { multiboot2::load(multiboot_info_addr) };
let memory_map_tag = boot_info.memory_map_tag().expect("Memory map tag required");
@ -73,13 +52,8 @@ fn get_frame_allocator(multiboot_info_addr: usize) -> memory::AreaFrameAllocator
let multiboot_start: u64 = multiboot_info_addr as u64;
let multiboot_end: u64 = multiboot_start + (boot_info.total_size as u64);
memory::AreaFrameAllocator::new(
kernel_start,
kernel_end,
multiboot_start,
multiboot_end,
memory_map_tag.memory_areas(),
)
memory::AreaFrameAllocator::new( kernel_start, kernel_end, multiboot_start,
multiboot_end, memory_map_tag.memory_areas())
}
#[no_mangle]
@ -88,8 +62,11 @@ pub extern "C" fn julios_main(multiboot_info_addr: usize) -> ! {
let mut frame_allocator = get_frame_allocator(multiboot_info_addr);
init(&mut frame_allocator, &boot_info);
memory::kernel_remap(&mut frame_allocator, boot_info);
init();
println!("***JuliOS V0.1.0***");
serial_println!("Hello serial");
memory::paging::test_paging(&mut frame_allocator);
panic!("Kernel end of flow");
}

11
src/memory/frame_allocator.rs
View File

@ -16,13 +16,7 @@ pub struct AreaFrameAllocator {
}
impl AreaFrameAllocator {
pub fn new(
kernel_start: u64,
kernel_end: u64,
multiboot_start: u64,
multiboot_end: u64,
memory_areas: MemoryAreaIter,
) -> AreaFrameAllocator {
pub fn new(kernel_start: u64, kernel_end: u64, multiboot_start: u64, multiboot_end: u64, memory_areas: MemoryAreaIter) -> AreaFrameAllocator {
let mut allocator = AreaFrameAllocator {
next_free_frame: Frame::containing_address(PhysAddr::new(0)),
current_area: None,
@ -103,8 +97,7 @@ pub struct TinyAllocator([Option<Frame>; 3]);
impl TinyAllocator {
pub fn new<A>(allocator: &mut A) -> TinyAllocator
where
A: FrameAllocator<Size4KiB>,
where A: FrameAllocator<Size4KiB>
{
let mut f = || allocator.allocate_frame();
let frames = [f(), f(), f()];

140
src/memory/paging/mod.rs
View File

@ -1,114 +1,64 @@
use super::PAGE_SIZE;
use multiboot2::BootInformation;
pub use x86_64::structures::paging::{FrameAllocator, Size4KiB, PageTable, RecursivePageTable, Page, PageTableFlags as Flags, Mapper, PhysFrame as Frame};
use crate::println;
use multiboot2::{BootInformation, ElfSection};
use temporary_page::TemporaryPage;
use x86_64::{VirtAddr, PhysAddr};
use x86_64::registers::control;
pub use x86_64::structures::paging::{
FrameAllocator, Mapper, Page, PageTable, PageTableFlags as Flags, PhysFrame as Frame,
RecursivePageTable, Size4KiB,
};
use x86_64::{PhysAddr, VirtAddr};
use temporary_page::TemporaryPage;
use super::PAGE_SIZE;
mod temporary_page;
pub const P4: *mut PageTable = 0o177777_777_777_777_777_0000 as *mut _;
fn get_flags_from_elf_section(section: &ElfSection) -> Flags {
use multiboot2::{ELF_SECTION_ALLOCATED, ELF_SECTION_EXECUTABLE, ELF_SECTION_WRITABLE};
let mut flags = Flags::empty();
if section.flags().contains(ELF_SECTION_ALLOCATED) {
flags = flags | Flags::PRESENT;
}
if section.flags().contains(ELF_SECTION_WRITABLE) {
flags = flags | Flags::WRITABLE;
}
if !section.flags().contains(ELF_SECTION_EXECUTABLE) {
flags = flags | Flags::NO_EXECUTE;
}
flags
}
pub fn kernel_remap<A>(allocator: &mut A, boot_info: &BootInformation)
where
A: FrameAllocator<Size4KiB>,
where A: FrameAllocator<Size4KiB>
{
println!("Remapping kernel");
let mut temporary_page = TemporaryPage::new(
Page::containing_address(VirtAddr::new(0xcafebabe)),
allocator,
);
let mut temporary_page = TemporaryPage::new(Page::containing_address(VirtAddr::new(0xcafebabe)), allocator);
let mut active_table = get_active_page_table();
let mut new_table = {
let frame = allocator.allocate_frame().expect("No more frames");
InactivePageTable::new(frame, &mut active_table, &mut temporary_page)
};
new_table.under(&mut active_table, &mut temporary_page, |mapper| {
let elf_sections_tag = boot_info
.elf_sections_tag()
.expect("Elf sections tag required");
let elf_sections_tag = boot_info.elf_sections_tag().expect("Elf sections tag required");
for section in elf_sections_tag.sections() {
if !section.is_allocated() {
// section is not loaded to memory
continue;
}
assert!(
section.start_address() % PAGE_SIZE == 0,
"sections need to be page aligned"
);
println!("mapping section at addr: {:#x}, size: {:#x}",
section.addr, section.size);
assert!(section.start_address() % PAGE_SIZE == 0,
"sections need to be page aligned");
let flags = get_flags_from_elf_section(section);
let start_frame = Frame::<Size4KiB>::containing_address(PhysAddr::new(
section.start_address() as u64,
));
let end_frame =
Frame::containing_address(PhysAddr::new(section.end_address() as u64 - 1));
let flags = Flags::WRITABLE | Flags::PRESENT;
let start_frame = Frame::<Size4KiB>::containing_address(PhysAddr::new(section.start_address() as u64));
let end_frame = Frame::containing_address(PhysAddr::new(section.end_address() as u64 - 1));
for frame in Frame::range_inclusive(start_frame, end_frame) {
unsafe {
mapper
.identity_map(frame, flags, allocator)
.expect("Failed to identity map kernel")
.flush();
mapper.identity_map(frame, flags, allocator).expect("Failed to identity map kernel").flush();
}
}
}
let vga_buffer_frame = Frame::<Size4KiB>::containing_address(PhysAddr::new(0xb8000));
unsafe {
mapper
.identity_map(
vga_buffer_frame,
Flags::PRESENT | Flags::WRITABLE,
allocator,
)
.expect("Failed to identity map VGA buffer")
.flush();
mapper.identity_map(vga_buffer_frame, Flags::PRESENT | Flags::WRITABLE, allocator).expect("Failed to identity map VGA buffer").flush();
}
let multiboot_start =
Frame::<Size4KiB>::containing_address(PhysAddr::new(boot_info.start_address() as u64));
let multiboot_end =
Frame::containing_address(PhysAddr::new(boot_info.end_address() as u64 - 1));
let multiboot_start = Frame::<Size4KiB>::containing_address(PhysAddr::new(boot_info.start_address() as u64));
let multiboot_end = Frame::containing_address(PhysAddr::new(boot_info.end_address() as u64 - 1));
for frame in Frame::range_inclusive(multiboot_start, multiboot_end) {
unsafe {
mapper
.identity_map(frame, Flags::PRESENT, allocator)
.expect("Failed to identity map multiboot info struct")
.flush();
mapper.identity_map(frame, Flags::PRESENT, allocator).expect("Failed to identity map multiboot info struct").flush();
}
}
});
let old_table = new_table.activate();
new_table.activate();
println!("Loaded new page table!");
let old_p4_page = Page::<Size4KiB>::containing_address(VirtAddr::new(
old_table.p4_frame.start_address().as_u64(),
));
active_table.unmap(old_p4_page).expect("Failed to unmap old P4").1.flush();
println!("Stack guard page at {:#x}", old_p4_page.start_address());
}
struct InactivePageTable {
@ -116,11 +66,8 @@ struct InactivePageTable {
}
impl InactivePageTable {
pub fn new(
frame: Frame,
active_table: &mut RecursivePageTable,
temporary_page: &mut TemporaryPage,
) -> InactivePageTable {
pub fn new(frame: Frame, active_table: & mut RecursivePageTable,
temporary_page: &mut TemporaryPage) -> InactivePageTable {
let table = temporary_page.map_table_frame(frame, active_table);
table.zero();
table[511].set_frame(frame.clone(), Flags::PRESENT | Flags::WRITABLE);
@ -128,13 +75,9 @@ impl InactivePageTable {
InactivePageTable { p4_frame: frame }
}
pub fn under<F>(
&mut self,
active_table: &mut RecursivePageTable,
temporary_page: &mut TemporaryPage,
f: F,
) where
F: FnOnce(&mut RecursivePageTable),
pub fn under<F>(&mut self, active_table: &mut RecursivePageTable,
temporary_page: &mut TemporaryPage, f: F)
where F: FnOnce(&mut RecursivePageTable)
{
let backup = control::Cr3::read().0;
let p4_table = temporary_page.map_table_frame(backup, active_table);
@ -153,7 +96,9 @@ impl InactivePageTable {
pub fn activate(&mut self) -> InactivePageTable {
let old_table = InactivePageTable {
p4_frame: Frame::containing_address(control::Cr3::read().0.start_address()),
p4_frame: Frame::containing_address(
control::Cr3::read().0.start_address()
),
};
unsafe {
control::Cr3::write(self.p4_frame, control::Cr3Flags::empty());
@ -163,5 +108,28 @@ impl InactivePageTable {
}
pub fn get_active_page_table() -> RecursivePageTable<'static> {
unsafe { RecursivePageTable::new(&mut *P4).expect("Could not create Page Table") }
unsafe {
RecursivePageTable::new(&mut *P4).expect("Could not create Page Table")
}
}
pub fn test_paging<A>(allocator: &mut A)
where A: FrameAllocator<Size4KiB>
{
let mut page_table = get_active_page_table();
let addr = 42 * 512 * 512 * 4096; // 42th P3 entry
let page = Page::containing_address(VirtAddr::new(addr));
let frame = allocator.allocate_frame().expect("no more frames");
println!("None = , map to {:?}", frame);
unsafe { page_table.map_to(page, frame, Flags::PRESENT, allocator).expect("Could not map").flush() };
println!("next free frame: {:?}", allocator.allocate_frame());
let page_ptr: *mut u8 = page.start_address().as_mut_ptr();
let frame_ptr: *mut u8 = frame.start_address().as_u64() as *mut u8;
unsafe {
println!("Page: {:#?}, Frame: {:#?}", page_ptr, frame_ptr);
}
}

30
src/memory/paging/temporary_page.rs
View File

@ -1,7 +1,5 @@
use super::{Page, Flags, VirtAddr, RecursivePageTable, Mapper, FrameAllocator, Size4KiB, Frame, PageTable};
use super::super::frame_allocator::TinyAllocator;
use super::{
Flags, Frame, FrameAllocator, Mapper, Page, PageTable, RecursivePageTable, Size4KiB, VirtAddr,
};
pub struct TemporaryPage {
page: Page,
@ -10,8 +8,7 @@ pub struct TemporaryPage {
impl TemporaryPage {
pub fn new<A>(page: Page, allocator: &mut A) -> TemporaryPage
where
A: FrameAllocator<Size4KiB>,
where A: FrameAllocator<Size4KiB>
{
TemporaryPage {
page,
@ -21,32 +18,17 @@ impl TemporaryPage {
pub fn map(&mut self, frame: Frame, active_table: &mut RecursivePageTable) -> VirtAddr {
unsafe {
active_table
.map_to(
self.page,
frame,
Flags::PRESENT | Flags::WRITABLE,
&mut self.allocator,
)
.expect("Failed to map temporary page")
.flush();
active_table.map_to(self.page, frame, Flags::PRESENT | Flags::WRITABLE, &mut self.allocator).expect("Failed to map temporary page").flush();
}
self.page.start_address()
}
pub fn unmap(&mut self, active_table: &mut RecursivePageTable) {
active_table
.unmap(self.page)
.expect("Failed to unmap")
.1
.flush()
active_table.unmap(self.page).expect("Failed to unmap").1.flush()
}
pub fn map_table_frame(
&mut self,
frame: Frame,
active_table: &mut RecursivePageTable,
) -> &mut PageTable {
pub fn map_table_frame(&mut self, frame: Frame,
active_table: &mut RecursivePageTable) -> &mut PageTable {
unsafe { &mut *(self.map(frame, active_table).as_u64() as *mut PageTable) }
}
}