Jump to kernel

kernel/.cargo/config.toml

@@ -1,3 +1,3 @@
 [build]
 target = "x86_64-unknown-none"
-rustflags = ["-C", "link-arg=link.ld"]
+rustflags = ["-C", "link-arg=link.ld", "-C", "link-arg=-no-pie"]

kernel/Cargo.lock

@@ -2,6 +2,74 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "bit_field"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc827186963e592360843fb5ba4b973e145841266c1357f7180c43526f2e5b61"
+
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "com_logger"
+version = "0.1.1"
+source = "git+https://git.strypsteen.com/mathieu/com_logger#2dc5c9d0fd04e3e9102f0dbed25187761cf07525"
+dependencies = [
+ "log",
+ "uart_16550",
+]
+
 [[package]]
 name = "kernel"
 version = "0.0.1"
+dependencies = [
+ "com_logger",
+ "log",
+]
+
+[[package]]
+name = "log"
+version = "0.4.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
+
+[[package]]
+name = "raw-cpuid"
+version = "10.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c297679cb867470fa8c9f67dbba74a78d78e3e98d7cf2b08d6d71540f797332"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "rustversion"
+version = "1.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "955d28af4278de8121b7ebeb796b6a45735dc01436d898801014aced2773a3d6"
+
+[[package]]
+name = "uart_16550"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6dc00444796f6c71f47c85397a35e9c4dbf9901902ac02386940d178e2b78687"
+dependencies = [
+ "bitflags",
+ "rustversion",
+ "x86",
+]
+
+[[package]]
+name = "x86"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2781db97787217ad2a2845c396a5efe286f87467a5810836db6d74926e94a385"
+dependencies = [
+ "bit_field",
+ "bitflags",
+ "raw-cpuid",
+]

kernel/Cargo.toml

@@ -4,3 +4,5 @@ version = "0.0.1"
 edition = "2021"
 
 [dependencies]
+com_logger = { git = "https://git.strypsteen.com/mathieu/com_logger", version = "0.1.1" }
+log = "0.4.22"

kernel/src/main.rs

@@ -1,14 +1,26 @@
 #![no_std]
 #![no_main]
 
-use core::panic::PanicInfo;
+use core::{arch::asm, panic::PanicInfo};
+
+use log::{error, info};
+
+static mut STACK: [u8; 8 * 1024] = [0; 8 * 1024];
 
 #[no_mangle]
-fn _start() {
+fn _start() -> ! {
+    unsafe {
+        asm!("mov rsp, {}", in(reg) STACK.as_ptr().add(STACK.len()));
+    }
+    main();
+}
+fn main() -> ! {
+    com_logger::init();
+    info!("Starting kernel...");
     loop {}
 }
-
 #[panic_handler]
-fn panic(_info: &PanicInfo) -> ! {
+fn panic(info: &PanicInfo) -> ! {
+    error!("{}", info);
     loop {}
 }

loader/src/elf.rs

@@ -6,9 +6,9 @@ use uefi::table::{
     Boot, SystemTable,
 };
 
-const KERNEL_VIRT_START: u64 = 0xffffffff80000000;
+pub const KERNEL_VIRT_START: u64 = 0xffffffff80000000;
 
-pub fn load_kernel(kernel: &[u8], system_table: &SystemTable<Boot>) {
+pub fn load_kernel(kernel: &[u8], system_table: &SystemTable<Boot>) -> (u64, usize, u64) {
     let file: ElfBytes<LittleEndian> = ElfBytes::minimal_parse(kernel).unwrap();
     let mut kernel_size = 0;
     for i in file.segments().unwrap() {
@@ -37,4 +37,5 @@ pub fn load_kernel(kernel: &[u8], system_table: &SystemTable<Boot>) {
             ptr::copy(kernel[i.p_offset.try_into().unwrap()..].as_ptr(), start_addr as *mut u8, i.p_filesz.try_into().unwrap());
         }
     }
+    (phys_start, kernel_size as usize, file.ehdr.e_entry)
 }

loader/src/main.rs

@@ -3,7 +3,7 @@
 
 extern crate alloc;
 
-use core::panic::PanicInfo;
+use core::{mem, panic::PanicInfo};
 
 use elf::load_kernel;
 use log::{error, info};
@@ -28,9 +28,13 @@ fn main(image_handle: Handle, mut system_table: SystemTable<Boot>) -> Status {
     com_logger::init();
     info!("Starting bootloader...");
     uefi::helpers::init(&mut system_table).unwrap();
-    load_kernel(KERNEL, &system_table);
+    let (kernel_start, kernel_size, kernel_entry) = load_kernel(KERNEL, &system_table);
     let memory_map = system_table.exit_boot_services(MemoryType::LOADER_DATA).1;
-    setup_paging(&memory_map);
+    setup_paging(&memory_map, kernel_start, kernel_size);
+    info!("Jumping to kernel...");
+    unsafe {
+        (mem::transmute::<_, fn()>(kernel_entry))();
+    }
     loop {}
 }
 #[panic_handler]

loader/src/paging.rs

@@ -8,6 +8,8 @@ use x86_64::{
     PhysAddr,
 };
 
+use crate::elf;
+
 fn get_table_entry(table: &mut PageTable, i: usize) -> &mut PageTable {
     if table[i].is_unused() {
         let layout = Layout::new::<PageTable>().align_to(0x1000).unwrap();
@@ -35,7 +37,7 @@ fn map(pml4: &mut PageTable, mut virt: usize, phys: usize) {
     let phys_addr = PhysAddr::new(phys as u64);
     table[table_i].set_addr(phys_addr, PageTableFlags::PRESENT | PageTableFlags::WRITABLE)
 }
-pub fn setup_paging(memory_map: &MemoryMap) {
+pub fn setup_paging(memory_map: &MemoryMap, kernel_start: u64, kernel_size: usize) {
     let pml4;
     let layout = Layout::new::<PageTable>().align_to(0x1000).unwrap();
     unsafe {
@@ -55,6 +57,11 @@ pub fn setup_paging(memory_map: &MemoryMap) {
             }
         }
     }
+    for i in 0..((kernel_size + 0xfff) / 0x1000) {
+        let virt = elf::KERNEL_VIRT_START as usize + i * 0x1000;
+        let phys = kernel_start as usize + i * 0x1000;
+        map(pml4, virt, phys);
+    }
     let pml4_addr = PhysAddr::new(pml4 as *const PageTable as u64);
     let frame = PhysFrame::from_start_address(pml4_addr).unwrap();
     unsafe {