wip

Author: phil-opp

build.rs

@@ -9,12 +9,10 @@ fn main() {
     cmd.arg("--manifest-path").arg("protected_mode/Cargo.toml");
     cmd.arg("--target").arg("protected_mode/i686-bootloader.json");
     cmd.env("RUSTFLAGS", "");
-    cmd.status().unwrap();
+    assert!(cmd.status().unwrap().success());
 
     let out_dir = Path::new("protected_mode/target/i686-bootloader/release").canonicalize().unwrap();
 
-    println!("cargo:rustc-link-search=native={}", out_dir.display());
-    println!("cargo:rustc-link-lib=static=protected_mode");
-
-    println!("cargo:rerun-if-changed=protected_mode");
+    println!("cargo:rerun-if-changed=protected_mode/*");
+    println!("cargo:rerun-if-changed=protected_mode/**/*");
 }

linker.ld

@@ -1,4 +1,4 @@
-ENTRY(entry_point)
+ENTRY(first_stage)
 
 SECTIONS {
     . = 0x500;

protected_mode/Cargo.lock

@@ -8,4 +8,4 @@ edition = "2018"
 crate-type = ["staticlib"]
 
 [dependencies]
-x86_64 = "0.3"
+x86_64 = "0.3.3"

protected_mode/Cargo.toml

@@ -3,29 +3,20 @@
 
 #![no_std]
 
-use core::panic::PanicInfo;
-
 global_asm!(include_str!("e820.s"));
 
 pub mod stages;
+mod printer;
 
-extern "C" {
-    pub fn first_stage();
-}
-
-#[no_mangle]
-pub extern "C" fn hello_world() {
-    unsafe { first_stage() }
-}
+use core::panic::PanicInfo;
 
 #[panic_handler]
-#[no_mangle]
-pub extern "C" fn panic(_info: &PanicInfo) -> ! {
+extern "C" fn panic(_info: &PanicInfo) -> ! {
     loop {}
 }
 
 #[lang = "eh_personality"]
 #[no_mangle]
-pub extern "C" fn eh_personality() {
+extern "C" fn eh_personality() {
     loop {}
 }

protected_mode/src/lib.rs

@@ -51,7 +51,7 @@ load_bootloader_rest_from_disk:
     mov [dap_blocks], bx
 
     # number of start block
-    lea ebx, _start
+    lea ebx, first_stage
     sub eax, ebx
     shr eax, 9 # divide by 512 (block size)
     mov [dap_start_lba], eax

protected_mode/src/stages/stage_1.s

@@ -33,7 +33,7 @@ load_kernel_from_disk:
 
     # number of start block
     lea eax, _kernel_start_addr
-    lea ebx, _start
+    lea ebx, first_stage
     sub eax, ebx
     shr eax, 9 # divide by 512 (block size)
     mov [dap_start_lba], eax

protected_mode/src/stages/stage_2.s

@@ -1,8 +1,46 @@
+use x86_64::{
+    ux::u9,
+    PhysAddr,
+    structures::paging::{PageTable, PageTableFlags, PhysFrame, Size2MiB},
+};
+
+
+extern {
+    static mut _p4: PageTable;
+    static mut _p3: PageTable;
+    static mut _p2: PageTable;
+}
+
 #[no_mangle]
 extern "C" fn stage_3() -> ! {
+    // Identity mapping of first gigabyte + recursive mapping of P4 table
+    /*unsafe {
+        let p4_addr = PhysAddr::new(&P4 as *const PageTable as u64);
+        let p3_addr = PhysAddr::new(&P3 as *const PageTable as u64);
+        let p2_addr = PhysAddr::new(&P2 as *const PageTable as u64);
+
+        P4[0].set_addr(p3_addr, PageTableFlags::PRESENT | PageTableFlags::WRITABLE);
+        P4[511].set_addr(p4_addr, PageTableFlags::PRESENT | PageTableFlags::WRITABLE);
+        P3[0].set_addr(p2_addr, PageTableFlags::PRESENT | PageTableFlags::WRITABLE);
+        {
+            let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE | PageTableFlags::HUGE_PAGE;
+            let start_frame = PhysFrame::<Size2MiB>::containing_address(PhysAddr::new(0));
+            for i in 0u16..512 {
+                P2[u9::new(i)].set_addr((start_frame + i.into()).start_address(), flags);
+            }
+        }
+    }
+    */
+
+    use core::fmt::Write;
+    unsafe {
+    write!(crate::printer::Printer, "P4: {}, P3: {}, P2 {}", &_p4 as *const _ as u32, &_p3 as *const _ as u32, &_p2 as *const _ as u32);
+    }
+
     let ptr = 0xb8200 as *mut u16;
     unsafe {
         *ptr = 0xffff;
     }
     loop {}
 }
+

protected_mode/src/stages/stage_3.rs

@@ -1,18 +1,26 @@
+#![feature(lang_items)]
+
 #![no_std]
 #![no_main]
 
 use core::panic::PanicInfo;
 
 extern "C" {
-    fn hello_world();
+    fn first_stage();
 }
 
 #[no_mangle]
-pub extern "C" fn entry_point() {
-    unsafe {hello_world();}
+pub extern "C" fn ensure_that_first_stage_is_callable() {
+    unsafe {first_stage();}
 }
 
 #[panic_handler]
-extern "C" fn panic(info: &PanicInfo) -> ! {
+extern "C" fn panic(_info: &PanicInfo) -> ! {
+    loop {}
+}
+
+#[lang = "eh_personality"]
+#[no_mangle]
+pub extern "C" fn eh_personality() {
     loop {}
 }

src/main.rs

@@ -9,6 +9,11 @@
 	        "--script=linker.ld"
 	    ]
     },
+    "post-link-args": {
+        "ld.lld": [
+	        "protected_mode/target/i686-bootloader/release/libprotected_mode.rlib"
+	    ]
+    },
     "target-endian": "little",
     "target-pointer-width": "32",
     "target-c-int-width": "32",