diff --git a/src/lib.rs b/src/lib.rs index f86b0ac..8c0d516 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -24,37 +24,23 @@ mod vga_buffer; mod memory; #[no_mangle] -pub extern fn rust_main(multiboot_information_address: usize) { - use memory::FrameAllocator; - +pub extern "C" fn rust_main(multiboot_information_address: usize) { + // ATTENTION: we have a very small stack and no guard page vga_buffer::clear_screen(); println!("Hello World{}", "!"); - let boot_info = unsafe{ multiboot2::load(multiboot_information_address) }; - let memory_map_tag = boot_info.memory_map_tag() - .expect("Memory map tag required"); - let elf_sections_tag = boot_info.elf_sections_tag() - .expect("Elf sections tag required"); - - let kernel_start = elf_sections_tag.sections().map(|s| s.addr) - .min().unwrap(); - let kernel_end = elf_sections_tag.sections().map(|s| s.addr + s.size) - .max().unwrap(); - let multiboot_start = multiboot_information_address; - let multiboot_end = multiboot_start + (boot_info.total_size as usize); + let boot_info = unsafe { + multiboot2::load(multiboot_information_address) + }; + enable_nxe_bit(); + enable_write_protect_bit(); - println!("kernel start: 0x{:x}, kernel end: 0x{:x}", - kernel_start, kernel_end); - println!("multiboot start: 0x{:x}, multiboot end: 0x{:x}", - multiboot_start, multiboot_end); + // set up guard page and map the heap pages + memory::init(boot_info); - let mut frame_allocator = memory::AreaFrameAllocator::new( - kernel_start as usize, kernel_end as usize, multiboot_start, - multiboot_end, memory_map_tag.memory_areas()); + use alloc::boxed::Box; + let heap_test = Box::new(42); - enable_nxe_bit(); - enable_write_protect_bit(); - memory::remap_the_kernel(&mut frame_allocator, boot_info); println!("It did not crash!"); loop {} diff --git a/src/memory/mod.rs b/src/memory/mod.rs index a2f071c..848a105 100644 --- a/src/memory/mod.rs +++ b/src/memory/mod.rs @@ -1,6 +1,7 @@ pub use self::area_frame_allocator::AreaFrameAllocator; pub use self::paging::remap_the_kernel; use self::paging::PhysicalAddress; +use multiboot2::BootInformation; mod area_frame_allocator; pub mod heap_allocator; @@ -8,6 +9,34 @@ mod paging; pub const PAGE_SIZE: usize = 4096; + +pub fn init(boot_info: &BootInformation) { + let memory_map_tag = boot_info.memory_map_tag().expect( + "Memory map tag required"); + let elf_sections_tag = boot_info.elf_sections_tag().expect( + "Elf sections tag required"); + + let kernel_start = elf_sections_tag.sections() + .filter(|s| s.is_allocated()).map(|s| s.addr).min().unwrap(); + let kernel_end = elf_sections_tag.sections() + .filter(|s| s.is_allocated()).map(|s| s.addr + s.size).max() + .unwrap(); + + println!("kernel start: {:#x}, kernel end: {:#x}", + kernel_start, + kernel_end); + println!("multiboot start: {:#x}, multiboot end: {:#x}", + boot_info.start_address(), + boot_info.end_address()); + + let mut frame_allocator = AreaFrameAllocator::new( + kernel_start as usize, kernel_end as usize, + boot_info.start_address(), boot_info.end_address(), + memory_map_tag.memory_areas()); + + paging::remap_the_kernel(&mut frame_allocator, boot_info); +} + #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)] pub struct Frame { number: usize,