commit 2c423554f64670ebfc0a93c7e8261014ea4088b2 Author: Evie Viau Date: Mon Jun 30 20:13:23 2025 -0700 init diff --git a/.cargo/config.toml b/.cargo/config.toml new file mode 100644 index 0000000..622eca8 --- /dev/null +++ b/.cargo/config.toml @@ -0,0 +1,2 @@ +[build] +target = "x86_64-unknown-none" \ No newline at end of file diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..f320c71 --- /dev/null +++ b/.gitignore @@ -0,0 +1,14 @@ +# Generated by Cargo +# will have compiled files and executables +**/debug +**/target + +# These are backup files generated by rustfmt +**/*.rs.bk + +# MSVC Windows builds of rustc generate these, which store debugging information +*.pdb + +# Generated by cargo mutants +# Contains mutation testing data +**/mutants.out*/ \ No newline at end of file diff --git a/Cargo.lock b/Cargo.lock new file mode 100644 index 0000000..d9aafe9 --- /dev/null +++ b/Cargo.lock @@ -0,0 +1,190 @@ +# This file is automatically @generated by Cargo. +# It is 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"atomalloc", + "elf", + "hashbrown", + "libgoatweed", + "limine", + "linked_list_allocator", + "spin", + "tar-no-std", + "x86_64", +] + +[[package]] +name = "libgoatweed" +version = "0.1.0" +source = "git+https://forge.gaycatgirl.sex/hypericum/libgoatweed.git?rev=31ac8671a3cfb338ae66957c963a9ced72fa2251#31ac8671a3cfb338ae66957c963a9ced72fa2251" + +[[package]] +name = "limine" +version = "0.5.0" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "af6d2ee42712e7bd2c787365cd1dab06ef59a61becbf87bec7b32b970bd2594b" +dependencies = [ + "bitflags", +] + +[[package]] +name = "linked_list_allocator" +version = "0.10.5" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "9afa463f5405ee81cdb9cc2baf37e08ec7e4c8209442b5d72c04cfb2cd6e6286" +dependencies = [ + "spinning_top", +] + +[[package]] +name = "lock_api" +version = "0.4.13" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = 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"registry+https://github.com/rust-lang/crates.io-index" +checksum = "442887c63f2c839b346c192d047a7c87e73d0689c9157b00b53dcc27dd5ea793" + +[[package]] +name = "x86_64" +version = "0.15.2" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "0f042214de98141e9c8706e8192b73f56494087cc55ebec28ce10f26c5c364ae" +dependencies = [ + "bit_field", + "bitflags", + "rustversion", + "volatile", +] diff --git a/Cargo.toml b/Cargo.toml new file mode 100644 index 0000000..b9fa3dd --- /dev/null +++ b/Cargo.toml @@ -0,0 +1,34 @@ +[package] +name = "kernel" +version = "0.1.0" +edition = "2024" +license = "GPL-2.0-only" + +[dependencies] +libgoatweed = { git = "https://forge.gaycatgirl.sex/hypericum/libgoatweed.git", rev = "31ac8671a3cfb338ae66957c963a9ced72fa2251" , default-features = false } +atomalloc = { git = "https://forge.gaycatgirl.sex/hypericum/atomalloc.git", rev = "6f6687429e5e89c16e813dbeab4af30e05e2e8a2", default-features = false, features = ["no_alloc"] } + +# bootloader info structs +limine = "0.5.0" + +# sync prims +spin = "0.10.0" + +# some niceities +x86_64 = "0.15.2" + +# alloc +linked_list_allocator = "0.10.5" + +# stuff for init +tar-no-std = { version = "0.3.3", features = ["alloc", "unstable"] } +elf = { version = "0.7.4", default-features = false, features = [] } + +# hashmaps and hashsets +hashbrown = "0.15.2" + +[[bin]] +name = "kernel" +test = false +doctest = false +bench = false \ No newline at end of file diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..ecbc059 --- /dev/null +++ b/LICENSE @@ -0,0 +1,339 @@ + GNU GENERAL PUBLIC LICENSE + Version 2, June 1991 + + Copyright (C) 1989, 1991 Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. 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You may copy and distribute verbatim copies of the Program's +source code as you receive it, in any medium, provided that you +conspicuously and appropriately publish on each copy an appropriate +copyright notice and disclaimer of warranty; keep intact all the +notices that refer to this License and to the absence of any warranty; +and give any other recipients of the Program a copy of this License +along with the Program. + +You may charge a fee for the physical act of transferring a copy, and +you may at your option offer warranty protection in exchange for a fee. + + 2. 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IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR +REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, +INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING +OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED +TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY +YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER +PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE +POSSIBILITY OF SUCH DAMAGES. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +convey the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +Also add information on how to contact you by electronic and paper mail. + +If the program is interactive, make it output a short notice like this +when it starts in an interactive mode: + + Gnomovision version 69, Copyright (C) year name of author + Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, the commands you use may +be called something other than `show w' and `show c'; they could even be +mouse-clicks or menu items--whatever suits your program. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a "copyright disclaimer" for the program, if +necessary. Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the program + `Gnomovision' (which makes passes at compilers) written by James Hacker. + + , 1 April 1989 + Ty Coon, President of Vice + +This General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may +consider it more useful to permit linking proprietary applications with the +library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. \ No newline at end of file diff --git a/README.md b/README.md new file mode 100644 index 0000000..e69de29 diff --git a/build.rs b/build.rs new file mode 100644 index 0000000..dd9d377 --- /dev/null +++ b/build.rs @@ -0,0 +1,4 @@ +fn main() { + println!("cargo:rustc-link-arg=-Tlinkers/x86_64.ld"); + println!("cargo:rerun-if-changed=linkers/x86_64.ld"); +} \ No newline at end of file diff --git a/linkers/x86_64.ld b/linkers/x86_64.ld new file mode 100644 index 0000000..3d50b2c --- /dev/null +++ b/linkers/x86_64.ld @@ -0,0 +1,72 @@ +/* Tell the linker that we want an x86_64 ELF64 output file */ +OUTPUT_FORMAT(elf64-x86-64) +OUTPUT_ARCH(i386:x86-64) + +/* We want the symbol _kmain to be our entry point */ +ENTRY(_kmain) + +/* Define the program headers we want so the bootloader gives us the right */ +/* MMU permissions */ +PHDRS +{ + text PT_LOAD FLAGS(0x05); /* Execute + Read */ + rodata PT_LOAD FLAGS(0x04); /* Read only */ + data PT_LOAD FLAGS(0x06); /* Write + Read */ + dynamic PT_DYNAMIC FLAGS(0x06); /* Dynamic PHDR for relocations */ +} + +SECTIONS +{ + /* We wanna be placed in the topmost 2GiB of the address space, for optimisations */ + /* Any address in this region will do, but often 0xffffffff80000000 is chosen as */ + /* that is the beginning of the region. */ + . = 0xffffffff80000000; + + .text : { + *(.text .text.*) + } :text + + /* Move to the next memory page for .rodata */ + . = ALIGN(CONSTANT(MAXPAGESIZE)); + + .rodata : { + *(.rodata .rodata.*) + } :rodata + + /* Move to the next memory page for .data */ + . = ALIGN(CONSTANT(MAXPAGESIZE)); + + .data : { + *(.data .data.*) + + /* Place the sections that contain the requests as part of the .data */ + /* output section. */ + KEEP(*(.requests_start_marker)) + KEEP(*(.requests)) + KEEP(*(.requests_end_marker)) + } :data + + /* Dynamic section for relocations, both in its own PHDR and inside data PHDR */ + .dynamic : { + *(.dynamic) + } :data :dynamic + + /* NOTE: .bss needs to be the last thing mapped to :data, otherwise lots of */ + /* unnecessary zeros will be written to the binary. */ + /* If you need, for example, .init_array and .fini_array, those should be placed */ + /* above this. */ + .bss : { + *(.bss .bss.*) + *(COMMON) + } :data + + /* Discard .note.* and .eh_frame* since they may cause issues on some hosts. */ + /* Also discard the program interpreter section since we do not need one. This is */ + /* more or less equivalent to the --no-dynamic-linker linker flag, except that it */ + /* works with ld.gold. */ + /DISCARD/ : { + *(.eh_frame*) + *(.note .note.*) + *(.interp) + } +} diff --git a/rust-toolchain.toml b/rust-toolchain.toml new file mode 100644 index 0000000..271800c --- /dev/null +++ b/rust-toolchain.toml @@ -0,0 +1,2 @@ +[toolchain] +channel = "nightly" \ No newline at end of file diff --git a/src/arch/amd64/devices/i8259.rs b/src/arch/amd64/devices/i8259.rs new file mode 100644 index 0000000..e3204f3 --- /dev/null +++ b/src/arch/amd64/devices/i8259.rs @@ -0,0 +1,147 @@ +use spin::Mutex; +use crate::arch::amd64::port::Port; +use crate::println; +use crate::print; + +pub const PIC_1_OFFSET: u8 = 32; +pub const PIC_2_OFFSET: u8 = PIC_1_OFFSET + 8; + +pub static PICS: Mutex = Mutex::new(unsafe { + PicPair::new(PIC_1_OFFSET, PIC_2_OFFSET) +}); + +pub struct Pic { + offset: u8, + pub(crate) command: Port, + pub(crate) data: Port, +} + +impl Pic { + fn handles_interrupt(&self, interrupt: u8) -> bool { + self.offset <= interrupt && interrupt <= self.offset + 8 + } + + unsafe fn end_interrupt(&mut self) { + unsafe { + self.command.write_u8(0x20u8); + } + } + + unsafe fn read_interrupt_mask(&mut self) -> u8 { + unsafe { + self.data.read_u8() + } + } + + unsafe fn write_interrupt_mask(&mut self, mask: u8) { + unsafe { + self.data.write_u8(mask); + } + } +} + +pub struct PicPair { + pub(crate) pics: [Pic; 2], +} + +impl PicPair { + pub const unsafe fn new(offset_one: u8, offset_two: u8) -> Self { + PicPair { + pics: [ + Pic { + offset: offset_one, + command: Port::new(0x20), + data: Port::new(0x21), + }, + Pic { + offset: offset_two, + command: Port::new(0xA0), + data: Port::new(0xA1), + } + ], + } + } + + pub unsafe fn init(&mut self) { + let mut wait_port = Port::new(0x80); + + unsafe { + let mut wait = || wait_port.write_u8(0); + + let mut saved_masks = self.read_masks(); + + // init command + self.pics[0].command.write_u8(0x11u8); + wait(); + self.pics[1].command.write_u8(0x11u8); + wait(); + + // set offsets + self.pics[0].data.write_u8(self.pics[0].offset); + wait(); + self.pics[1].data.write_u8(self.pics[1].offset); + wait(); + + // pair the pics together + self.pics[0].data.write_u8(4); + wait(); + self.pics[1].data.write_u8(2); + wait(); + + // set the response mode + self.pics[0].data.write_u8(0x01u8); + wait(); + self.pics[1].data.write_u8(0x01u8); + wait(); + + // Mask all interrupts initially + saved_masks[0] = 255; + saved_masks[1] = 255; + + // Enable timer + saved_masks[0] &= !1; + + // Enable keyboard + // saved_masks[0] &= !2; + + self.write_masks(saved_masks[0], saved_masks[1]); + } + } + + pub unsafe fn read_masks(&mut self) -> [u8; 2] { + unsafe { + [self.pics[0].read_interrupt_mask(), self.pics[1].read_interrupt_mask()] + } + } + + pub unsafe fn write_masks(&mut self, mask_one: u8, mask_two: u8) { + unsafe { + self.pics[0].write_interrupt_mask(mask_one); + self.pics[1].write_interrupt_mask(mask_two); + } + } + + pub unsafe fn disable(&mut self) { + unsafe { + self.write_masks(u8::MAX, u8::MAX); + } + } + + pub unsafe fn handles_interrupt(&mut self, interrupt: u8) -> bool { + self.pics.iter().any(|p| p.handles_interrupt(interrupt)) + } + + pub unsafe fn notify_end_interrupt(&mut self, interrupt: u8) { + unsafe { + if self.handles_interrupt(interrupt) { + if self.pics[1].handles_interrupt(interrupt) { + self.pics[1].end_interrupt(); + } + + self.pics[0].end_interrupt(); + } else { + println!("? eoi called for a non-pic interrupt") + } + } + } +} \ No newline at end of file diff --git a/src/arch/amd64/devices/mod.rs b/src/arch/amd64/devices/mod.rs new file mode 100644 index 0000000..dea1cec --- /dev/null +++ b/src/arch/amd64/devices/mod.rs @@ -0,0 +1,3 @@ +pub mod i8259; +#[macro_use] +pub mod serial; \ No newline at end of file diff --git a/src/arch/amd64/devices/serial.rs b/src/arch/amd64/devices/serial.rs new file mode 100644 index 0000000..077fb16 --- /dev/null +++ b/src/arch/amd64/devices/serial.rs @@ -0,0 +1,92 @@ +use spin::lazy::Lazy; +use spin::mutex::Mutex; +use crate::arch::amd64::instructions::{inb, outb}; + +// pub static SERIAL_WRITER: Lazy> = Lazy::new(|| { +// Mutex::new(SerialWriter::new(SerialPort::COM1)) +// }); + +#[derive(Copy, Clone)] +#[repr(u16)] +pub enum SerialPort { + COM1 = 0x3F8 +} + +pub struct SerialWriter { + serial_port: SerialPort, +} + +impl SerialWriter { + pub fn new(serial_port: SerialPort) -> SerialWriter { + let port = serial_port as u16; + + unsafe { + outb(port + 1, 0x00); + outb(port + 3, 0x80); + outb(port, 0x03); + outb(port + 1, 0x00); + outb(port + 3, 0x03); + outb(port + 2, 0xC7); + outb(port + 4, 0x0B); + outb(port + 4, 0x1E); + outb(port, 0xAE); + + if inb(port) != 0xAE { + panic!(); + } + + outb(port + 4, 0x0F); + } + + SerialWriter { + serial_port, + } + } + + fn write_byte(&mut self, byte: u8) { + unsafe { + outb(self.serial_port as u16, byte); + } + } + + fn write_newline(&mut self) { + self.write_byte(b'\r'); + self.write_byte(b'\n'); + } +} + +impl core::fmt::Write for SerialWriter { + fn write_str(&mut self, s: &str) -> core::fmt::Result { + for i in s.chars() { + match i { + '\n' => self.write_newline(), + _ => self.write_byte(i as u8), + } + } + + Ok(()) + } +} + +#[macro_export] +macro_rules! print { + ($($args:tt)+) => ({ + use core::fmt::Write; + use crate::arch::amd64::devices::serial::{SerialWriter, SerialPort}; + + let _ = write!(SerialWriter::new(SerialPort::COM1), $($args)+); + }); +} + +#[macro_export] +macro_rules! println { + () => ({ + print!("\n") + }); + ($fmt:expr) => ({ + print!(concat!($fmt, "\n")) + }); + ($fmt:expr, $($args:tt)+) => ({ + print!(concat!($fmt, "\n"), $($args)+) + }); +} \ No newline at end of file diff --git a/src/arch/amd64/instructions.rs b/src/arch/amd64/instructions.rs new file mode 100644 index 0000000..028ad8e --- /dev/null +++ b/src/arch/amd64/instructions.rs @@ -0,0 +1,46 @@ +use core::arch::asm; + +/// Halt +/// +/// Halts the CPU until an interrupt occurs. +pub fn hlt() { + unsafe { + asm!("hlt"); + } +} + +/// Clear Interrupt Flag +/// +/// Clears the IF flag, causing the processor to ignore maskable interrupts. +pub fn cli() { + unsafe { + asm!("cli", options(preserves_flags, nostack)); + } +} + +/// Set Interrupt Flag +/// +/// Sets the IF flag, causing the processor to start accepting maskable interrupts. +pub fn sti() { + unsafe { + asm!("sti", options(preserves_flags, nostack)); + } +} + +/// Write a byte to a port. +pub unsafe fn outb(port: u16, data: u8) { + unsafe { + asm!("outb %al, %dx", in("al") data, in("dx") port, options(att_syntax)); + } +} + +/// Read a byte from a port. +pub unsafe fn inb(port: u16) -> u8 { + let value: u8; + + unsafe { + asm!("inb %dx, %al", in("dx") port, out("al") value, options(att_syntax)); + } + + value +} \ No newline at end of file diff --git a/src/arch/amd64/interrupts/gdt.rs b/src/arch/amd64/interrupts/gdt.rs new file mode 100644 index 0000000..9314372 --- /dev/null +++ b/src/arch/amd64/interrupts/gdt.rs @@ -0,0 +1,96 @@ +use core::ptr::addr_of; +use spin::lazy::Lazy; +use x86_64::PrivilegeLevel::Ring3; +use x86_64::registers::segmentation::{CS, DS, ES, SS}; +use x86_64::structures::gdt::{Descriptor, GlobalDescriptorTable, SegmentSelector}; +use x86_64::structures::tss::TaskStateSegment; +use x86_64::VirtAddr; + +const STACK_SIZE: usize = 1024 * 8 * 16; + +pub const DOUBLE_FAULT_IST_INDEX: u16 = 0; +pub const PAGE_FAULT_IST_INDEX: u16 = 1; +pub const GENERAL_PROTECTION_FAULT_IST_INDEX: u16 = 2; + + +static TSS: Lazy = Lazy::new(|| { + let mut tss = TaskStateSegment::new(); + + tss.privilege_stack_table[0] = { + static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE]; + + let stack_start = unsafe { addr_of!(STACK) } as u64; + let stack_end = stack_start + STACK_SIZE as u64; + + VirtAddr::new(stack_end) + }; + + tss.interrupt_stack_table[DOUBLE_FAULT_IST_INDEX as usize] = { + static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE]; + + let stack_start = unsafe { addr_of!(STACK) } as u64; + let stack_end = stack_start + STACK_SIZE as u64; + + VirtAddr::new(stack_end) + }; + + tss.interrupt_stack_table[PAGE_FAULT_IST_INDEX as usize] = { + static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE]; + + let stack_start = unsafe { addr_of!(STACK) } as u64; + let stack_end = stack_start + STACK_SIZE as u64; + + VirtAddr::new(stack_end) + }; + + tss.interrupt_stack_table[GENERAL_PROTECTION_FAULT_IST_INDEX as usize] = { + static mut STACK: [u8; STACK_SIZE] = [0; STACK_SIZE]; + + let stack_start = unsafe { addr_of!(STACK) } as u64; + let stack_end = stack_start + STACK_SIZE as u64; + + VirtAddr::new(stack_end) + }; + + tss +}); + +pub struct GDTSelectors { + pub code_selector: SegmentSelector, + pub data_selector: SegmentSelector, + pub tss_selector: SegmentSelector, + pub user_code_selector: SegmentSelector, + pub user_data_selector: SegmentSelector, +} + +pub static GDT: Lazy<(GlobalDescriptorTable, GDTSelectors)> = Lazy::new(|| { + let mut gdt = GlobalDescriptorTable::new(); + + let code_selector = gdt.append(Descriptor::kernel_code_segment()); + let data_selector = gdt.append(Descriptor::kernel_data_segment()); + let tss_selector = gdt.append(Descriptor::tss_segment(&TSS)); + + let mut user_code_selector = gdt.append(Descriptor::user_code_segment()); + user_code_selector.set_rpl(Ring3); + + let mut user_data_selector = gdt.append(Descriptor::user_data_segment()); + user_data_selector.set_rpl(Ring3); + + + (gdt, GDTSelectors { code_selector, data_selector, tss_selector, user_code_selector, user_data_selector }) +}); + +pub fn init() { + use x86_64::instructions::tables::load_tss; + use x86_64::instructions::segmentation::{CS, Segment}; + + GDT.0.load(); + unsafe { + CS::set_reg(GDT.1.code_selector); + ES::set_reg(GDT.1.data_selector); + DS::set_reg(GDT.1.data_selector); + SS::set_reg(GDT.1.data_selector); + + load_tss(GDT.1.tss_selector) + } +} \ No newline at end of file diff --git a/src/arch/amd64/interrupts/idt.rs b/src/arch/amd64/interrupts/idt.rs new file mode 100644 index 0000000..6f2cd18 --- /dev/null +++ b/src/arch/amd64/interrupts/idt.rs @@ -0,0 +1,230 @@ +use core::arch::asm; +use spin::lazy::Lazy; +use spin::mutex::Mutex; +use x86_64::registers::control::Cr2; +use x86_64::{set_general_handler, PrivilegeLevel}; +use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame, PageFaultErrorCode}; +use crate::arch::amd64::devices::i8259::PicPair; +use crate::arch::amd64::interrupts::gdt; +use crate::trafficcontrol::Process; + +pub const PIC_1_OFFSET: u8 = 32; +pub const PIC_2_OFFSET: u8 = PIC_1_OFFSET + 8; + +pub static PICS: Mutex = Mutex::new(unsafe { + PicPair::new(PIC_1_OFFSET, PIC_2_OFFSET) +}); + +static IDT: Lazy = Lazy::new(|| { + let mut idt = InterruptDescriptorTable::new(); + + idt.breakpoint.set_handler_fn(breakpoint_handler); + idt.debug.set_handler_fn(debug_handler); + + unsafe { + idt.double_fault.set_handler_fn(double_fault_handler) + .set_stack_index(gdt::DOUBLE_FAULT_IST_INDEX); + }; + + unsafe { + idt.general_protection_fault.set_handler_fn(general_protection_fault_handler) + .set_stack_index(gdt::GENERAL_PROTECTION_FAULT_IST_INDEX); + } + + unsafe { + idt.page_fault.set_handler_fn(page_fault_handler) + .set_stack_index(gdt::PAGE_FAULT_IST_INDEX); + } + + idt[InterruptIndex::Timer as u8].set_handler_fn(timer_interrupt_handler); + + // syscall capture + idt[0x80].set_handler_fn(syscall_handler).set_privilege_level(PrivilegeLevel::Ring3); + + set_general_handler!(&mut idt, catch_all_handler, 0); + set_general_handler!(&mut idt, catch_all_handler, 2); + set_general_handler!(&mut idt, catch_all_handler, 4..=7); + set_general_handler!(&mut idt, catch_all_handler, 9..=12); + set_general_handler!(&mut idt, catch_all_handler, 15..=31); + + idt +}); + +#[repr(u8)] +pub enum InterruptIndex { + Timer = PIC_1_OFFSET, + Keyboard, + Secondary, + SerialTwo, + SerialOne, + ParallelTwo, + Floppy, + ParallelOne, + RealTimeClock = PIC_2_OFFSET, + ACPI, + CustomOne, + CustomTwo, + Mouse, + CoProcessor, + PrimaryATA, + SecondaryATA +} + +pub fn init() { + IDT.load(); +} + +// CPU interrupts +extern "x86-interrupt" fn breakpoint_handler( + interrupt_stack_frame: InterruptStackFrame +) { + println!("breakpoint hit!"); + println!("{:#?}", interrupt_stack_frame); +} + +extern "x86-interrupt" fn debug_handler( + interrupt_stack_frame: InterruptStackFrame +) { + println!("debug hit!"); + println!("{:#?}", interrupt_stack_frame); +} + +extern "x86-interrupt" fn double_fault_handler( + interrupt_stack_frame: InterruptStackFrame, + error_code: u64 +) -> ! { + println!("=== DOUBLE FAULT ==="); + println!("Error code: {:#x}", error_code); + println!("Stack frame: {:#?}", interrupt_stack_frame); + + panic!("Double fault occurred!"); +} + +extern "x86-interrupt" fn general_protection_fault_handler( + interrupt_stack_frame: InterruptStackFrame, + error_code: u64 +) { + println!("=== GENERAL PROTECTION FAULT ==="); + println!("Error code: {:#x} ({:016b})", error_code, error_code); + + if error_code != 0 { + let external = (error_code & 1) != 0; + let table = (error_code >> 1) & 0b11; + let index = (error_code >> 3) & 0x1FFF; + + println!("\tExternal: {}", external); + println!("\tTable: {} ({})", table, match table { + 0 => "GDT", + 1 => "IDT", + 2 => "LDT", + 3 => "IDT", + _ => "Unknown" + }); + println!("\tSelector index: {}", index); + } + + println!("Stack frame: {:#?}", interrupt_stack_frame); + + panic!("General protection fault!"); +} + +extern "x86-interrupt" fn page_fault_handler( + interrupt_stack_frame: InterruptStackFrame, + page_fault_error_code: PageFaultErrorCode +) { + println!("=== PAGE FAULT ==="); + println!("Accessed Address: {:?}", Cr2::read()); + println!("Error Code: {:?}", page_fault_error_code); + println!("Stack frame: {:#?}", interrupt_stack_frame); + + panic!("Page fault!"); +} + +fn catch_all_handler( + interrupt_stack_frame: InterruptStackFrame, + code: u8, + error_code: Option +) { + println!("=== UNHANDLED EXCEPTION {} ===", code); + if let Some(error_code) = error_code { + println!("Error code: {:#x}", error_code); + } + println!("Stack frame: {:#?}", interrupt_stack_frame); + + panic!("Unhandled exception {} occurred!", code); +} + +#[unsafe(no_mangle)] +extern "x86-interrupt" fn timer_interrupt_handler( + interrupt_stack_frame: InterruptStackFrame, +) { + // first thing: save all the gp registers + let mut saved_registers: [u64; 15] = [0; 15]; + unsafe { + asm!( + "mov [{regs} + 0], rax", + "mov [{regs} + 8], rbx", + "mov [{regs} + 16], rcx", + "mov [{regs} + 24], rdx", + "mov [{regs} + 32], rsi", + "mov [{regs} + 40], rdi", + "mov [{regs} + 48], rbp", + "mov [{regs} + 56], r8", + "mov [{regs} + 64], r9", + "mov [{regs} + 72], r10", + "mov [{regs} + 80], r11", + "mov [{regs} + 88], r12", + "mov [{regs} + 96], r13", + "mov [{regs} + 104], r14", + "mov [{regs} + 112], r15", + regs = in(reg) saved_registers.as_mut_ptr(), + ); + } + + // TODO: debug code + println!("."); + + // since we're gonna be jumping, we should notify early bc we wont have a chance to do this + unsafe { + PICS.lock().notify_end_interrupt(InterruptIndex::Timer as u8); + } + + Process::execute_next_round_robin(interrupt_stack_frame, saved_registers); +} + +extern "x86-interrupt" fn syscall_handler( + _interrupt_stack_frame: InterruptStackFrame +) { + let rax: u64; + let rbx: u64; + let rcx: u64; + let rdx: u64; + let rsi: u64; + let rdi: u64; + + unsafe { + asm!( + // llvm will cry about it if we use rbx, move it somewhere else + "mov {rbx_out}, rbx", + out("rax") rax, + rbx_out = out(reg) rbx, + out("rcx") rcx, + out("rdx") rdx, + out("rsi") rsi, + out("rdi") rdi, + options(nostack, preserves_flags) + ); + } + + let result = crate::syscalls::route(rax, rbx, rcx, rdx, rsi, rdi); + + unsafe { + // result goes into rax + // TODO: figure this out better maybe + asm!( + "mov rax, {result_in}", + result_in = in(reg) result, + options(nostack, preserves_flags) + ); + } +} \ No newline at end of file diff --git a/src/arch/amd64/interrupts/mod.rs b/src/arch/amd64/interrupts/mod.rs new file mode 100644 index 0000000..6aed368 --- /dev/null +++ b/src/arch/amd64/interrupts/mod.rs @@ -0,0 +1,2 @@ +pub mod gdt; +pub mod idt; \ No newline at end of file diff --git a/src/arch/amd64/memory/kalloc.rs b/src/arch/amd64/memory/kalloc.rs new file mode 100644 index 0000000..6b93271 --- /dev/null +++ b/src/arch/amd64/memory/kalloc.rs @@ -0,0 +1,41 @@ +use core::ops::Deref; +use linked_list_allocator::LockedHeap; +use x86_64::structures::paging::{FrameAllocator, Mapper, Page, PageTableFlags, Size4KiB}; +use x86_64::VirtAddr; +use crate::arch::amd64::memory::pmm::get_frame_allocator; +use crate::arch::amd64::memory::vmm::get_mapper; + +const HEAP_START: usize = 0x2000_0000_0000; +const HEAP_SIZE: usize = 1024 * 1024 * 32; + +#[global_allocator] +static KALLOC: LockedHeap = LockedHeap::empty(); + +pub fn init() { + let page_range = { + let heap_start = VirtAddr::new(HEAP_START as u64); + let heap_end = heap_start + (HEAP_SIZE) as u64; + + let heap_start_page: Page = Page::containing_address(heap_start); + let heap_end_page: Page = Page::containing_address(heap_end); + + Page::range(heap_start_page, heap_end_page) + }; + + let mut allocator = get_frame_allocator().lock(); + for page in page_range { + if let Some(frame) = allocator.allocate_frame() { + let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE; + + unsafe { + get_mapper().map_to(page, frame, flags, &mut *allocator).expect("Failed to map").flush(); + } + } else { + break; + } + } + + unsafe { + KALLOC.lock().init(HEAP_START as *mut u8, HEAP_SIZE); + } +} \ No newline at end of file diff --git a/src/arch/amd64/memory/mod.rs b/src/arch/amd64/memory/mod.rs new file mode 100644 index 0000000..67ea101 --- /dev/null +++ b/src/arch/amd64/memory/mod.rs @@ -0,0 +1,15 @@ +use core::sync::atomic::Ordering; +use x86_64::{PhysAddr, VirtAddr}; +use x86_64::structures::paging::Translate; + +pub mod kalloc; +pub mod pmm; +pub mod vmm; + +pub fn phys_to_virt(addr: PhysAddr) -> VirtAddr { + VirtAddr::new(addr.as_u64() + vmm::PHYS_OFFSET.load(Ordering::Relaxed) as u64) +} + +pub fn virt_to_phys(addr: VirtAddr) -> Option { + vmm::get_mapper().translate_addr(addr) +} \ No newline at end of file diff --git a/src/arch/amd64/memory/pmm.rs b/src/arch/amd64/memory/pmm.rs new file mode 100644 index 0000000..3e9960d --- /dev/null +++ b/src/arch/amd64/memory/pmm.rs @@ -0,0 +1,233 @@ +use crate::print; +use crate::println; +use core::ptr::slice_from_raw_parts_mut; +use core::sync::atomic::{AtomicUsize, Ordering}; +use limine::memory_map::{Entry, EntryType}; +use spin::{Mutex, Once}; +use x86_64::structures::paging::{FrameAllocator, FrameDeallocator, PhysFrame, Size4KiB}; +use x86_64::PhysAddr; + +// TODO: remake this entire thing + +// TODO: rethink this +static FRAME_ALLOCATOR: Once> = Once::new(); + +// TODO: rethink this +static mut FRAME_BITMAP: [u8; BITMAP_SIZE] = [0; BITMAP_SIZE]; + +// TODO: rethink this +const BITMAP_SIZE: usize = 16384 * 4096 * 4; + +pub const MAX_REGIONS: usize = 64; + +static TOTAL_MEMORY: AtomicUsize = AtomicUsize::new(0); +static ALLOCATED_FRAMES: AtomicUsize = AtomicUsize::new(0); + +#[repr(C)] +#[derive(PartialEq, Eq, Clone, Copy)] +pub struct Region { + /// The base of the memory region, in *physical space*. + pub base: u64, + /// The end address of the memory region, in *physical space* + pub end: u64, + /// The length of the memory region, in bytes. + pub length: u64, + /// The type of the memory region. See [`EntryType`] for specific values. + pub entry_type: EntryType, +} + +pub struct PFrameAllocator { + usable_regions: [Option; MAX_REGIONS], + bitmap_base: u64, + last_allocated: usize, +} + +impl PFrameAllocator { + pub unsafe fn init(memory_map: &[&Entry]) { + let mut i = 0; + let mut usable_regions = [None; MAX_REGIONS]; + let mut total_memory: usize = 0; + let mut min_addr = u64::MAX; + + for e in memory_map { + let region = Region { + base: e.base, + end: e.base + e.length, + length: e.length, + entry_type: e.entry_type, + }; + + if e.entry_type == EntryType::USABLE { + usable_regions[i] = Some(region); + total_memory += e.length as usize; + min_addr = min_addr.min(e.base); + i += 1; + } + } + + let bitmap_base = (min_addr / 4096) * 4096; + + TOTAL_MEMORY.store(total_memory, Ordering::Relaxed); + + #[allow(static_mut_refs)] + FRAME_BITMAP.fill(0); + + FRAME_ALLOCATOR.call_once(|| { + Mutex::new(PFrameAllocator { + usable_regions, + bitmap_base, + last_allocated: 0, + }) + }); + } + + /// Convert physical address to bitmap index + fn addr_to_bitmap_index(&self, addr: u64) -> Option { + if addr < self.bitmap_base { + return None; + } + + let frame_number = (addr - self.bitmap_base) / 4096; + let bit_index = frame_number as usize; + + if bit_index >= BITMAP_SIZE * 8 { + None + } else { + Some(bit_index) + } + } + + /// Convert bitmap index to physical address + fn bitmap_index_to_addr(&self, index: usize) -> u64 { + self.bitmap_base + (index as u64 * 4096) + } + + /// Check if a frame is allocated in the bitmap + fn is_frame_allocated(&self, bit_index: usize) -> bool { + let byte_index = bit_index / 8; + let bit_offset = bit_index % 8; + + if byte_index >= BITMAP_SIZE { + return true; + } + + unsafe { + (FRAME_BITMAP[byte_index] & (1 << bit_offset)) != 0 + } + } + + /// Set a frame as allocated in the bitmap + fn set_frame_allocated(&mut self, bit_index: usize) { + let byte_index = bit_index / 8; + let bit_offset = bit_index % 8; + + if byte_index < BITMAP_SIZE { + unsafe { + FRAME_BITMAP[byte_index] |= 1 << bit_offset; + } + } + } + + /// Set a frame as free in the bitmap + fn set_frame_free(&mut self, bit_index: usize) { + let byte_index = bit_index / 8; + let bit_offset = bit_index % 8; + + if byte_index < BITMAP_SIZE { + unsafe { + FRAME_BITMAP[byte_index] &= !(1 << bit_offset); + } + } + } + + /// Check if an address is in any usable region + fn is_addr_usable(&self, addr: u64) -> bool { + for region_opt in &self.usable_regions { + if let Some(region) = region_opt { + if addr >= region.base && addr < region.end { + return true; + } + } + } + false + } + + fn find_free_frame(&mut self) -> Option> { + let max_frames = BITMAP_SIZE * 8; + + for offset in 0..max_frames { + let index = (self.last_allocated + offset) % max_frames; + + if !self.is_frame_allocated(index) { + let addr = self.bitmap_index_to_addr(index); + + if self.is_addr_usable(addr) { + self.last_allocated = index; + return Some(PhysFrame::containing_address(PhysAddr::new(addr))); + } + } + } + + None + } +} + +unsafe impl FrameAllocator for PFrameAllocator { + fn allocate_frame(&mut self) -> Option> { + if let Some(frame) = self.find_free_frame() { + let addr = frame.start_address().as_u64(); + + if let Some(bit_index) = self.addr_to_bitmap_index(addr) { + print!( + "Found frame at {:#x} ({} bytes)", + addr, + frame.size() + ); + + self.set_frame_allocated(bit_index); + ALLOCATED_FRAMES.fetch_add(1, Ordering::Relaxed); + + // ensure memory is cleared + unsafe { + print!("! Clearing memory..."); + slice_from_raw_parts_mut(addr as *mut u8, frame.size() as usize).as_mut()?.fill(0); + } + + print!(" Allocated!\n"); + + Some(frame) + } else { + println!("cant convert address to bitmap?"); + + None + } + } else { + println!("no free frame :("); + + None + } + } +} + +impl FrameDeallocator for PFrameAllocator { + unsafe fn deallocate_frame(&mut self, frame: PhysFrame) { + let addr = frame.start_address().as_u64(); + + if !self.is_addr_usable(addr) { + return; + } + + if let Some(bit_index) = self.addr_to_bitmap_index(addr) { + if self.is_frame_allocated(bit_index) { + self.set_frame_free(bit_index); + ALLOCATED_FRAMES.fetch_sub(1, Ordering::Relaxed); + + self.last_allocated = bit_index; + } + } + } +} + +pub fn get_frame_allocator() -> &'static Mutex { + FRAME_ALLOCATOR.get().expect("Cannot get frame allocator?") +} diff --git a/src/arch/amd64/memory/vmm.rs b/src/arch/amd64/memory/vmm.rs new file mode 100644 index 0000000..be31170 --- /dev/null +++ b/src/arch/amd64/memory/vmm.rs @@ -0,0 +1,133 @@ +use crate::print; +use core::sync::atomic::{AtomicUsize, Ordering}; +use spin::Once; +use x86_64::registers::control::{Cr3}; +use x86_64::structures::paging::{FrameAllocator, FrameDeallocator, Mapper, OffsetPageTable, Page, PageTable, PageTableFlags, PhysFrame, Size4KiB}; +use x86_64::VirtAddr; +use crate::arch::amd64::memory::{phys_to_virt, pmm}; +use crate::println; + +#[allow(static_mut_refs)] +pub static mut KERNEL_PAGE_TABLE: Once = Once::new(); +pub static PHYS_OFFSET: AtomicUsize = AtomicUsize::new(0); + +pub unsafe fn init(physical_memory_offset: u64) { + PHYS_OFFSET.store(physical_memory_offset as usize, Ordering::Relaxed); + + unsafe { + #[allow(static_mut_refs)] + KERNEL_PAGE_TABLE.call_once(|| { OffsetPageTable::new(&mut *active_l4t(), VirtAddr::new(physical_memory_offset)) }); + } +} + +pub unsafe fn active_l4t() -> &'static mut PageTable { + let (l4tf, _) = Cr3::read(); + + let phys = l4tf.start_address(); + let virt = phys_to_virt(phys); + let page_table_ptr: *mut PageTable = virt.as_mut_ptr(); + + unsafe { &mut *page_table_ptr } +} + +pub fn get_mapper() -> &'static mut OffsetPageTable<'static> { + unsafe { + #[allow(static_mut_refs)] + KERNEL_PAGE_TABLE.get_mut().expect("Cannot get page table?") + } +} + +pub unsafe fn new_page_table(frame: PhysFrame) -> &'static mut PageTable { + let phys_addr = frame.start_address(); + let virt_addr = phys_to_virt(phys_addr); + + let page_table_ptr: *mut PageTable = virt_addr.as_mut_ptr(); + + unsafe { + &mut *page_table_ptr + } +} + +pub fn alloc_pages(page_table: &mut OffsetPageTable, addr: u64, count: usize, flags: PageTableFlags) -> Result<(), ()> { + let mut frame_allocator = pmm::get_frame_allocator().lock(); + + let start_page: Page = Page::containing_address(VirtAddr::new(addr)); + let end_addr = addr + (count * 4096) as u64 - 1; // Last byte of the allocation + let end_page = Page::containing_address(VirtAddr::new(end_addr)); + + let pages = Page::range_inclusive(start_page, end_page); + + let parent_table_flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE | PageTableFlags::USER_ACCESSIBLE; + + for page in pages { + if let Some(frame) = frame_allocator.allocate_frame() { + let res = unsafe { page_table.map_to_with_table_flags(page, frame, flags, parent_table_flags, &mut *frame_allocator) }; + + if let Ok(res) = res { + res.flush(); + } else { + println!("beep"); + return Err(()); + } + } else { + println!("boop"); + return Err(()); + } + } + + Ok(()) +} + +pub fn free_pages(page_table: &mut OffsetPageTable, addr: u64, count: usize) -> Result<(), ()> { + let mut frame_allocator = pmm::get_frame_allocator().lock(); + + let start_page: Page = Page::containing_address(VirtAddr::new(addr)); + let end_addr = addr + (count * 4096) as u64 - 1; + let end_page = Page::containing_address(VirtAddr::new(end_addr)); + + let pages = Page::range_inclusive(start_page, end_page); + + for page in pages { + if let Ok((frame, flush)) = page_table.unmap(page) { + unsafe { + frame_allocator.deallocate_frame(frame); + } + flush.flush(); + } else { + return Err(()) + } + } + + Ok(()) +} + +pub fn find_free_virtual_address(size: usize) -> Option { + let mapper = get_mapper(); + let page_size = 4096; + let pages_needed = size.div_ceil(page_size); + + let mut current_addr = 0x20000000u64; + + while current_addr + (pages_needed as u64 * page_size as u64) < u64::MAX { + let mut all_free = true; + + // lets check if all required pages are free + for i in 0..pages_needed { + let check_addr = current_addr + (i as u64 * page_size as u64); + let page: Page = Page::containing_address(VirtAddr::new(check_addr)); + + if mapper.translate_page(page).is_ok() { + all_free = false; + break; + } + } + + if all_free { + return Some(current_addr); + } + + current_addr += page_size as u64; + } + + None +} \ No newline at end of file diff --git a/src/arch/amd64/mod.rs b/src/arch/amd64/mod.rs new file mode 100644 index 0000000..bdbcef3 --- /dev/null +++ b/src/arch/amd64/mod.rs @@ -0,0 +1,26 @@ +use core::panic; + +pub mod memory; +pub mod port; +#[macro_use] +pub mod devices; +pub mod instructions; +pub mod interrupts; + +#[panic_handler] +fn on_panic(info: &panic::PanicInfo) -> ! { + println!(); + println!("################################### fucky wucky! ###################################"); + println!("{:#?}", info); + println!("halting..."); + + catch_fire() +} + +pub fn catch_fire() -> ! { + instructions::cli(); + + loop { + instructions::hlt() + } +} \ No newline at end of file diff --git a/src/arch/amd64/port.rs b/src/arch/amd64/port.rs new file mode 100644 index 0000000..08d3677 --- /dev/null +++ b/src/arch/amd64/port.rs @@ -0,0 +1,27 @@ +use core::arch::asm; + +pub struct Port { + port: u16 +} + +impl Port { + pub const fn new(port: u16) -> Port { + Port { port } + } + + pub unsafe fn write_u8(&mut self, value: u8) { + unsafe { + asm!("out dx, al", in("dx") self.port, in("al") value, options(nomem, nostack, preserves_flags)); + } + } + + pub unsafe fn read_u8(&mut self) -> u8 { + let value: u8; + + unsafe { + asm!("in al, dx", in("dx") self.port, out("al") value, options(nomem, nostack, preserves_flags)); + } + + value + } +} \ No newline at end of file diff --git a/src/arch/mod.rs b/src/arch/mod.rs new file mode 100644 index 0000000..ba69b33 --- /dev/null +++ b/src/arch/mod.rs @@ -0,0 +1 @@ +pub mod amd64; \ No newline at end of file diff --git a/src/main.rs b/src/main.rs new file mode 100644 index 0000000..90914ed --- /dev/null +++ b/src/main.rs @@ -0,0 +1,173 @@ +#![feature(abi_x86_interrupt)] +#![no_std] +#![no_main] +extern crate alloc; + +use alloc::boxed::Box; +use alloc::vec::Vec; +use core::arch::asm; +use core::ptr; +use core::ptr::{addr_of, addr_of_mut}; +use elf::ElfBytes; +use elf::endian::AnyEndian; +use limine::BaseRevision; +use limine::request::{BootloaderInfoRequest, HhdmRequest, MemoryMapRequest, ModuleRequest, PagingModeRequest}; +use tar_no_std::TarArchiveRef; +use crate::arch::amd64; +use crate::arch::amd64::{catch_fire, instructions}; +use crate::arch::amd64::interrupts::{gdt, idt}; +use crate::arch::amd64::memory::{kalloc, pmm, vmm}; + +mod arch; +mod syscalls; +mod trafficcontrol; + +pub const KERNEL_VERSION: &str = env!("CARGO_PKG_VERSION"); + +// Limine requests +#[used] +static BASE_REVISION: BaseRevision = BaseRevision::new(); + +#[used] +static BOOTLOADER_INFO_REQUEST: BootloaderInfoRequest = BootloaderInfoRequest::new(); + +#[used] +static PAGING_MODE_REQUEST: PagingModeRequest = PagingModeRequest::new().with_mode(limine::paging::Mode::FOUR_LEVEL); + +#[used] +static MEMORY_MAP_REQUEST: MemoryMapRequest = MemoryMapRequest::new(); + +#[used] +static HHDM_REQUEST: HhdmRequest = HhdmRequest::new(); + +#[used] +static MODULE_REQUEST: ModuleRequest = ModuleRequest::new(); + +#[unsafe(no_mangle)] +pub extern "C" fn _kmain() -> ! { + assert!(BASE_REVISION.is_supported()); + + println!("haii from hypericum v{}", KERNEL_VERSION); + + if let Some(inf) = BOOTLOADER_INFO_REQUEST.get_response() { + println!("booted using {} v{} r{}", inf.name(), inf.version(), inf.revision()); + } else { + println!("weird... no bootloader info... is this not limine?"); + } + + print!("init gdt"); + gdt::init(); + println!("\t\t\t\t\t[OK]"); + + print!("init interrupts"); + // disable interrupts while we do all this set-up + amd64::instructions::cli(); + idt::init(); + println!("\t\t\t\t\t[OK]"); + + println!("init memory ..."); + + // lets see if our paging mode is here (and correct) + print!("\tgetting paging mode"); + if let Some(pag) = PAGING_MODE_REQUEST.get_response() { + assert!(pag.mode() == limine::paging::Mode::FOUR_LEVEL); + println!("\t\t\t[OK]"); + } else { + println!("\t\t\t[ERR]"); + panic!("okay we're missing our paging mode, something has gone wrong") + } + + // get limine memory map + print!("\tgetting memory map data"); + let mem_map_res = MEMORY_MAP_REQUEST.get_response().expect("missing limine memory map data"); + let base_mem_offset = HHDM_REQUEST.get_response().expect("missing higher half memory data"); + println!("\t\t\t[OK]"); + + print!("\tgetting frame allocator"); + unsafe { pmm::PFrameAllocator::init(mem_map_res.entries()) }; + println!("\t\t\t[OK]"); + + print!("\tpaging init"); + unsafe { vmm::init(base_mem_offset.offset()) }; + println!("\t\t\t\t[OK]"); + + print!("\tkernel memory init"); + unsafe { kalloc::init() } + println!("\t\t\t[OK]"); + + print!("starting interrupts"); + unsafe { + // ensure interrupts are disabled + amd64::instructions::cli(); + + // initialize PICs + amd64::devices::i8259::PICS.lock().init(); + + // enable interrupts + amd64::instructions::sti(); + }; + println!("\t\t\t\t[OK]"); + + println!("testing kernel ..."); + + print!("\ttesting kernel heap: "); + let heap_value = Box::new(42); + + assert_eq!(heap_value, Box::new(42_u64)); + + print!("{}", heap_value); + + println!("\t\t\t[OK]"); + + print!("\ttesting syscall interrupt"); + libgoatweed::syscalls::k_test(); + + println!("kernel load complete"); + + println!("loading initramfs"); + // get the initramfs location in memory from limine and turn it into a slice we can use + let initramfs = MODULE_REQUEST.get_response().expect("missing module info!").modules().first().expect("missing initramfs!"); + let initramfs_bytes = unsafe { &*ptr::slice_from_raw_parts(initramfs.addr(), initramfs.size() as usize) }; + + // parse the tar so we can go through it + let initramfs = TarArchiveRef::new(initramfs_bytes).expect("initramfs not valid"); + let mut initramfs_iter = initramfs.entries(); + + println!("spawning init"); + // look through the initramfs tar to find a valid elf called init + let init: Option<&[u8]> = loop { + if let Some(i) = initramfs_iter.next() { + if i.filename().as_str().expect("invalid file name").eq("init") { + let elf = ElfBytes::::minimal_parse(&i.data()); + + match elf { + Ok(_) => { + break Some(i.data()) + } + Err(_) => { + break None + } + } + } + } else { + break None + } + }; + + + // ensure init exists and then copy it into kernel memory + let init: Vec = if let Some(init) = init { + init.to_vec() + } else { + panic!("no init, halting..."); + }; + + // call pspawn to start init + // TODO: we do it twice here to debug, we can make it one once we have init working + libgoatweed::syscalls::p_spawn(init.as_ptr(), init.len()); + // libgoatweed::syscalls::p_spawn(init.as_ptr(), init.len()); + + loop { + instructions::hlt() + } +} \ No newline at end of file diff --git a/src/syscalls/m_map.rs b/src/syscalls/m_map.rs new file mode 100644 index 0000000..6a6099b --- /dev/null +++ b/src/syscalls/m_map.rs @@ -0,0 +1,67 @@ +use core::sync::atomic::Ordering; +use x86_64::registers::control::{Cr3, Cr3Flags}; +use x86_64::structures::paging::{OffsetPageTable, PageTableFlags}; +use x86_64::VirtAddr; +use crate::arch::amd64::memory::vmm; +use crate::arch::amd64::memory::vmm::{active_l4t, alloc_pages, find_free_virtual_address, free_pages}; +use crate::trafficcontrol::{CURRENT_PROCESS, PROCESSES}; + +/// +pub fn m_map(size: usize) -> *mut u8 { + let start_addr = find_free_virtual_address(size); + + if start_addr.is_none() { + // TODO: return with Err and a error code + return core::ptr::null_mut(); + } + + let start_addr = start_addr.unwrap(); + + // swap to the process page table here + let previous_cr3 = Cr3::read(); + + let processes = PROCESSES.read(); + let process = processes.get(&CURRENT_PROCESS.load(Ordering::SeqCst)).expect("Proccess called m_map while missing?"); + + unsafe { + Cr3::write(process.page_table, Cr3Flags::empty()) + } + + let mut mapper = unsafe { OffsetPageTable::new(active_l4t(), VirtAddr::new(vmm::PHYS_OFFSET.load(Ordering::Relaxed) as u64)) }; + let value; + + if alloc_pages(&mut mapper, start_addr, size, PageTableFlags::PRESENT | PageTableFlags::WRITABLE | PageTableFlags::USER_ACCESSIBLE).is_ok() { + value = start_addr as *mut u8 + } else { + value = core::ptr::null_mut() + } + + // anddd switch back + unsafe { + Cr3::write(previous_cr3.0, previous_cr3.1); + } + + value +} + +/// +pub fn m_unmap(addr: *const u8, size: usize) { + // swap to the process page table here + let previous_cr3 = Cr3::read(); + + let processes = PROCESSES.read(); + let process = processes.get(&CURRENT_PROCESS.load(Ordering::SeqCst)).expect("Proccess called m_unmap while missing?"); + + unsafe { + Cr3::write(process.page_table, Cr3Flags::empty()) + } + + let mut mapper = unsafe { OffsetPageTable::new(active_l4t(), VirtAddr::new(vmm::PHYS_OFFSET.load(Ordering::Relaxed) as u64)) }; + + free_pages(&mut mapper, addr as u64, size).unwrap(); + + // anddd switch back + unsafe { + Cr3::write(previous_cr3.0, previous_cr3.1) + } +} \ No newline at end of file diff --git a/src/syscalls/mod.rs b/src/syscalls/mod.rs new file mode 100644 index 0000000..2018ee0 --- /dev/null +++ b/src/syscalls/mod.rs @@ -0,0 +1,38 @@ +use crate::print; +use crate::println; +use crate::syscalls::p_spawn::p_spawn; +use libgoatweed::syscalls::Syscall; +use crate::syscalls::m_map::{m_map, m_unmap}; + +pub mod p_spawn; +pub mod m_map; + +pub fn route(rax: u64, rbx: u64, rcx: u64, _rdx: u64, _rsi: u64, _rdi: u64) -> u64 { + let syscall: Syscall = rax.into(); + + match syscall { + Syscall::PSpawn => { + p_spawn(rbx as *mut u8, rcx as usize); + 0 + }, + Syscall::KQuirky => { + println!("haii from {}", rbx); + 0 + } + Syscall::KTest => { + println!("\t\t[OK]"); + 0 + } + Syscall::MMap => { + m_map(rbx as usize) as u64 + } + Syscall::MUnmap => { + m_unmap(rbx as *const u8, rcx as usize); + 0 + } + _ => { + println!("Invalid syscall: {}", rax); + 0 + } + } +} \ No newline at end of file diff --git a/src/syscalls/p_spawn.rs b/src/syscalls/p_spawn.rs new file mode 100644 index 0000000..baf619c --- /dev/null +++ b/src/syscalls/p_spawn.rs @@ -0,0 +1,15 @@ +use core::slice; +use crate::{print, trafficcontrol}; +use crate::println; + +/// +pub fn p_spawn(elf_location: *mut u8, elf_length: usize) { + println!("location: {:#?}, length: {}", elf_location, elf_length); + + if elf_location.is_null() { + println!("null pointer"); + return; + } + + trafficcontrol::Process::spawn(unsafe { slice::from_raw_parts(elf_location, elf_length) }); +} \ No newline at end of file diff --git a/src/trafficcontrol/mod.rs b/src/trafficcontrol/mod.rs new file mode 100644 index 0000000..f67f763 --- /dev/null +++ b/src/trafficcontrol/mod.rs @@ -0,0 +1,275 @@ +use crate::print; +use alloc::boxed::Box; +use alloc::collections::VecDeque; +use alloc::sync::Arc; +use core::arch::asm; +use core::ptr; +use core::sync::atomic::{AtomicUsize, Ordering}; +use elf::ElfBytes; +use elf::endian::AnyEndian; +use spin::lazy::Lazy; +use spin::rwlock::RwLock; +use x86_64::registers::control::{Cr3, Cr3Flags}; +use x86_64::structures::idt::{InterruptStackFrame}; +use x86_64::structures::paging::{FrameAllocator, Mapper, OffsetPageTable, Page, PageTableFlags, PhysFrame, Size4KiB}; +use x86_64::VirtAddr; +use crate::arch::amd64; +use crate::arch::amd64::interrupts::gdt::GDT; +use crate::arch::amd64::memory::{pmm, vmm}; +use crate::println; +use elf::abi; +use hashbrown::HashMap; + +static PID: AtomicUsize = AtomicUsize::new(0); + +pub static CURRENT_PROCESS: AtomicUsize = AtomicUsize::new(usize::MAX); // MAX = no process + +pub static PROCESSES: Lazy>>> = Lazy::new(|| { + RwLock::new(HashMap::new()) +}); + +static PROCESS_QUEUE: Lazy>> = Lazy::new(|| { + RwLock::new(VecDeque::new()) +}); + +#[derive(Clone)] +pub struct Process { + pub id: usize, + pub parent: Option>, + instruction_pointer: u64, + stack_pointer: u64, + pub page_table: PhysFrame, + saved_registers: [u64; 15] +} + +impl Process { + pub fn spawn(elf: &[u8]) { + if let Ok(pid) = Self::load(elf) { + println!("pid: {} created", pid); + } else { + panic!("failed to spawn process!"); + } + } + + pub fn load(elf: &[u8]) -> Result { + let page_table_frame = pmm::get_frame_allocator().lock().allocate_frame().expect("Failed to allocate frame"); + let page_table = unsafe { vmm::new_page_table(page_table_frame) }; + let kernel_page_table = unsafe { vmm::active_l4t() }; + let kernel_table_frame = Cr3::read().0; + + // this may seem weird to do for security since this allows you to get the kernel layout + // in userspace (which is a valid issue) but we need to be able to have kernel code + // running when we switch into the process and writing KPTI seems like hell at this stage + // darn you meltdown and spectre and friends + let pages = page_table.iter_mut().zip(kernel_page_table.iter()); + for (process, kernel) in pages { + *process = kernel.clone(); + } + + let mut mapper = unsafe { OffsetPageTable::new(page_table, VirtAddr::new(vmm::PHYS_OFFSET.load(Ordering::Relaxed) as u64)) }; + + // 128KB stack here, linux does 1MB so idk probably fine + const USER_STACK_TOP: u64 = 0x7000_0000_0000; + const STACK_SIZE_PAGES: usize = 32; + const STACK_SIZE_BYTES: u64 = (STACK_SIZE_PAGES * 4096) as u64; + let stack_bottom = USER_STACK_TOP - STACK_SIZE_BYTES; + + println!("Allocating stack: bottom={:#x}, top={:#x}, size={}KB", + stack_bottom, USER_STACK_TOP, STACK_SIZE_BYTES / 1024); + + vmm::alloc_pages( + &mut mapper, + stack_bottom, + STACK_SIZE_PAGES, + PageTableFlags::PRESENT | PageTableFlags::WRITABLE | PageTableFlags::USER_ACCESSIBLE + ).expect("Failed to allocate user stack"); + + let initial_stack_pointer = USER_STACK_TOP - 64; + let elf_parse = ElfBytes::::minimal_parse(elf).expect("Invalid elf!"); + let entry = elf_parse.ehdr.e_entry; + + for segment in elf_parse.segments().expect("Missing segments?") { + if segment.p_type == abi::PT_LOAD { + let start_vaddr = segment.p_vaddr; + let end_vaddr = segment.p_vaddr + segment.p_memsz; + + let start_page = VirtAddr::new(start_vaddr).align_down(4096u64).as_u64(); + let end_page = VirtAddr::new(end_vaddr - 1).align_up(4096u64).as_u64(); + let num_pages = ((end_page - start_page) / 4096) as usize; + + // make all segments writable for the copy operation + let mut temp_flags = PageTableFlags::PRESENT | PageTableFlags::USER_ACCESSIBLE | PageTableFlags::WRITABLE; + + // we can still respect the executable flag from the start though + if segment.p_flags & abi::PF_X == 0 { // not executable + temp_flags |= PageTableFlags::NO_EXECUTE; + } + + vmm::alloc_pages(&mut mapper, start_page, num_pages, temp_flags)?; + } + } + + for i in elf_parse.segments().expect("Missing segments?") { + if i.p_type == abi::PT_LOAD { + let segment_data = elf.as_ptr().wrapping_add(i.p_offset as usize); + unsafe { + let (_, cr3_flags) = Cr3::read(); + Cr3::write(page_table_frame, cr3_flags); + + if i.p_filesz > 0 { + ptr::copy_nonoverlapping(segment_data, i.p_vaddr as *mut u8, i.p_filesz as usize); + } + if i.p_memsz > i.p_filesz { + ptr::write_bytes((i.p_vaddr + i.p_filesz) as *mut u8, 0, (i.p_memsz - i.p_filesz) as usize); + } + + Cr3::write(kernel_table_frame, cr3_flags); + } + } + } + + // ok now that we have copied the data, write protect the read only sections + for segment in elf_parse.segments().expect("Missing segments?") { + if segment.p_type == abi::PT_LOAD { + let start_vaddr = segment.p_vaddr; + let end_vaddr = segment.p_vaddr + segment.p_memsz; + + let start_page_addr = VirtAddr::new(start_vaddr).align_down(4096u64); + let end_page_addr = VirtAddr::new(end_vaddr).align_up(4096u64); + + // we should calculate the final flags here + let mut final_flags = PageTableFlags::PRESENT | PageTableFlags::USER_ACCESSIBLE; + if segment.p_flags & abi::PF_W != 0 { + final_flags |= PageTableFlags::WRITABLE; + } + if segment.p_flags & abi::PF_X == 0 { + final_flags |= PageTableFlags::NO_EXECUTE; + } + + let mut current_addr = start_page_addr; + while current_addr < end_page_addr { + let page: Page = Page::from_start_address(current_addr) + .expect("Address not page aligned"); + unsafe { + // anndd finally replace the flags + mapper.update_flags(page, final_flags) + .expect("update_flags failed") + .flush(); + } + current_addr += 4096u64; + } + } + } + + let pid = PID.fetch_add(1, Ordering::SeqCst); + let process = Process { + id: pid, + parent: None, + instruction_pointer: entry, + stack_pointer: initial_stack_pointer, + page_table: page_table_frame, + saved_registers: [0; 15], + }; + + let mut processes = PROCESSES.write(); + let mut queue = PROCESS_QUEUE.write(); + + processes.insert(pid, Box::new(process)); + queue.push_back(pid); + + println!("Created process {} with entry={:#x}, stack={:#x}", pid, entry, initial_stack_pointer); + Ok(pid) + } + + pub fn start(&self) { + println!("Running pid {}", self.id); + + // lets not clobber the stack or anything with a timer intr + amd64::instructions::cli(); + + // swap to the process's page table + unsafe { + Cr3::write(self.page_table, Cr3Flags::empty()); + } + + unsafe { + asm!( + // TODO: figure out why the gp registers cause issues + "mov rax, [{regs} + 0]", + "mov rbx, [{regs} + 8]", + "mov rcx, [{regs} + 16]", + "mov rdx, [{regs} + 24]", + "mov rsi, [{regs} + 32]", + "mov rdi, [{regs} + 40]", + "mov rbp, [{regs} + 48]", + "mov r8, [{regs} + 56]", + "mov r9, [{regs} + 64]", + "mov r10, [{regs} + 72]", + "mov r11, [{regs} + 80]", + "mov r12, [{regs} + 88]", + "mov r13, [{regs} + 96]", + "mov r14, [{regs} + 104]", + "mov r15, [{regs} + 112]", + + // all the segments restore here + "mov ds, {data_seg:x}", + "mov es, {data_seg:x}", + "mov fs, {data_seg:x}", + "mov gs, {data_seg:x}", + + // iretq stack frame goes here + "push {data_seg:r}", + "push {stack_ptr}", + "push {rflags}", + "push {code_seg:r}", + "push {instruction_pointer}", + + // lets jump back + "iretq", + + regs = in(reg) self.saved_registers.as_ptr(), + + data_seg = in(reg) GDT.1.user_data_selector.0, + code_seg = in(reg) GDT.1.user_code_selector.0, + + stack_ptr = in(reg) self.stack_pointer, + instruction_pointer = in(reg) self.instruction_pointer, + + rflags = in(reg) 0x200_u64, // this will reenable interrupts + + options(noreturn) + ); + } + } + + pub fn execute_next_round_robin(interrupt_stack_frame: InterruptStackFrame, saved_registers: [u64; 15]) { + let mut queue = PROCESS_QUEUE.write(); + let mut processes = PROCESSES.write(); + if queue.is_empty() || processes.is_empty() { + return; + } + + let current_pid = CURRENT_PROCESS.load(Ordering::SeqCst); + if current_pid != usize::MAX { + if let Some(process) = processes.get_mut(¤t_pid) { + process.saved_registers = saved_registers; + process.instruction_pointer = interrupt_stack_frame.instruction_pointer.as_u64(); + process.stack_pointer = interrupt_stack_frame.stack_pointer.as_u64(); + } + } + + queue.rotate_left(1); + + let new_pid = queue.front().expect("Missing next pid in queue?"); + + if let Some(process) = processes.get(new_pid) { + let process = process.as_ref().clone(); + drop(processes); + drop(queue); + + CURRENT_PROCESS.store(process.id, Ordering::SeqCst); + + process.start(); + } + } +} \ No newline at end of file