Move all use statements to the beginning of the file

Signed-off-by: SlyMarbo <[email protected]>

Author: SlyMarbo

kernel/src/interrupts.rs

@@ -1,6 +1,7 @@
 use crate::{gdt, halt_loop, println, time};
 use lazy_static::lazy_static;
 use pic8259::ChainedPics;
+use x86_64::registers::control::Cr2;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame, PageFaultErrorCode};
 
 pub fn init() {
@@ -33,8 +34,6 @@ extern "x86-interrupt" fn page_fault_handler(
     stack_frame: InterruptStackFrame,
     error_code: PageFaultErrorCode,
 ) {
-    use x86_64::registers::control::Cr2;
-
     println!("EXCEPTION: PAGE FAULT");
     println!("Accessed Address: {:?}", Cr2::read());
     println!("Error Code: {:?}", error_code);

kernel/src/lib.rs

@@ -10,6 +10,7 @@
 extern crate alloc;
 
 use core::panic::PanicInfo;
+use x86_64::instructions::port::Port;
 
 pub mod allocator;
 pub mod gdt;
@@ -114,8 +115,6 @@ pub enum QemuExitCode {
 /// exit code.
 ///
 pub fn exit_qemu(exit_code: QemuExitCode) {
-    use x86_64::instructions::port::Port;
-
     unsafe {
         let mut port = Port::new(0xf4);
         port.write(exit_code as u32);

kernel/src/memory.rs

@@ -1,4 +1,5 @@
 use bootloader::bootinfo::{MemoryMap, MemoryRegionType};
+use x86_64::registers::control::Cr3;
 use x86_64::structures::paging::{FrameAllocator, OffsetPageTable, PageTable, PhysFrame, Size4KiB};
 use x86_64::{PhysAddr, VirtAddr};
 
@@ -30,8 +31,6 @@ pub unsafe fn init(physical_memory_offset: VirtAddr) -> OffsetPageTable<'static>
 /// behavior).
 ///
 unsafe fn active_level_4_table(physical_memory_offset: VirtAddr) -> &'static mut PageTable {
-    use x86_64::registers::control::Cr3;
-
     let (level_4_table_frame, _) = Cr3::read();
 
     let phys = level_4_table_frame.start_address();

kernel/src/serial.rs

@@ -1,6 +1,8 @@
+use core::fmt::Write;
 use lazy_static::lazy_static;
 use spin::Mutex;
 use uart_16550::SerialPort;
+use x86_64::instructions::interrupts;
 
 lazy_static! {
     pub static ref SERIAL1: Mutex<SerialPort> = {
@@ -15,9 +17,6 @@ lazy_static! {
 ///
 #[doc(hidden)]
 pub fn _print(args: ::core::fmt::Arguments) {
-    use core::fmt::Write;
-    use x86_64::instructions::interrupts;
-
     interrupts::without_interrupts(|| {
         SERIAL1
             .lock()

kernel/src/time.rs

@@ -1,5 +1,6 @@
 use crate::{print, Locked};
 use lazy_static::lazy_static;
+use x86_64::instructions::port::Port;
 
 pub fn init() {
     set_ticker_frequency(TICKS_PER_SECOND);
@@ -18,8 +19,6 @@ const MIN_FREQUENCY: usize = 18; // See https://wiki.osdev.org/Programmable_Inte
 const MAX_FREQUENCY: usize = 1193181;
 
 pub fn set_ticker_frequency(mut freq: usize) {
-    use x86_64::instructions::port::Port;
-
     if freq < MIN_FREQUENCY {
         freq = MIN_FREQUENCY;
     }

kernel/tests/heap_allocation.rs

@@ -9,15 +9,14 @@ extern crate alloc;
 use alloc::{boxed::Box, vec::Vec};
 use bootloader::{entry_point, BootInfo};
 use core::panic::PanicInfo;
+use kernel::allocator;
 use kernel::allocator::HEAP_SIZE;
+use kernel::memory::{self, BootInfoFrameAllocator};
+use x86_64::VirtAddr;
 
 entry_point!(main);
 
 fn main(boot_info: &'static BootInfo) -> ! {
-    use kernel::allocator;
-    use kernel::memory::{self, BootInfoFrameAllocator};
-    use x86_64::VirtAddr;
-
     kernel::init();
     let phys_mem_offset = VirtAddr::new(boot_info.physical_memory_offset);
     let mut mapper = unsafe { memory::init(phys_mem_offset) };