Fill in all exception and IRQ entries. Handle PIT, keyboard IRQs

arch/x86_64/Cargo.toml

@@ -8,5 +8,5 @@ hole_list_allocator = { path = "../../alloc/hole_list_allocator"}
 spin = "*"
 
 [dependencies.x86]
-default-features = false
 version = "0.7.1"
+default-features = false

arch/x86_64/src/context.rs

@@ -1,4 +1,3 @@
-use core::mem;
 use core::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
 
 /// This must be used by the kernel to ensure that context switches are done atomically

arch/x86_64/src/device/display.rs

@@ -1,7 +1,6 @@
 use core::slice;
 use spin::Mutex;
 
-use externs::memset;
 use memory::Frame;
 use paging::{ActivePageTable, PhysicalAddress, entry};
 

arch/x86_64/src/device/mod.rs

@@ -0,0 +1,9 @@
+use paging::ActivePageTable;
+
+pub mod display;
+pub mod ps2;
+
+pub unsafe fn init(active_table: &mut ActivePageTable){
+    display::init(active_table);
+    ps2::init();
+}

arch/x86_64/src/device/ps2.rs

@@ -0,0 +1,73 @@
+use spin::Mutex;
+
+use io::{Io, Pio, ReadOnly, WriteOnly};
+
+pub static PS2: Mutex<Ps2> = Mutex::new(Ps2::new());
+
+pub unsafe fn init() {
+    PS2.lock().init();
+}
+
+mod status {
+    bitflags! {
+        pub flags Flags: u8 {
+            const OUTPUT_FULL = 1,
+            const INPUT_FULL = 1 << 1,
+            const SYSTEM = 1 << 2,
+            const COMMAND = 1 << 3,
+            const TIME_OUT = 1 << 6,
+            const PARITY = 1 << 7
+        }
+    }
+}
+
+mod config {
+    bitflags! {
+        pub flags Flags: u8 {
+            const FIRST_INTERRUPT = 1,
+            const SECOND_INTERRUPT = 1 << 1,
+            const SYSTEM = 1 << 2,
+            const FIRST_DISABLE = 1 << 4,
+            const SECOND_DISABLE = 1 << 5,
+            const FIRST_TRANSLATE = 1 << 6
+        }
+    }
+}
+
+#[repr(u8)]
+enum Command {
+    ReadConfig = 0x20,
+    WriteConfig = 0x60,
+    DisableSecond = 0xA7,
+    EnableSecond = 0xA8,
+    TestSecond = 0xA9,
+    TestController = 0xAA,
+    TestFirst = 0xAB,
+    Diagnostic = 0xAC,
+    DisableFirst = 0xAD,
+    EnableFirst = 0xAE,
+    WriteSecond = 0xD4
+}
+
+pub struct Ps2 {
+    pub data: Pio<u8>,
+    pub status: ReadOnly<Pio<u8>>,
+    pub command: WriteOnly<Pio<u8>>
+}
+
+impl Ps2 {
+    pub const fn new() -> Ps2 {
+        Ps2 {
+            data: Pio::new(0x60),
+            status: ReadOnly::new(Pio::new(0x64)),
+            command: WriteOnly::new(Pio::new(0x64))
+        }
+    }
+
+    pub fn init(&mut self) {
+        print!("Status {:?}\n", status::Flags::from_bits_truncate(self.status.read()));
+
+        self.command.write(Command::ReadConfig as u8);
+        print!("Config {:?}\n", config::Flags::from_bits_truncate(self.data.read()));
+    }
+}

arch/x86_64/src/idt.rs

@@ -1,7 +1,7 @@
 use core::mem;
 use x86::dtables::{self, DescriptorTablePointer};
 
-use interrupt::halt;
+use interrupt::*;
 
 pub static mut IDTR: DescriptorTablePointer = DescriptorTablePointer {
     limit: 0,
@@ -14,69 +14,56 @@ pub unsafe fn init() {
     IDTR.limit = (IDT.len() * mem::size_of::<IdtEntry>() - 1) as u16;
     IDTR.base = IDT.as_ptr() as u64;
 
-    for entry in IDT[0..32].iter_mut() {
-        entry.set_flags(IDT_PRESENT | IDT_RING_0 | IDT_INTERRUPT);
-        entry.set_offset(8, exception as usize);
-    }
-    IDT[13].set_offset(8, protection_fault as usize);
-    IDT[14].set_offset(8, page_fault as usize);
-    for entry in IDT[32..].iter_mut() {
-        entry.set_flags(IDT_PRESENT | IDT_RING_0 | IDT_INTERRUPT);
-        entry.set_offset(8, blank as usize);
-    }
-    IDT[0x80].set_offset(8, syscall as usize);
+    // Set up exceptions
+    IDT[0].set_func(exception::divide_by_zero);
+    IDT[1].set_func(exception::debug);
+    IDT[2].set_func(exception::non_maskable);
+    IDT[3].set_func(exception::breakpoint);
+    IDT[4].set_func(exception::overflow);
+    IDT[5].set_func(exception::bound_range);
+    IDT[6].set_func(exception::invalid_opcode);
+    IDT[7].set_func(exception::device_not_available);
+    IDT[8].set_func(exception::double_fault);
+    // 9 no longer available
+    IDT[10].set_func(exception::invalid_tss);
+    IDT[11].set_func(exception::segment_not_present);
+    IDT[12].set_func(exception::stack_segment);
+    IDT[13].set_func(exception::protection);
+    IDT[14].set_func(exception::page);
+    // 15 reserved
+    IDT[16].set_func(exception::fpu);
+    IDT[17].set_func(exception::alignment_check);
+    IDT[18].set_func(exception::machine_check);
+    IDT[19].set_func(exception::simd);
+    IDT[20].set_func(exception::virtualization);
+    // 21 through 29 reserved
+    IDT[30].set_func(exception::security);
+    // 31 reserved
+
+    // Set up IRQs
+    IDT[32].set_func(irq::pit);
+    IDT[33].set_func(irq::keyboard);
+    IDT[34].set_func(irq::cascade);
+    IDT[35].set_func(irq::com2);
+    IDT[36].set_func(irq::com1);
+    IDT[37].set_func(irq::lpt2);
+    IDT[38].set_func(irq::floppy);
+    IDT[39].set_func(irq::lpt1);
+    IDT[40].set_func(irq::rtc);
+    IDT[41].set_func(irq::pci1);
+    IDT[42].set_func(irq::pci2);
+    IDT[43].set_func(irq::pci3);
+    IDT[44].set_func(irq::mouse);
+    IDT[45].set_func(irq::fpu);
+    IDT[46].set_func(irq::ata1);
+    IDT[47].set_func(irq::ata2);
+
+    // Set syscall function
+    IDT[0x80].set_func(syscall::syscall);
 
     dtables::lidt(&IDTR);
 }
 
-interrupt!(blank, {
-
-});
-
-interrupt!(exception, {
-    println!("EXCEPTION");
-    loop {
-        halt();
-    }
-});
-
-interrupt_error!(protection_fault, {
-    println!("PROTECTION FAULT");
-    loop {
-        halt();
-    }
-});
-
-interrupt_error!(page_fault, {
-    println!("PAGE FAULT");
-    loop {
-        halt();
-    }
-});
-
-#[naked]
-pub unsafe extern fn syscall() {
-    extern {
-        fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize) -> usize;
-    }
-
-    let a;
-    let b;
-    let c;
-    let d;
-    let e;
-    let f;
-    asm!("" : "={rax}"(a), "={rbx}"(b), "={rcx}"(c), "={rdx}"(d), "={rsi}"(e), "={rdi}"(f)
-        : : : "intel", "volatile");
-
-    let a = syscall(a, b, c, d, e, f);
-
-    asm!("" : : "{rax}"(a) : : "intel", "volatile");
-
-    // Pop scratch registers, error code, and return
-    asm!("iretq" : : : : "intel", "volatile");
-}
-
 bitflags! {
     pub flags IdtFlags: u8 {
         const IDT_PRESENT = 1 << 7,
@@ -142,4 +129,10 @@ impl IdtEntry {
         self.offsetm = (base >> 16) as u16;
         self.offseth = (base >> 32) as u32;
     }
+
+    // A function to set the offset more easily
+    pub fn set_func(&mut self, func: unsafe extern fn()) {
+        self.set_flags(IDT_PRESENT | IDT_RING_0 | IDT_INTERRUPT);
+        self.set_offset(8, func as usize);
+    }
 }

arch/x86_64/src/interrupt.rs

@@ -1,118 +0,0 @@
-//! Interrupt instructions
-
-/// Clear interrupts
-#[inline(always)]
-pub unsafe fn disable() {
-    asm!("cli" : : : : "intel", "volatile");
-}
-
-/// Set interrupts
-#[inline(always)]
-pub unsafe fn enable() {
-    asm!("sti" : : : : "intel", "volatile");
-}
-
-/// Set interrupts and halt
-#[inline(always)]
-pub unsafe fn enable_and_halt() {
-    asm!("sti
-        hlt"
-        : : : : "intel", "volatile");
-}
-
-/// Halt instruction
-#[inline(always)]
-pub unsafe fn halt() {
-    asm!("hlt" : : : : "intel", "volatile");
-}
-
-/// Pause instruction
-/// Safe because it is similar to a NOP, and has no memory effects
-#[inline(always)]
-pub fn pause() {
-    unsafe { asm!("pause" : : : : "intel", "volatile"); }
-}
-
-/// Get a stack trace
-//TODO: Check for stack being mapped before dereferencing
-#[inline(never)]
-pub unsafe fn stack_trace() {
-    let mut rbp: usize;
-    asm!("xchg bx, bx" : "={rbp}"(rbp) : : : "intel", "volatile");
-
-    println!("TRACE: {:>016X}", rbp);
-    //Maximum 64 frames
-    for _frame in 0..64 {
-        let rip = *(rbp as *const usize).offset(1);
-        println!("  {:>016X}: {:>016X}", rbp, rip);
-        if rip == 0 {
-            break;
-        }
-        rbp = *(rbp as *const usize);
-    }
-}
-
-/// x86 External Interrupts (1-16).
-pub static EXCEPTIONS: [Descriptor; 21] = [
-    Descriptor::new("Division error", Kind::Fault),
-    Descriptor::new("Debug trap", Kind::Trap),
-    Descriptor::new("Unmaskable interrupt", Kind::Unmaskable),
-    Descriptor::new("Breakpoint", Kind::Trap),
-    Descriptor::new("Overflow", Kind::Trap),
-    Descriptor::new("Out of bound", Kind::Fault),
-    Descriptor::new("Invalid opcode", Kind::Fault),
-    Descriptor::new("Device unavailable", Kind::Fault),
-    Descriptor::new("Double fault", Kind::Fault),
-    Descriptor::new("Coprocessor segment overrun", Kind::Fault),
-    Descriptor::new("Invalid TSS", Kind::Fault),
-    Descriptor::new("Segment not present", Kind::Fault),
-    Descriptor::new("Stack-segment fault", Kind::Fault),
-    Descriptor::new("General protection", Kind::Fault),
-    Descriptor::new("Page fault", Kind::Fault),
-    Descriptor::new("Reserved", Kind::Reserved),
-    Descriptor::new("x87 FPU", Kind::Fault),
-    Descriptor::new("Unaligned memory access", Kind::Fault),
-    Descriptor::new("Machine check", Kind::Abort),
-    Descriptor::new("SIMD floating-point", Kind::Fault),
-    Descriptor::new("Virtualization violation", Kind::Fault),
-];
-
-/// An interrupt description.
-#[derive(Debug, Copy, Clone)]
-pub struct Descriptor {
-    /// The description of this interrupt.
-    pub desc: &'static str,
-    /// The interrupt type.
-    pub kind: Kind,
-}
-
-impl Descriptor {
-    /// Create a new interrupt description.
-    pub const fn new(desc: &'static str, kind: Kind) -> Descriptor {
-        Descriptor {
-            desc: desc,
-            kind: kind,
-        }
-    }
-}
-
-/// The interrupt kind.
-#[derive(Debug, Copy, Clone)]
-pub enum Kind {
-    /// A fault.
-    ///
-    /// This can have multiple sources, but is often a result of a program error of some sort.
-    Fault,
-    /// A trap.
-    ///
-    /// These are often for debugging purposes.
-    Trap,
-    /// A deliberate abort.
-    Abort,
-    /// An unmaskable interrupt.
-    ///
-    /// This is a forced interrupt which need to be handled immediately.
-    Unmaskable,
-    /// Reserved or deprecated.
-    Reserved,
-}

arch/x86_64/src/interrupt/exception.rs

@@ -0,0 +1,97 @@
+use super::halt;
+
+interrupt!(divide_by_zero, {
+    print!("Divide by zero fault\n");
+    loop { halt(); }
+});
+
+interrupt!(debug, {
+    print!("Debug trap\n");
+});
+
+interrupt!(non_maskable, {
+    print!("Non-maskable interrupt\n");
+});
+
+interrupt!(breakpoint, {
+    print!("Breakpoint trap\n");
+});
+
+interrupt!(overflow, {
+    print!("Overflow trap\n");
+});
+
+interrupt!(bound_range, {
+    print!("Bound range exceeded fault\n");
+    loop { halt(); }
+});
+
+interrupt!(invalid_opcode, {
+    print!("Invalid opcode fault\n");
+    loop { halt(); }
+});
+
+interrupt!(device_not_available, {
+    print!("Device not available fault\n");
+    loop { halt(); }
+});
+
+interrupt_error!(double_fault, {
+    print!("Double fault\n");
+    loop { halt(); }
+});
+
+interrupt_error!(invalid_tss, {
+    print!("Invalid TSS fault\n");
+    loop { halt(); }
+});
+
+interrupt_error!(segment_not_present, {
+    print!("Segment not present fault\n");
+    loop { halt(); }
+});
+
+interrupt_error!(stack_segment, {
+    print!("Stack segment fault\n");
+    loop { halt(); }
+});
+
+interrupt_error!(protection, {
+    print!("Protection fault\n");
+    loop { halt(); }
+});
+
+interrupt_error!(page, {
+    print!("Page fault\n");
+    loop { halt(); }
+});
+
+interrupt!(fpu, {
+    print!("FPU floating point fault\n");
+    loop { halt(); }
+});
+
+interrupt_error!(alignment_check, {
+    print!("Alignment check fault\n");
+    loop { halt(); }
+});
+
+interrupt!(machine_check, {
+    print!("Machine check fault\n");
+    loop { halt(); }
+});
+
+interrupt!(simd, {
+    print!("SIMD floating point fault\n");
+    loop { halt(); }
+});
+
+interrupt!(virtualization, {
+    print!("Virtualization fault\n");
+    loop { halt(); }
+});
+
+interrupt_error!(security, {
+    print!("Security exception\n");
+    loop { halt(); }
+});

arch/x86_64/src/interrupt/irq.rs

@@ -0,0 +1,98 @@
+use x86::io;
+
+#[inline(always)]
+unsafe fn master_ack() {
+    io::outb(0x20, 0x20);
+}
+
+#[inline(always)]
+unsafe fn slave_ack() {
+    io::outb(0xA0, 0x20);
+    master_ack();
+}
+
+interrupt!(pit, {
+    io::outb(0x43, 0);
+    let low = io::inb(0x40);
+    let high = io::inb(0x40);
+    let count = (high as u16) << 8 | (low as u16);
+    let missed = 5370 - count;
+    master_ack();
+});
+
+interrupt!(keyboard, {
+    let data = io::inb(0x60);
+    print!("KEYBOARD {:X}\n", data);
+    master_ack();
+});
+
+interrupt!(cascade, {
+    print!("CASCADE\n");
+    master_ack();
+});
+
+interrupt!(com2, {
+    print!("COM2\n");
+    master_ack();
+});
+
+interrupt!(com1, {
+    print!("COM1\n");
+    master_ack();
+});
+
+interrupt!(lpt2, {
+    print!("LPT2\n");
+    master_ack();
+});
+
+interrupt!(floppy, {
+    print!("FLOPPY\n");
+    master_ack();
+});
+
+interrupt!(lpt1, {
+    print!("LPT1\n");
+    master_ack();
+});
+
+interrupt!(rtc, {
+    print!("RTC\n");
+    slave_ack();
+});
+
+interrupt!(pci1, {
+    print!("PCI1\n");
+    slave_ack();
+});
+
+interrupt!(pci2, {
+    print!("PCI2\n");
+    slave_ack();
+});
+
+interrupt!(pci3, {
+    print!("PCI3\n");
+    slave_ack();
+});
+
+interrupt!(mouse, {
+    let data = io::inb(0x60);
+    print!("MOUSE {:X}\n", data);
+    slave_ack();
+});
+
+interrupt!(fpu, {
+    print!("FPU\n");
+    slave_ack();
+});
+
+interrupt!(ata1, {
+    print!("ATA1\n");
+    slave_ack();
+});
+
+interrupt!(ata2, {
+    print!("ATA2\n");
+    slave_ack();
+});

arch/x86_64/src/interrupt/mod.rs

@@ -0,0 +1,57 @@
+//! Interrupt instructions
+
+pub mod exception;
+pub mod irq;
+pub mod syscall;
+
+/// Clear interrupts
+#[inline(always)]
+pub unsafe fn disable() {
+    asm!("cli" : : : : "intel", "volatile");
+}
+
+/// Set interrupts
+#[inline(always)]
+pub unsafe fn enable() {
+    asm!("sti" : : : : "intel", "volatile");
+}
+
+/// Set interrupts and halt
+#[inline(always)]
+pub unsafe fn enable_and_halt() {
+    asm!("sti
+        hlt"
+        : : : : "intel", "volatile");
+}
+
+/// Halt instruction
+#[inline(always)]
+pub unsafe fn halt() {
+    asm!("hlt" : : : : "intel", "volatile");
+}
+
+/// Pause instruction
+/// Safe because it is similar to a NOP, and has no memory effects
+#[inline(always)]
+pub fn pause() {
+    unsafe { asm!("pause" : : : : "intel", "volatile"); }
+}
+
+/// Get a stack trace
+//TODO: Check for stack being mapped before dereferencing
+#[inline(never)]
+pub unsafe fn stack_trace() {
+    let mut rbp: usize;
+    asm!("xchg bx, bx" : "={rbp}"(rbp) : : : "intel", "volatile");
+
+    println!("TRACE: {:>016X}", rbp);
+    //Maximum 64 frames
+    for _frame in 0..64 {
+        let rip = *(rbp as *const usize).offset(1);
+        println!("  {:>016X}: {:>016X}", rbp, rip);
+        if rip == 0 {
+            break;
+        }
+        rbp = *(rbp as *const usize);
+    }
+}

arch/x86_64/src/interrupt/syscall.rs

@@ -0,0 +1,22 @@
+#[naked]
+pub unsafe extern fn syscall() {
+    extern {
+        fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize) -> usize;
+    }
+
+    let a;
+    let b;
+    let c;
+    let d;
+    let e;
+    let f;
+    asm!("" : "={rax}"(a), "={rbx}"(b), "={rcx}"(c), "={rdx}"(d), "={rsi}"(e), "={rdi}"(f)
+        : : : "intel", "volatile");
+
+    let a = syscall(a, b, c, d, e, f);
+
+    asm!("" : : "{rax}"(a) : : "intel", "volatile");
+
+    // Pop scratch registers, error code, and return
+    asm!("iretq" : : : : "intel", "volatile");
+}

arch/x86_64/src/io/io.rs

@@ -7,10 +7,12 @@ pub trait Io {
     fn read(&self) -> Self::Value;
     fn write(&mut self, value: Self::Value);
 
+    #[inline(always)]
     fn readf(&self, flags: Self::Value) -> bool  {
         (self.read() & flags) as Self::Value == flags
     }
 
+    #[inline(always)]
     fn writef(&mut self, flags: Self::Value, value: bool) {
         let tmp: Self::Value = match value {
             true => self.read() | flags,
@@ -25,16 +27,18 @@ pub struct ReadOnly<I: Io> {
 }
 
 impl<I: Io> ReadOnly<I> {
-    pub fn new(inner: I) -> ReadOnly<I> {
+    pub const fn new(inner: I) -> ReadOnly<I> {
         ReadOnly {
             inner: inner
         }
     }
 
+    #[inline(always)]
     pub fn read(&self) -> I::Value {
         self.inner.read()
     }
 
+    #[inline(always)]
     pub fn readf(&self, flags: I::Value) -> bool {
         self.inner.readf(flags)
     }
@@ -45,16 +49,18 @@ pub struct WriteOnly<I: Io> {
 }
 
 impl<I: Io> WriteOnly<I> {
-    pub fn new(inner: I) -> WriteOnly<I> {
+    pub const fn new(inner: I) -> WriteOnly<I> {
         WriteOnly {
             inner: inner
         }
     }
 
+    #[inline(always)]
     pub fn write(&mut self, value: I::Value) {
         self.inner.write(value)
     }
 
+    #[inline(always)]
     pub fn writef(&mut self, flags: I::Value, value: bool) {
         self.inner.writef(flags, value)
     }

arch/x86_64/src/io/pio.rs

@@ -1,4 +1,5 @@
 use core::marker::PhantomData;
+use x86::io;
 
 use super::io::Io;
 
@@ -24,19 +25,15 @@ impl Io for Pio<u8> {
     type Value = u8;
 
     /// Read
+    #[inline(always)]
     fn read(&self) -> u8 {
-        let value: u8;
-        unsafe {
-            asm!("in $0, $1" : "={al}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
-        }
-        value
+        unsafe { io::inb(self.port) }
     }
 
     /// Write
+    #[inline(always)]
     fn write(&mut self, value: u8) {
-        unsafe {
-            asm!("out $1, $0" : : "{al}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
-        }
+        unsafe { io::outb(self.port, value) }
     }
 }
 
@@ -45,19 +42,15 @@ impl Io for Pio<u16> {
     type Value = u16;
 
     /// Read
+    #[inline(always)]
     fn read(&self) -> u16 {
-        let value: u16;
-        unsafe {
-            asm!("in $0, $1" : "={ax}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
-        }
-        value
+        unsafe { io::inw(self.port) }
     }
 
     /// Write
+    #[inline(always)]
     fn write(&mut self, value: u16) {
-        unsafe {
-            asm!("out $1, $0" : : "{ax}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
-        }
+        unsafe { io::outw(self.port, value) }
     }
 }
 
@@ -66,18 +59,14 @@ impl Io for Pio<u32> {
     type Value = u32;
 
     /// Read
+    #[inline(always)]
     fn read(&self) -> u32 {
-        let value: u32;
-        unsafe {
-            asm!("in $0, $1" : "={eax}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
-        }
-        value
+        unsafe { io::inl(self.port) }
     }
 
     /// Write
+    #[inline(always)]
     fn write(&mut self, value: u32) {
-        unsafe {
-            asm!("out $1, $0" : : "{eax}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
-        }
+        unsafe { io::outl(self.port, value) }
     }
 }

arch/x86_64/src/lib.rs

@@ -124,8 +124,8 @@ pub mod acpi;
 /// Context switching
 pub mod context;
 
-/// Display handling
-pub mod display;
+/// Devices
+pub mod device;
 
 /// Memcpy, memmove, etc.
 pub mod externs;

arch/x86_64/src/start.rs

@@ -7,7 +7,7 @@ use core::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, AtomicUsize, ATOMIC_USIZE
 
 use acpi;
 use allocator::{HEAP_START, HEAP_SIZE};
-use display;
+use device;
 use externs::memset;
 use gdt;
 use idt;
@@ -92,8 +92,8 @@ pub unsafe extern fn kstart() -> ! {
             assert_eq!(TDATA_TEST_NONZERO, 0xFFFFFFFFFFFFFFFE);
         }
 
-        // Initialize display
-        display::init(&mut active_table);
+        // Initialize devices
+        device::init(&mut active_table);
 
         // Reset AP variables
         AP_COUNT.store(0, Ordering::SeqCst);

kernel/context/mod.rs

@@ -151,13 +151,11 @@ pub unsafe fn switch() {
         return;
     }
 
-    unsafe {
     (&mut *from_ptr).running = false;
     (&mut *to_ptr).running = true;
     CONTEXT_ID.store((&mut *to_ptr).id, Ordering::SeqCst);
 
     (&mut *from_ptr).arch.switch_to(&mut (&mut *to_ptr).arch);
-    }
 }
 
 /// A context, which identifies either a process or a thread