kernel: Make the MBR code read from a device instead of an inode

Since ff952cfe16 made /dev mounted from userspace, /dev/cdrom does not exist when ATA drives are scanned.

.vscode/settings.json

@@ -13,5 +13,16 @@
     "files.trimFinalNewlines": true,
     "files.insertFinalNewline": true,
     "git.inputValidationLength": 72,
-    "git.inputValidationSubjectLength": 72
+    "git.inputValidationSubjectLength": 72,
+    "doxdocgen.file.fileOrder": [
+        "file",
+        "author",
+        "brief",
+        "empty",
+        "copyright",
+        "empty"
+    ],
+    "doxdocgen.file.copyrightTag": [
+        "@copyright Copyright (c) {year}, the Luna authors."
+    ]
 }

apps/init.cpp

@@ -14,7 +14,6 @@
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/sysmacros.h>
-#include <sys/wait.h>
 #include <unistd.h>
 
 FILE* g_init_log;
@@ -97,8 +96,7 @@ static Result<void> try_start_service(Service& service)
         fprintf(g_init_log, "[init] waiting for child process %d to finish\n", pid);
 
         int status;
-        pid_t id = waitpid(pid, &status, 0);
-        if (id < 0) { return err(errno); }
+        TRY(os::Process::wait(pid, &status));
 
         fprintf(g_init_log, "[init] child process %d exited with code %d\n", pid, WEXITSTATUS(status));
     }
@@ -312,7 +310,10 @@ int main()
     while (1)
     {
         int status;
-        pid_t child = wait(&status);
+        auto rc = os::Process::wait(os::Process::ANY_CHILD, &status);
+        if (rc.has_error()) continue;
+
+        pid_t child = rc.release_value();
 
         for (auto& service : g_services)
         {

apps/sh.cpp

@@ -11,7 +11,6 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/utsname.h>
-#include <sys/wait.h>
 #include <unistd.h>
 
 using os::File;
@@ -118,11 +117,7 @@ Result<int> luna_main(int argc, char** argv)
 
         if (child == 0) { TRY(execute_command(cmd.view())); }
 
-        if (waitpid(child, NULL, 0) < 0)
-        {
-            perror("waitpid");
-            return 1;
-        }
+        TRY(os::Process::wait(child, nullptr));
     }
 
     return 0;

apps/time.cpp

@@ -3,7 +3,6 @@
 #include <os/Process.h>
 #include <stdio.h>
 #include <sys/resource.h>
-#include <sys/wait.h>
 
 Result<int> luna_main(int argc, char** argv)
 {
@@ -23,11 +22,7 @@ Result<int> luna_main(int argc, char** argv)
         unreachable();
     }
 
-    if (waitpid(pid, nullptr, 0) < 0)
-    {
-        perror("waitpid");
-        return 1;
-    }
+    TRY(os::Process::wait(pid, nullptr));
 
     struct rusage usage;
     if (getrusage(RUSAGE_CHILDREN, &usage) < 0)

kernel/CMakeLists.txt

@@ -43,6 +43,7 @@ set(SOURCES
     src/fs/VFS.cpp
     src/fs/Pipe.cpp
     src/fs/Mount.cpp
+    src/fs/MBR.cpp
     src/fs/tmpfs/FileSystem.cpp
     src/fs/devices/DeviceRegistry.cpp
     src/fs/devices/NullDevice.cpp
@@ -65,6 +66,7 @@ if("${LUNA_ARCH}" MATCHES "x86_64")
         src/arch/x86_64/Thread.cpp
         src/arch/x86_64/PCI.cpp
         src/arch/x86_64/Keyboard.cpp
+        src/arch/x86_64/disk/ATA.cpp
         src/arch/x86_64/init/GDT.cpp
         src/arch/x86_64/init/IDT.cpp
         src/arch/x86_64/init/PIC.cpp

kernel/src/arch/CPU.h

@@ -22,6 +22,9 @@ namespace CPU
     void disable_interrupts();
     void wait_for_interrupt();
 
+    bool save_interrupts();
+    void restore_interrupts(bool saved);
+
     void get_stack_trace(void (*callback)(u64, void*), void* arg);
     void print_stack_trace();
     void get_stack_trace_at(Registers* regs, void (*callback)(u64, void*), void* arg);
@@ -29,5 +32,8 @@ namespace CPU
 
     u16 get_processor_id();
 
+    bool register_interrupt(u8 interrupt, void (*handler)(Registers*, void*), void* context);
+    void sync_interrupts();
+
     void pause();
 }

kernel/src/arch/PCI.cpp

@@ -9,6 +9,10 @@ struct ScanInfo
 
 namespace PCI
 {
+    BAR::BAR(u32 raw) : m_raw(raw)
+    {
+    }
+
     Device::ID read_id(const Device::Address& address)
     {
         const u16 vendor = read16(address, Field::VendorID);
@@ -108,4 +112,13 @@ namespace PCI
             }
         }
     }
+
+    BAR Device::getBAR(u8 index) const
+    {
+        check(index < 6);
+
+        u32 raw = read32(address, 0x10 + (index * 4));
+
+        return { raw };
+    }
 }

kernel/src/arch/PCI.h

@@ -17,7 +17,67 @@ namespace PCI
 
         HeaderType = 0x0e,
 
-        SecondaryBus = 0x19
+        BAR0 = 0x10,
+        BAR1 = 0x14,
+        BAR2 = 0x18,
+        BAR3 = 0x1c,
+
+        SecondaryBus = 0x19,
+
+        InterruptLine = 0x3c,
+    };
+
+    enum CommandField : u16
+    {
+        CMD_IO_SPACE = 1 << 0,
+        CMD_MEMORY_SPACE = 1 << 1,
+        CMD_BUS_MASTER = 1 << 2,
+        CMD_SPECIAL_CYCLES = 1 << 3,
+        CMD_MEMORY_WRITE_AND_INVALIDATE = 1 << 4,
+        CMD_VGA_PALETTE_SNOOP = 1 << 5,
+        CMD_PARITY_ERROR_RESPONSE = 1 << 6,
+        CMD_SERR = 1 << 8,
+        CMD_FAST_BACK_TO_BACK = 1 << 9,
+        CMD_INTERRUPT_DISABLE = 1 << 10,
+    };
+
+    struct BAR
+    {
+      public:
+        BAR(u32 raw);
+
+        bool is_iospace()
+        {
+            return m_raw & 0x01;
+        }
+
+        bool is_memory_space()
+        {
+            return !is_iospace();
+        }
+
+        u16 port()
+        {
+            return (u16)(m_raw & 0xfffffffc);
+        }
+
+        u8 type()
+        {
+            return (m_raw >> 1) & 0x03;
+        }
+
+        bool is_prefetchable()
+        {
+            return m_raw & (1 << 3);
+        }
+
+        u32 address_32bit()
+        {
+            return m_raw & 0xFFFFFFF0;
+        }
+
+      private:
+        u32 m_raw;
     };
 
     struct Device
@@ -42,6 +102,8 @@ namespace PCI
             u32 function;
         };
 
+        BAR getBAR(u8 index) const;
+
         ID id;
         Type type;
         Address address;

kernel/src/arch/x86_64/CPU.asm

@@ -188,4 +188,18 @@ ISR_ERROR 21 ; control-protection exception (#CP)
 ; ISR 22-31 reserved
 IRQ 32, 0 ; timer interrupt
 IRQ 33, 1 ; keyboard interrupt
+IRQ 34, 2
+IRQ 35, 3
+IRQ 36, 4
+IRQ 37, 5
+IRQ 38, 6
+IRQ 39, 7
+IRQ 40, 8
+IRQ 41, 9
+IRQ 42, 10
+IRQ 43, 11
+IRQ 44, 12
+IRQ 45, 13
+IRQ 46, 14
+IRQ 47, 15
 ISR 66 ; system call

kernel/src/arch/x86_64/CPU.cpp

@@ -22,12 +22,23 @@ extern "C" void enable_nx();
 
 extern void setup_gdt();
 extern void remap_pic();
+extern void change_pic_masks(u8 pic1_mask, u8 pic2_mask);
 extern void pic_eoi(unsigned char irq);
 extern void pic_eoi(Registers* regs);
 extern void setup_idt();
 
 static Thread* g_io_thread;
 
+typedef void (*interrupt_handler_t)(Registers*, void*);
+
+struct InterruptHandler
+{
+    interrupt_handler_t function;
+    void* context;
+};
+
+static InterruptHandler irq_handlers[16];
+
 void FPData::save()
 {
     asm volatile("fxsave (%0)" : : "r"(m_data));
@@ -150,21 +161,34 @@ void io_thread()
     }
 }
 
-// Called from _asm_interrupt_entry
-extern "C" void arch_interrupt_entry(Registers* regs)
-{
-    if (regs->isr < 32) handle_x86_exception(regs);
-    else if (regs->isr == 32) // Timer interrupt
+static void timer_interrupt(Registers* regs, void*)
 {
     Timer::tick();
     if (should_invoke_scheduler()) Scheduler::invoke(regs);
-        pic_eoi(regs);
 }
-    else if (regs->isr == 33) // Keyboard interrupt
+
+static void keyboard_interrupt(Registers*, void*)
 {
     u8 scancode = IO::inb(0x60);
     scancode_queue.try_push(scancode);
     g_io_thread->wake_up();
+}
+
+// Called from _asm_interrupt_entry
+extern "C" void arch_interrupt_entry(Registers* regs)
+{
+    if (regs->isr < 32) handle_x86_exception(regs);
+    else if (regs->isr >= 32 && regs->isr < 48) // IRQ from the PIC
+    {
+        u64 irq = regs->irq;
+        auto handler = irq_handlers[irq];
+        if (!handler.function)
+        {
+            kwarnln("Unhandled IRQ catched! Halting.");
+            CPU::efficient_halt();
+        }
+
+        handler.function(regs, handler.context);
         pic_eoi(regs);
     }
     else if (regs->isr == 66) // System call
@@ -174,7 +198,7 @@ extern "C" void arch_interrupt_entry(Registers* regs)
     }
     else
     {
-        kwarnln("IRQ catched! Halting.");
+        kwarnln("Unhandled interrupt catched! Halting.");
         CPU::efficient_halt();
     }
 }
@@ -233,6 +257,10 @@ namespace CPU
             kwarnln("not setting the NX bit as it is unsupported");
         setup_gdt();
         setup_idt();
+
+        memset(irq_handlers, 0, sizeof(irq_handlers));
+        register_interrupt(0, timer_interrupt, nullptr);
+        register_interrupt(1, keyboard_interrupt, nullptr);
     }
 
     void platform_finish_init()
@@ -241,6 +269,8 @@ namespace CPU
                           .expect_value("Could not create the IO background thread!");
 
         remap_pic();
+
+        sync_interrupts();
     }
 
     void enable_interrupts()
@@ -253,6 +283,20 @@ namespace CPU
         asm volatile("cli");
     }
 
+    bool save_interrupts()
+    {
+        u64 flags;
+        asm volatile("pushfq; pop %0" : "=r"(flags));
+        return flags & 0x200;
+    }
+
+    void restore_interrupts(bool saved)
+    {
+        if (saved) enable_interrupts();
+        else
+            disable_interrupts();
+    }
+
     void wait_for_interrupt()
     {
         asm volatile("hlt");
@@ -353,6 +397,35 @@ namespace CPU
         __get_cpuid(1, &unused, &ebx, &unused, &unused);
         return (u16)(ebx >> 24);
     }
+
+    bool register_interrupt(u8 interrupt, interrupt_handler_t handler, void* context)
+    {
+        if (irq_handlers[interrupt].function) return false;
+
+        irq_handlers[interrupt] = { handler, context };
+
+        sync_interrupts();
+
+        return true;
+    }
+
+    void sync_interrupts()
+    {
+        u8 pic1_mask, pic2_mask;
+        pic1_mask = pic2_mask = 0b11111111;
+        for (int i = 0; i < 8; i++)
+        {
+            if (irq_handlers[i].function) pic1_mask &= (u8)(~(1 << i));
+            if (irq_handlers[i + 8].function) pic2_mask &= (u8)(~(1 << i));
+        }
+
+        if (pic2_mask != 0b11111111) pic1_mask &= 0b11111011;
+
+        auto val = CPU::save_interrupts();
+        CPU::disable_interrupts();
+        change_pic_masks(pic1_mask, pic2_mask);
+        CPU::restore_interrupts(val);
+    }
 }
 
 // called by kernel_yield

kernel/src/arch/x86_64/CPU.h

@@ -5,7 +5,11 @@ struct Registers // Saved CPU registers for x86-64
 {
     u64 r15, r14, r13, r12, r11, r10, r9, r8;
     u64 rbp, rdi, rsi, rdx, rcx, rbx, rax;
-    u64 isr, error;
+    u64 isr;
+    union {
+        u64 error;
+        u64 irq;
+    };
     u64 rip, cs, rflags, rsp, ss;
 };
 

kernel/src/arch/x86_64/PCI.cpp

@@ -33,19 +33,32 @@ namespace PCI
 
     void write8(const Device::Address& address, u32 field, u8 value)
     {
-        ignore(address, field, value);
-        todo();
+        u8 offset = (u8)(field & ~0x3);
+        union {
+            u8 split[4];
+            u32 full;
+        };
+        full = read32(address, offset);
+        split[(field & 0x3)] = value;
+        write32(address, offset, full);
     }
 
-    void write16(const Device::Address& address, u32 field, u8 value)
+    void write16(const Device::Address& address, u32 field, u16 value)
     {
-        ignore(address, field, value);
-        todo();
+        u8 offset = (u8)(field & ~0x3);
+        union {
+            u8 split[4];
+            u32 full;
+        };
+        full = read32(address, offset);
+        split[(field & 0x3)] = (u8)(value >> 8);
+        split[(field & 0x3) + 1] = (u8)(value & 0xff);
+        write32(address, offset, full);
     }
 
-    void write32(const Device::Address& address, u32 field, u8 value)
+    void write32(const Device::Address& address, u32 field, u32 value)
     {
-        ignore(address, field, value);
-        todo();
+        IO::outl(PCI_ADDRESS_PORT, make_pci_address(address, field));
+        IO::outl(PCI_VALUE_PORT, value);
     }
 }

kernel/src/arch/x86_64/disk/ATA.cpp

@@ -0,0 +1,787 @@
+#include "arch/x86_64/disk/ATA.h"
+#include "Log.h"
+#include "arch/Serial.h"
+#include "arch/Timer.h"
+#include "arch/x86_64/IO.h"
+#include "fs/MBR.h"
+#include "memory/MemoryManager.h"
+#include <luna/Alignment.h>
+#include <luna/CType.h>
+#include <luna/SafeArithmetic.h>
+#include <luna/Vector.h>
+
+SharedPtr<ATA::Controller> g_controller;
+
+static void irq_handler(Registers* regs, void* ctx)
+{
+    ((ATA::Controller*)ctx)->irq_handler(regs);
+}
+
+static usize copy_ata_string(char* out, u16* in, usize size)
+{
+    for (usize i = 0; i < size; i += 2)
+    {
+        u16 val = in[i / 2];
+        out[i] = (u8)(val >> 8);
+        out[i + 1] = (u8)(val & 0xff);
+    }
+
+    out[size + 1] = '\0';
+
+    return size;
+}
+
+namespace ATA
+{
+    Result<void> Controller::scan()
+    {
+        // FIXME: Propagate errors.
+        PCI::scan(
+            [](const PCI::Device& device) {
+                if (!g_controller)
+                {
+                    auto controller = adopt_shared_if_nonnull(new (std::nothrow) Controller(device)).release_value();
+                    kinfoln("ata: Found ATA controller on PCI bus (%x:%x:%x)", device.address.bus,
+                            device.address.function, device.address.slot);
+
+                    if (controller->initialize()) g_controller = controller;
+                }
+            },
+            { .klass = 1, .subclass = 1 });
+
+        if (!g_controller) kwarnln("ata: No ATA controller found.");
+
+        return {};
+    }
+
+    bool Controller::initialize()
+    {
+        u16 command_old = PCI::read16(m_device.address, PCI::Command);
+        u16 command_new = command_old;
+
+        command_new &= ~PCI::CMD_INTERRUPT_DISABLE;
+        command_new |= PCI::CMD_IO_SPACE;
+        command_new |= PCI::CMD_BUS_MASTER;
+
+        if (command_new != command_old) PCI::write16(m_device.address, PCI::Command, command_new);
+
+        if (!m_primary_channel.initialize()) return false;
+
+        return m_secondary_channel.initialize();
+    }
+
+    void Controller::irq_handler(Registers* regs)
+    {
+        if (regs->irq == m_primary_channel.irq_line()) m_primary_channel.irq_handler(regs);
+        if (regs->irq == m_secondary_channel.irq_line()) m_secondary_channel.irq_handler(regs);
+    }
+
+    Controller::Controller(const PCI::Device& device)
+        : m_device(device), m_primary_channel(this, 0, {}), m_secondary_channel(this, 1, {})
+    {
+    }
+
+    Channel::Channel(Controller* controller, u8 channel_index, Badge<Controller>)
+        : m_controller(controller), m_channel_index(channel_index)
+    {
+    }
+
+    u8 Channel::read_register(Register reg)
+    {
+        return IO::inb(m_io_base + (u16)reg);
+    }
+
+    u16 Channel::read_data()
+    {
+        return IO::inw(m_io_base + (u16)Register::Data);
+    }
+
+    void Channel::write_data(u16 value)
+    {
+        IO::outw(m_io_base + (u16)Register::Data, value);
+    }
+
+    void Channel::write_register(Register reg, u8 value)
+    {
+        IO::outb(m_io_base + (u16)reg, value);
+    }
+
+    u8 Channel::read_control(ControlRegister reg)
+    {
+        return IO::inb(m_control_base + (u16)reg);
+    }
+
+    void Channel::write_control(ControlRegister reg, u8 value)
+    {
+        IO::outb(m_control_base + (u16)reg, value);
+    }
+
+    u8 Channel::read_bm(BusmasterRegister reg)
+    {
+        return IO::inb(m_busmaster_base + (u16)reg);
+    }
+
+    void Channel::write_bm(BusmasterRegister reg, u8 value)
+    {
+        IO::outb(m_busmaster_base + (u16)reg, value);
+    }
+
+    u32 Channel::read_prdt_address()
+    {
+        return IO::inl(m_busmaster_base + (u16)BusmasterRegister::PRDTAddress);
+    }
+
+    void Channel::write_prdt_address(u32 value)
+    {
+        IO::outl(m_busmaster_base + (u16)BusmasterRegister::PRDTAddress, value);
+    }
+
+    void Channel::delay_400ns()
+    {
+        // FIXME: We should use kernel_sleep(), but it doesn't support nanosecond granularity.
+        for (int i = 0; i < 14; i++) { [[maybe_unused]] volatile u8 val = read_control(ControlRegister::AltStatus); }
+    }
+
+    void Channel::select(u8 drive)
+    {
+        if (drive == m_current_drive) return;
+
+        u8 value = (drive << 4) | 0xa0;
+        write_register(Register::DriveSelect, value);
+
+        delay_400ns();
+
+        m_current_drive = drive;
+    }
+
+    void Channel::irq_handler(Registers*)
+    {
+        if (!(read_bm(BusmasterRegister::Status) & BMS_IRQPending)) return;
+
+        if (m_current_drive < 2 && m_drives[m_current_drive]) m_drives[m_current_drive]->irq_handler();
+
+        m_irq_called = true;
+
+        if (m_thread) m_thread->wake_up();
+    }
+
+    void Channel::prepare_for_irq()
+    {
+        m_thread = Scheduler::current();
+        m_irq_called = false;
+    }
+
+    void Channel::wait_for_irq()
+    {
+        if (!m_irq_called) kernel_wait_for_event();
+
+        m_irq_called = false;
+    }
+
+    bool Channel::wait_for_irq_or_timeout(u64 timeout)
+    {
+        if (!m_irq_called)
+        {
+            kernel_sleep(timeout);
+            m_irq_called = false;
+            return m_thread->sleep_ticks_left;
+        }
+
+        m_irq_called = false;
+        return true;
+    }
+
+    bool Channel::wait_for_reg_set(Register reg, u8 value, u64 timeout)
+    {
+        u64 begin = Timer::ticks_ms();
+        while (true)
+        {
+            u8 reg_value = reg == Register::Status ? read_control(ControlRegister::AltStatus) : read_register(reg);
+            if (reg_value & value) return true;
+            if ((Timer::ticks_ms() - begin) >= timeout) return false;
+            kernel_sleep(1);
+        }
+    }
+
+    bool Channel::wait_for_reg_clear(Register reg, u8 value, u64 timeout)
+    {
+        u64 begin = Timer::ticks_ms();
+        while (true)
+        {
+            u8 reg_value = reg == Register::Status ? read_control(ControlRegister::AltStatus) : read_register(reg);
+            if ((reg_value & value) == 0) return true;
+            if ((Timer::ticks_ms() - begin) >= timeout) return false;
+            kernel_sleep(1);
+        }
+    }
+
+    Result<void> Channel::wait_until_ready()
+    {
+        if (!wait_for_reg_clear(Register::Status, SR_Busy, 1000))
+        {
+            kwarnln("ata: Drive %d:%d timed out (BSY)", m_channel_index, m_current_drive);
+            return err(EIO);
+        }
+
+        if (!wait_for_reg_set(Register::Status, SR_DataRequestReady | SR_Error, 1000))
+        {
+            kwarnln("ata: Drive %d:%d timed out (DRQ)", m_channel_index, m_current_drive);
+            return err(EIO);
+        }
+
+        u8 status = read_control(ControlRegister::AltStatus);
+        if (status & SR_Error)
+        {
+            kwarnln("ata: An error occurred in drive %d:%d while waiting for data to become available", m_channel_index,
+                    m_current_drive);
+            return err(EIO);
+        }
+
+        return {};
+    }
+
+    bool Channel::initialize()
+    {
+        int offset = m_channel_index ? 2 : 0;
+        m_is_pci_native_mode = m_controller->device().type.prog_if & (1 << offset);
+
+        u16 control_port_base_address;
+        u16 io_base_address;
+
+        if (m_is_pci_native_mode)
+        {
+            auto io_base = m_controller->device().getBAR(m_channel_index ? 2 : 0);
+            if (!io_base.is_iospace())
+            {
+                kwarnln("ata: Channel %d's IO base BAR is not in IO space", m_channel_index);
+                return false;
+            }
+            io_base_address = io_base.port();
+
+            auto io_control = m_controller->device().getBAR(m_channel_index ? 3 : 1);
+            if (!io_control.is_iospace())
+            {
+                kwarnln("ata: Channel %d's control base BAR is not in IO space", m_channel_index);
+                return false;
+            }
+
+            control_port_base_address = io_control.port() + 2;
+        }
+        else
+        {
+            io_base_address = m_channel_index ? 0x170 : 0x1f0;
+            control_port_base_address = m_channel_index ? 0x376 : 0x3f6;
+        }
+
+        m_io_base = io_base_address;
+        m_control_base = control_port_base_address;
+
+        auto io_busmaster = m_controller->device().getBAR(4);
+        if (!io_busmaster.is_iospace())
+        {
+            kwarnln("ata: Channel %d's busmaster base BAR is not in IO space", m_channel_index);
+            return false;
+        }
+        m_busmaster_base = io_busmaster.port() + (u16)(m_channel_index * 8u);
+
+        if (m_is_pci_native_mode) m_interrupt_line = PCI::read8(m_controller->device().address, PCI::InterruptLine);
+        else
+            m_interrupt_line = m_channel_index ? 15 : 14;
+
+        write_control(ControlRegister::DeviceControl, 0);
+
+        for (u8 drive = 0; drive < 2; drive++)
+        {
+            ScopedKMutexLock<100> lock(m_lock);
+
+            select(drive);
+
+            if (read_register(Register::Status) == 0)
+            {
+                // No drive on this slot.
+                continue;
+            }
+
+            kinfoln("ata: Channel %d has a drive on slot %d!", m_channel_index, drive);
+
+            auto rc = adopt_shared_if_nonnull(new (std::nothrow) Drive(this, drive, {}));
+            if (rc.has_error())
+            {
+                kinfoln("ata: Failed to create drive object: %s", rc.error_string());
+                return false;
+            }
+
+            m_drives[drive] = rc.release_value();
+
+            if (!m_drives[drive]->initialize())
+            {
+                m_drives[drive] = {};
+                return false;
+            }
+        }
+
+        CPU::register_interrupt(m_interrupt_line, ::irq_handler, m_controller);
+
+        for (u8 drive = 0; drive < 2; drive++)
+        {
+            if (m_drives[drive])
+            {
+                if (!m_drives[drive]->post_initialize())
+                {
+                    m_drives[drive] = {};
+                    return false;
+                }
+
+                auto rc = ATADevice::create(m_drives[drive]);
+
+                if (rc.has_error())
+                {
+                    kwarnln("ata: Failed to register ATA drive %d:%d in DeviceRegistry", m_channel_index, drive);
+                    continue;
+                }
+
+                auto device = rc.release_value();
+                MBR::identify(device);
+            }
+        }
+
+        return true;
+    }
+
+    Drive::Drive(Channel* channel, u8 drive_index, Badge<Channel>) : m_channel(channel), m_drive_index(drive_index)
+    {
+    }
+
+    bool Drive::identify_ata()
+    {
+        m_channel->write_register(Register::Command, m_is_atapi ? CMD_Identify_Packet : CMD_Identify);
+
+        m_channel->delay_400ns();
+
+        if (!m_channel->wait_for_reg_clear(Register::Status, SR_Busy, 1000))
+        {
+            kwarnln("ata: Drive %d timed out clearing SR_Busy (waited for 1000 ms)", m_drive_index);
+            return false;
+        }
+
+        if (m_channel->read_register(Register::Status) & SR_Error)
+        {
+            u8 lbam = m_channel->read_register(Register::LBAMiddle);
+            u8 lbah = m_channel->read_register(Register::LBAHigh);
+
+            if ((lbam == 0x14 && lbah == 0xeb) || (lbam == 0x69 && lbah == 0x96))
+            {
+                if (!m_is_atapi)
+                {
+                    kinfoln("ata: Drive %d is ATAPI, sending IDENTIFY_PACKET command", m_drive_index);
+                    m_is_atapi = true;
+                    return identify_ata();
+                }
+            }
+
+            kwarnln("ata: IDENTIFY command for drive %d returned error", m_drive_index);
+
+            return false;
+        }
+
+        if (!m_channel->wait_for_reg_set(Register::Status, SR_DataRequestReady | SR_Error, 1000))
+        {
+            kwarnln("ata: Drive %d timed out setting SR_DataRequestReady (waited for 1000 ms)", m_drive_index);
+            return false;
+        }
+
+        u8 status = m_channel->read_register(Register::Status);
+        if (status & SR_Error)
+        {
+            kwarnln("ata: IDENTIFY command for drive %d returned error", m_drive_index);
+            return false;
+        }
+
+        for (usize i = 0; i < 256; i++)
+        {
+            u16 data = m_channel->read_data();
+            m_identify_words[i] = data;
+        }
+
+        return true;
+    }
+
+    bool Drive::initialize()
+    {
+        m_channel->select(m_drive_index);
+
+        m_channel->write_register(Register::SectorCount, 0);
+        m_channel->write_register(Register::LBALow, 0);
+        m_channel->write_register(Register::LBAMiddle, 0);
+        m_channel->write_register(Register::LBAHigh, 0);
+
+        if (!identify_ata()) return false;
+
+        m_serial.set_length(copy_ata_string(m_serial.data(), &m_identify_words[10], SERIAL_LEN));
+        m_revision.set_length(copy_ata_string(m_revision.data(), &m_identify_words[23], REVISION_LEN));
+        m_model.set_length(copy_ata_string(m_model.data(), &m_identify_words[27], MODEL_LEN));
+
+        m_serial.trim(" ");
+        m_revision.trim(" ");
+        m_model.trim(" ");
+
+        kinfoln("ata: Drive IDENTIFY returned serial='%s', revision='%s' and model='%s'", m_serial.chars(),
+                m_revision.chars(), m_model.chars());
+
+        auto status = m_channel->read_bm(BusmasterRegister::Status);
+        if (status & BMS_SimplexOnly)
+        {
+            kwarnln("ata: Drive %d will not use DMA because of simplex shenanigans", m_drive_index);
+            m_uses_dma = false;
+        }
+
+        auto frame = MemoryManager::alloc_frame();
+        if (frame.has_error() || frame.value() > 0xffffffff)
+        {
+            kwarnln("ata: Failed to allocate memory below the 32-bit limit for the PRDT");
+            return false;
+        }
+        m_dma_prdt_phys = frame.release_value();
+        m_dma_prdt = (prdt_entry*)MMU::translate_physical_address(m_dma_prdt_phys);
+
+        memset(m_dma_prdt, 0, ARCH_PAGE_SIZE);
+
+        frame = MemoryManager::alloc_frame();
+        if (frame.has_error() || frame.value() > 0xffffffff)
+        {
+            kwarnln("ata: Failed to allocate memory below the 32-bit limit for DMA memory");
+            return false;
+        }
+        m_dma_mem_phys = frame.release_value();
+        m_dma_mem = (void*)MMU::translate_physical_address(m_dma_mem_phys);
+
+        memset(const_cast<void*>(m_dma_mem), 0, ARCH_PAGE_SIZE);
+
+        if (m_uses_dma)
+        {
+            auto cmd = m_channel->read_bm(BusmasterRegister::Command);
+            cmd &= ~BMC_StartStop;
+            m_channel->write_bm(BusmasterRegister::Command, cmd);
+        }
+
+        return true;
+    }
+
+    bool Drive::post_initialize()
+    {
+        if (m_is_atapi)
+        {
+            atapi_packet packet;
+            memset(&packet, 0, sizeof(packet));
+            packet.command_bytes[0] = ATAPI_ReadCapacity;
+
+            atapi_read_capacity_reply reply;
+
+            if (send_packet_atapi_pio(&packet, &reply, sizeof(reply)).has_error())
+            {
+                kwarnln("ata: Failed to send Read Capacity command to ATAPI drive");
+                return false;
+            }
+
+            m_is_lba48 = true;
+
+            // FIXME: This assumes the host machine is little-endian.
+            u32 last_lba = __builtin_bswap32(reply.last_lba);
+            u32 sector_size = __builtin_bswap32(reply.sector_size);
+
+            m_block_count = last_lba + 1;
+            m_block_size = sector_size;
+        }
+        else
+        {
+            if (m_identify_data.big_lba) m_is_lba48 = true;
+
+            if (m_is_lba48) m_block_count = m_identify_data.sectors_48;
+            else
+                m_block_count = m_identify_data.sectors_28;
+
+            // FIXME: Should we check for CHS?
+
+            // FIXME: Maybe a different block size is in use? Detect that.
+            m_block_size = 512;
+        }
+
+        u64 total_capacity;
+        if (!safe_mul(m_block_count, m_block_size).try_set_value(total_capacity))
+        {
+            kwarnln("ata: Drive %d's total capacity is too large", m_drive_index);
+            return false;
+        }
+
+        kinfoln("ata: Drive %d capacity information: Block Count=%lu, Block Size=%lu, Total Capacity=%lu",
+                m_drive_index, m_block_count, m_block_size, total_capacity);
+
+        char buf[2048];
+        if (atapi_read_pio(0, buf, sizeof(buf)).has_error()) return false;
+
+        char readable[2049];
+        for (int i = 0; i < 2048; i++) { readable[i] = _iscntrl(buf[i]) ? '.' : buf[i]; }
+        readable[2048] = 0;
+        kinfoln("ata: Read first sector from CD-ROM: %s", readable);
+
+        return true;
+    }
+
+    Result<void> Drive::send_packet_atapi_pio(const atapi_packet* packet, void* out, u16 response_size)
+    {
+        u8* ptr = (u8*)out;
+
+        m_channel->select(m_drive_index);
+
+        // We use PIO here.
+        m_channel->write_register(Register::Features, 0x00);
+
+        m_channel->write_register(Register::LBAMiddle, (u8)(response_size & 0xff));
+        m_channel->write_register(Register::LBAHigh, (u8)(response_size >> 8));
+
+        m_channel->write_register(Register::Command, CMD_Packet);
+
+        m_channel->delay_400ns();
+
+        usize i = 0;
+
+        TRY(m_channel->wait_until_ready());
+
+        for (int j = 0; j < 6; j++) m_channel->write_data(packet->command_words[j]);
+
+        while (i < response_size)
+        {
+            TRY(m_channel->wait_until_ready());
+
+            usize byte_count =
+                m_channel->read_register(Register::LBAHigh) << 8 | m_channel->read_register(Register::LBAMiddle);
+            usize word_count = byte_count / 2;
+
+            while (word_count--)
+            {
+                u16 value = m_channel->read_data();
+                ptr[0] = (u8)(value & 0xff);
+                ptr[1] = (u8)(value >> 8);
+                ptr += 2;
+            }
+
+            i += byte_count;
+        }
+
+        return {};
+    }
+
+#if 0
+
+    Result<void> Drive::send_packet_atapi_dma(const atapi_packet* packet, void* out, u16 response_size)
+    {
+        check(m_uses_dma);
+
+        m_channel->select(m_drive_index);
+
+        kdbgln("have selected");
+
+        // We use DMA here.
+        m_channel->write_register(Register::Features, 0x01);
+
+        m_channel->write_register(Register::LBAMiddle, 0);
+        m_channel->write_register(Register::LBAHigh, 0);
+
+        kdbgln("will do_dma_command");
+
+        TRY(do_dma_command(CMD_Packet, response_size, false));
+
+        TRY(m_channel->wait_until_ready());
+
+        kdbgln("send atapi packet data");
+
+        for (int j = 0; j < 6; j++) m_channel->write_data(packet->command_words[j]);
+
+        kdbgln("do dma transfer");
+
+        TRY(do_dma_transfer());
+
+        memcpy(out, const_cast<void*>(m_dma_mem), response_size);
+
+        return {};
+    }
+
+    Result<void> Drive::do_dma_command(u8 command, u16 count, bool write)
+    {
+        m_dma_prdt->address = (u32)m_dma_mem_phys;
+        m_dma_prdt->count = count;
+        m_dma_prdt->flags = END_OF_PRDT;
+
+        kdbgln("ata: do_dma_command: phys=%x, command=%x, count=%u, write=%d", m_dma_prdt->address, command, count,
+               write);
+
+        m_channel->write_prdt_address((u32)m_dma_prdt_phys);
+
+        auto status = m_channel->read_bm(BusmasterRegister::Status);
+        status &= ~(BMS_DMAFailure | BMS_IRQPending);
+        m_channel->write_bm(BusmasterRegister::Status, status);
+
+        auto cmd = m_channel->read_bm(BusmasterRegister::Command);
+        if (!write) cmd |= BMC_ReadWrite;
+        else
+            cmd &= ~BMC_ReadWrite;
+        m_channel->write_bm(BusmasterRegister::Command, cmd);
+
+        m_channel->prepare_for_irq();
+
+        m_channel->write_register(Register::Command, command);
+
+        cmd = m_channel->read_bm(BusmasterRegister::Command);
+        cmd |= BMC_StartStop;
+        m_channel->write_bm(BusmasterRegister::Command, cmd);
+
+        m_channel->delay_400ns();
+
+        return {};
+    }
+
+    Result<void> Drive::do_dma_transfer()
+    {
+        if (!m_channel->wait_for_irq_or_timeout(2000))
+        {
+            kwarnln("ata: Drive %d timed out (DMA)", m_drive_index);
+            return err(EIO);
+        }
+
+        u8 status = m_channel->read_control(ControlRegister::AltStatus);
+        kdbgln("ata: status after irq: %#x", status);
+
+        m_channel->delay_400ns();
+
+        auto cmd = m_channel->read_bm(BusmasterRegister::Command);
+        cmd &= ~BMC_StartStop;
+        m_channel->write_bm(BusmasterRegister::Command, cmd);
+
+        status = m_channel->read_bm(BusmasterRegister::Status);
+        m_channel->write_bm(BusmasterRegister::Status, status & ~(BMS_DMAFailure | BMS_IRQPending));
+
+        if (status & BMS_DMAFailure)
+        {
+            kwarnln("ata: DMA failure while trying to read drive %d", m_drive_index);
+            return err(EIO);
+        }
+
+        return {};
+    }
+
+#endif
+
+    Result<void> Drive::atapi_read_pio(u64 lba, void* out, usize size)
+    {
+        check(lba < m_block_count);
+        check(size <= ARCH_PAGE_SIZE);
+
+        atapi_packet read_packet;
+        memset(&read_packet, 0, sizeof(read_packet));
+        read_packet.command_bytes[0] = ATAPI_Read;
+        read_packet.command_bytes[2] = (lba >> 0x18) & 0xff;
+        read_packet.command_bytes[3] = (lba >> 0x10) & 0xff;
+        read_packet.command_bytes[4] = (lba >> 0x08) & 0xff;
+        read_packet.command_bytes[5] = (lba >> 0x00) & 0xff;
+        read_packet.command_bytes[9] = (u8)(size / m_block_size);
+
+        return send_packet_atapi_pio(&read_packet, out, (u16)size);
+    }
+
+    Result<void> Drive::read_lba(u64 lba, void* out, usize nblocks)
+    {
+        const usize blocks_per_page = ARCH_PAGE_SIZE / m_block_size;
+        if (m_is_atapi)
+        {
+            kdbgln("ata: Reading %zu blocks from ATAPI drive using PIO, at LBA %ld", nblocks, lba);
+            while (nblocks > blocks_per_page)
+            {
+                TRY(atapi_read_pio(lba, out, ARCH_PAGE_SIZE));
+                lba += blocks_per_page;
+                nblocks -= blocks_per_page;
+                out = offset_ptr(out, ARCH_PAGE_SIZE);
+            }
+            return atapi_read_pio(lba, out, nblocks * m_block_size);
+        }
+        else
+            todo();
+    }
+
+    void Drive::irq_handler()
+    {
+        // Clear the IRQ flag.
+        u8 status = m_channel->read_register(Register::Status);
+
+        if (status & SR_Error)
+        {
+            u8 error = m_channel->read_register(Register::Error);
+            (void)error;
+        }
+
+        if (m_uses_dma)
+        {
+            status = m_channel->read_bm(BusmasterRegister::Status);
+            if (status & BMS_DMAFailure) { kwarnln("ata: DMA failure in irq"); }
+            m_channel->write_bm(BusmasterRegister::Status, 4);
+        }
+    }
+}
+
+static u32 next_minor = 0;
+
+Result<SharedPtr<Device>> ATADevice::create(SharedPtr<ATA::Drive> drive)
+{
+    auto device = TRY(adopt_shared_if_nonnull(new (std::nothrow) ATADevice()));
+    device->m_drive = drive;
+    TRY(DeviceRegistry::register_special_device(DeviceRegistry::Disk, next_minor++, device, "cdrom", 0400));
+    return (SharedPtr<Device>)device;
+}
+
+Result<u64> ATADevice::read(u8* buf, usize offset, usize size) const
+{
+    if (size == 0) return 0;
+
+    if (offset > m_drive->capacity()) return 0;
+    if (offset + size > m_drive->capacity()) size = m_drive->capacity() - offset;
+
+    usize length = size;
+
+    auto block_size = m_drive->block_size();
+
+    auto* temp = TRY(make_array<u8>(block_size));
+    auto guard = make_scope_guard([temp] { delete[] temp; });
+
+    if (offset % block_size)
+    {
+        usize extra_size = block_size - (offset % block_size);
+        TRY(m_drive->read_lba(offset / block_size, temp, 1));
+        memcpy(buf, temp + (offset % block_size), extra_size);
+        offset += extra_size;
+        size -= extra_size;
+        buf += extra_size;
+    }
+
+    while (size >= ARCH_PAGE_SIZE)
+    {
+        TRY(m_drive->read_lba(offset / block_size, buf, ARCH_PAGE_SIZE / block_size));
+        offset += ARCH_PAGE_SIZE;
+        size -= ARCH_PAGE_SIZE;
+        buf += ARCH_PAGE_SIZE;
+    }
+
+    while (size >= block_size)
+    {
+        TRY(m_drive->read_lba(offset / block_size, buf, 1));
+        offset += block_size;
+        size -= block_size;
+        buf += block_size;
+    }
+
+    if (size)
+    {
+        TRY(m_drive->read_lba(offset / block_size, temp, 1));
+        memcpy(buf, temp, size);
+    }
+
+    return length;
+}

kernel/src/arch/x86_64/disk/ATA.h

@@ -0,0 +1,321 @@
+#pragma once
+#include "arch/PCI.h"
+#include "fs/devices/DeviceRegistry.h"
+#include "lib/KMutex.h"
+#include <luna/Atomic.h>
+#include <luna/SharedPtr.h>
+#include <luna/StaticString.h>
+
+namespace ATA
+{
+    enum class Register : u16
+    {
+        Data = 0,
+        Error = 1,
+        Features = 1,
+        SectorCount = 2,
+        SectorNumber = 3,
+        LBALow = 3,
+        CylinderLow = 4,
+        LBAMiddle = 4,
+        CylinderHigh = 5,
+        LBAHigh = 5,
+        DriveSelect = 6,
+        Status = 7,
+        Command = 7,
+    };
+
+    enum class ControlRegister : u16
+    {
+        AltStatus = 0,
+        DeviceControl = 0,
+        DriveAddress = 1,
+    };
+
+    enum class BusmasterRegister : u16
+    {
+        Command = 0,
+        Status = 2,
+        PRDTAddress = 4,
+    };
+
+    enum StatusRegister : u8
+    {
+        SR_Busy = 0x80,
+        SR_DriveReady = 0x40,
+        SR_WriteFault = 0x20,
+        SR_SeekComplete = 0x10,
+        SR_DataRequestReady = 0x08,
+        SR_CorrectedData = 0x04,
+        SR_Index = 0x02,
+        SR_Error = 0x01
+    };
+
+    enum CommandRegister : u8
+    {
+        CMD_Identify = 0xec,
+        CMD_Packet = 0xa0,
+        CMD_Identify_Packet = 0xa1
+    };
+
+    enum BusMasterStatus : u8
+    {
+        BMS_SimplexOnly = 0x80,
+        BMS_SlaveInit = 0x40,
+        BMS_MasterInit = 0x20,
+        BMS_IRQPending = 0x4,
+        BMS_DMAFailure = 0x2,
+        BMS_DMAMode = 0x1
+    };
+
+    enum BusMasterCommand : u8
+    {
+        BMC_ReadWrite = 0x8,
+        BMC_StartStop = 0x1,
+    };
+
+    struct ATAIdentify
+    {
+        u16 flags;
+        u16 unused1[9];
+        char serial[20];
+        u16 unused2[3];
+        char firmware[8];
+        char model[40];
+        u16 sectors_per_int;
+        u16 unused3;
+        u16 capabilities[2];
+        u16 unused4[2];
+        u16 valid_ext_data;
+        u16 unused5[5];
+        u16 size_of_rw_mult;
+        u32 sectors_28;
+        u16 unused6[21];
+        u16 unused7 : 10;
+        u16 big_lba : 1;
+        u16 unused8 : 5;
+        u16 unused9[17];
+        u64 sectors_48;
+        u16 unused10[152];
+    };
+
+    enum ATAPICommand : u8
+    {
+        ATAPI_ReadCapacity = 0x25,
+        ATAPI_Read = 0xa8,
+    };
+
+    class Controller;
+    class Channel;
+
+    struct prdt_entry
+    {
+        u32 address;
+        u16 count;
+        u16 flags;
+    };
+
+    struct atapi_packet
+    {
+        union {
+            u16 command_words[6];
+            u8 command_bytes[12];
+        };
+    };
+
+    struct atapi_read_capacity_reply
+    {
+        u32 last_lba;
+        u32 sector_size;
+    };
+
+    static constexpr u16 END_OF_PRDT = (1 << 15);
+
+    class Drive
+    {
+      public:
+        Drive(Channel* channel, u8 drive_index, Badge<Channel>);
+
+        bool initialize();
+
+        bool post_initialize();
+
+        void irq_handler();
+
+        usize block_size() const
+        {
+            return m_block_size;
+        }
+
+        usize block_count() const
+        {
+            return m_block_count;
+        }
+
+        usize capacity() const
+        {
+            return m_block_count * m_block_size;
+        }
+
+        Result<void> read_lba(u64 lba, void* out, usize nblocks);
+
+      private:
+        bool identify_ata();
+
+        Result<void> send_packet_atapi_pio(const atapi_packet* packet, void* out, u16 response_size);
+#if 0
+        Result<void> send_packet_atapi_dma(const atapi_packet* packet, void* out, u16 response_size);
+
+        Result<void> do_dma_command(u8 command, u16 count, bool write);
+        Result<void> do_dma_transfer();
+#endif
+
+        Result<void> atapi_read_pio(u64 lba, void* out, usize size);
+
+        Channel* m_channel;
+
+        u8 m_drive_index;
+        union {
+            u16 m_identify_words[256];
+            ATAIdentify m_identify_data;
+        };
+
+        bool m_is_atapi { false };
+        bool m_uses_dma { true };
+
+        bool m_is_lba48;
+        u64 m_block_count;
+        u64 m_block_size;
+
+        prdt_entry* m_dma_prdt;
+        u64 m_dma_prdt_phys;
+        volatile void* m_dma_mem;
+        u64 m_dma_mem_phys;
+
+        constexpr static usize SERIAL_LEN = 20;
+        constexpr static usize REVISION_LEN = 8;
+        constexpr static usize MODEL_LEN = 40;
+
+        StaticString<SERIAL_LEN> m_serial;
+        StaticString<REVISION_LEN> m_revision;
+        StaticString<MODEL_LEN> m_model;
+    };
+
+    class Channel
+    {
+      public:
+        Channel(Controller* controller, u8 channel_index, Badge<Controller>);
+
+        u8 read_register(Register reg);
+        u16 read_data();
+        void write_data(u16 value);
+        void write_register(Register reg, u8 value);
+        u8 read_control(ControlRegister reg);
+        void write_control(ControlRegister reg, u8 value);
+
+        u8 read_bm(BusmasterRegister reg);
+        void write_bm(BusmasterRegister reg, u8 value);
+        u32 read_prdt_address();
+        void write_prdt_address(u32 value);
+
+        bool wait_for_reg_set(Register reg, u8 value, u64 timeout);
+        bool wait_for_reg_clear(Register reg, u8 value, u64 timeout);
+
+        Result<void> wait_until_ready();
+
+        void delay_400ns();
+
+        void prepare_for_irq();
+
+        void wait_for_irq();
+        bool wait_for_irq_or_timeout(u64 timeout);
+        void irq_handler(Registers*);
+
+        u8 irq_line()
+        {
+            return m_interrupt_line;
+        }
+
+        void select(u8 drive);
+
+        bool initialize();
+
+      private:
+        Controller* m_controller;
+        u8 m_channel_index;
+        bool m_is_pci_native_mode;
+
+        u8 m_interrupt_line;
+
+        KMutex<100> m_lock {};
+
+        Thread* m_thread { nullptr };
+
+        u16 m_io_base;
+        u16 m_control_base;
+        u16 m_busmaster_base;
+
+        bool m_irq_called { false };
+
+        u8 m_current_drive = (u8)-1;
+
+        SharedPtr<Drive> m_drives[2];
+    };
+
+    class Controller
+    {
+      public:
+        static Result<void> scan();
+
+        const PCI::Device& device() const
+        {
+            return m_device;
+        }
+
+        bool initialize();
+
+        void irq_handler(Registers*);
+
+      private:
+        Controller(const PCI::Device& device);
+        PCI::Device m_device;
+        Channel m_primary_channel;
+        Channel m_secondary_channel;
+    };
+
+}
+
+class ATADevice : public Device
+{
+  public:
+    // Initializer for DeviceRegistry.
+    static Result<void> create(SharedPtr<ATA::Drive> drive);
+
+    Result<usize> read(u8*, usize, usize) const override;
+
+    Result<usize> write(const u8*, usize, usize) override
+    {
+        return err(ENOTSUP);
+    }
+
+    bool blocking() const override
+    {
+        return false;
+    }
+
+    bool is_block_device() const override
+    {
+        return true;
+    }
+
+    usize size() const override
+    {
+        return m_drive->capacity();
+    }
+
+    virtual ~ATADevice() = default;
+
+  private:
+    ATADevice() = default;
+    SharedPtr<ATA::Drive> m_drive;
+};

kernel/src/arch/x86_64/init/IDT.cpp

@@ -84,6 +84,20 @@ INT(20);
 INT(21);
 INT(32);
 INT(33);
+INT(34);
+INT(35);
+INT(36);
+INT(37);
+INT(38);
+INT(39);
+INT(40);
+INT(41);
+INT(42);
+INT(43);
+INT(44);
+INT(45);
+INT(46);
+INT(47);
 INT(66);
 
 void setup_idt()
@@ -112,6 +126,20 @@ void setup_idt()
     TRAP(21);
     IRQ(32);
     IRQ(33);
+    IRQ(34);
+    IRQ(35);
+    IRQ(36);
+    IRQ(37);
+    IRQ(38);
+    IRQ(39);
+    IRQ(40);
+    IRQ(41);
+    IRQ(42);
+    IRQ(43);
+    IRQ(44);
+    IRQ(45);
+    IRQ(46);
+    IRQ(47);
     SYS(66);
 
     static IDTR idtr;

kernel/src/arch/x86_64/init/PIC.cpp

@@ -36,9 +36,18 @@ void remap_pic()
     IO::outb(PIC2_DATA, ICW4_8086);
     io_delay();
 
-    IO::outb(PIC1_DATA, 0b11111100);
+    IO::outb(PIC1_DATA, 0b11111111);
     io_delay();
     IO::outb(PIC2_DATA, 0b11111111);
+    io_delay();
+}
+
+void change_pic_masks(u8 pic1_mask, u8 pic2_mask)
+{
+    IO::outb(PIC1_DATA, pic1_mask);
+    io_delay();
+    IO::outb(PIC2_DATA, pic2_mask);
+    io_delay();
 }
 
 void pic_eoi(unsigned char irq)
@@ -49,5 +58,5 @@ void pic_eoi(unsigned char irq)
 
 void pic_eoi(Registers* regs)
 {
-    pic_eoi((unsigned char)(regs->error)); // On IRQs, the error code is the IRQ number
+    pic_eoi((unsigned char)(regs->irq));
 }

kernel/src/fs/MBR.cpp

@@ -0,0 +1,29 @@
+#include "fs/MBR.h"
+#include "Log.h"
+
+namespace MBR
+{
+    Result<bool> identify(SharedPtr<Device> device)
+    {
+        // Cannot read a partition table from a character device! Who is even coming up with this silliness?
+        if (!device->is_block_device()) return false;
+
+        DiskHeader hdr;
+        usize nread = TRY(device->read((u8*)&hdr, 0, sizeof(hdr)));
+        check(nread == 512);
+
+        if (hdr.signature[0] != MBR_SIGNATURE_1 || hdr.signature[1] != MBR_SIGNATURE_2) return false;
+
+        for (int i = 0; i < 4; i++)
+        {
+            const auto& part = hdr.partitions[i];
+            if (part.partition_type == 0) continue; // Not active.
+
+            bool bootable = part.attributes & MBR_BOOTABLE;
+            kinfoln("mbr: Partition #%d is active: bootable=%d, type=%x, start=%d, sectors=%d", i, bootable,
+                    part.partition_type, part.start_lba, part.num_sectors);
+        }
+
+        return true;
+    }
+}

kernel/src/fs/MBR.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include "fs/devices/DeviceRegistry.h"
+#include <luna/Types.h>
+
+#define MBR_BOOTABLE 0x80
+
+#define MBR_SIGNATURE_1 0x55
+#define MBR_SIGNATURE_2 0xAA
+
+namespace MBR
+{
+    struct [[gnu::packed]] PartitionHeader
+    {
+        u8 attributes;
+        u8 chs_start[3];
+        u8 partition_type;
+        u8 chs_end[3];
+        u32 start_lba;
+        u32 num_sectors;
+    };
+
+    struct [[gnu::packed]] DiskHeader
+    {
+        u8 mbr_code[440];
+        u8 disk_id[4];
+        u8 reserved[2];
+        PartitionHeader partitions[4];
+        u8 signature[2];
+    };
+
+    static_assert(sizeof(DiskHeader) == 512ul);
+
+    Result<bool> identify(SharedPtr<Device> device);
+};

kernel/src/fs/devices/DeviceRegistry.h

@@ -13,6 +13,7 @@ namespace DeviceRegistry
         Console = 1,
         Memory = 2,
         Framebuffer = 3,
+        Disk = 4,
     };
 
     Result<SharedPtr<Device>> fetch_special_device(u32 major, u32 minor);

kernel/src/lib/KMutex.h

@@ -0,0 +1,77 @@
+#pragma once
+#include "Log.h"
+#include "arch/CPU.h"
+#include "thread/Scheduler.h"
+#include "thread/Thread.h"
+#include <luna/CircularQueue.h>
+
+template <usize ConcurrentThreads> class KMutex
+{
+  public:
+    void lock()
+    {
+        int expected = 0;
+        while (!m_lock.compare_exchange_strong(expected, 1))
+        {
+            expected = 0;
+            auto* current = Scheduler::current();
+
+            // We cannot be interrupted between these functions, otherwise we might never exit the loop
+            CPU::disable_interrupts();
+            bool ok = m_blocked_threads.try_push(current);
+            if (!ok) kernel_sleep(10);
+            else
+                kernel_wait_for_event();
+            CPU::enable_interrupts();
+        }
+    };
+
+    void unlock()
+    {
+        int expected = 1;
+        if (!m_lock.compare_exchange_strong(expected, 0))
+        {
+            kwarnln("KMutex::unlock() called on an unlocked lock with value %d", expected);
+        }
+
+        Thread* blocked;
+        if (m_blocked_threads.try_pop(blocked)) blocked->wake_up();
+    }
+
+    bool try_lock()
+    {
+        int expected = 0;
+        return m_lock.compare_exchange_strong(expected, 1);
+    }
+
+  private:
+    CircularQueue<Thread*, ConcurrentThreads> m_blocked_threads;
+    Atomic<int> m_lock;
+};
+
+template <usize ConcurrentThreads> class ScopedKMutexLock
+{
+  public:
+    ScopedKMutexLock(KMutex<ConcurrentThreads>& lock) : m_lock(lock)
+    {
+        m_lock.lock();
+    }
+
+    ~ScopedKMutexLock()
+    {
+        if (!m_taken_over) m_lock.unlock();
+    }
+
+    ScopedKMutexLock(const ScopedKMutexLock&) = delete;
+    ScopedKMutexLock(ScopedKMutexLock&&) = delete;
+
+    KMutex<ConcurrentThreads>& take_over()
+    {
+        m_taken_over = true;
+        return m_lock;
+    }
+
+  private:
+    KMutex<ConcurrentThreads>& m_lock;
+    bool m_taken_over { false };
+};

kernel/src/main.cpp

@@ -1,6 +1,5 @@
 #include "Log.h"
 #include "arch/CPU.h"
-#include "arch/PCI.h"
 #include "arch/Timer.h"
 #include "boot/Init.h"
 #include "config.h"
@@ -11,6 +10,10 @@
 #include "thread/Scheduler.h"
 #include <luna/Units.h>
 
+#ifdef ARCH_X86_64
+#include "arch/x86_64/disk/ATA.h"
+#endif
+
 extern void set_host_name(StringView);
 
 void reap_thread()
@@ -53,12 +56,9 @@ Result<void> init()
     auto reap = Scheduler::new_kernel_thread(reap_thread, "[reap]").release_value();
     Scheduler::set_reap_thread(reap);
 
-    PCI::scan(
-        [](const PCI::Device& device) {
-            kinfoln("Found PCI mass storage device %.4x:%.4x, at address %u:%u:%u", device.id.vendor, device.id.device,
-                    device.address.bus, device.address.slot, device.address.function);
-        },
-        { .klass = 1 });
+#ifdef ARCH_X86_64
+    ATA::Controller::scan();
+#endif
 
     // Disable console logging before transferring control to userspace.
     setup_log(log_debug_enabled(), log_serial_enabled(), false);

libluna/CMakeLists.txt

@@ -25,6 +25,7 @@ set(FREESTANDING_SOURCES
     src/PathParser.cpp
     src/UBSAN.cpp
     src/Base64.cpp
+    src/Hash.cpp
 )
 
 set(SOURCES

libluna/include/luna/Hash.h

@@ -0,0 +1,29 @@
+#pragma once
+#include <luna/CString.h>
+#include <luna/Types.h>
+
+u64 hash_memory(const void* mem, usize size, u64 salt);
+
+template <typename T> u64 hash(const T& value, u64 salt)
+{
+    return hash_memory(&value, sizeof(value), salt);
+}
+
+template <> u64 hash(const char* const& value, u64 salt);
+
+template <typename T> static void swap(T* a, T* b)
+{
+    char* x = (char*)a;
+    char* y = (char*)b;
+
+    usize size = sizeof(T);
+
+    while (size--)
+    {
+        char t = *x;
+        *x = *y;
+        *y = t;
+        x += 1;
+        y += 1;
+    }
+}

libluna/include/luna/HashTable.h

@@ -0,0 +1,146 @@
+#pragma once
+#include <luna/Hash.h>
+#include <luna/Heap.h>
+#include <luna/Option.h>
+
+template <typename T> class HashTable
+{
+    static constexpr usize GROW_RATE = 2;
+    static constexpr usize GROW_FACTOR = 16;
+
+  public:
+    Result<bool> try_set(const T& value)
+    {
+        T copy { value };
+        return try_set(move(copy));
+    }
+
+    Result<bool> try_set(T&& value)
+    {
+        if (should_grow()) TRY(rehash(m_capacity + GROW_FACTOR));
+
+        u64 index = hash(value, m_salt) % m_capacity;
+
+        while (true)
+        {
+            auto& bucket = m_buckets[index];
+            if (bucket.has_value())
+            {
+                if (*bucket == value) return false;
+                index++;
+                continue;
+            }
+            bucket = { move(value) };
+            m_size++;
+            break;
+        }
+
+        return true;
+    }
+
+    T* try_find(const T& value)
+    {
+        if (!m_size) return nullptr;
+
+        check(m_capacity);
+
+        const u64 index = hash(value, m_salt) % m_capacity;
+        usize i = index;
+
+        do {
+            auto& bucket = m_buckets[index];
+            if (bucket.has_value())
+            {
+                if (*bucket == value) return bucket.value_ptr();
+                i++;
+            }
+            return nullptr;
+        } while (i != index);
+
+        return nullptr;
+    }
+
+    bool try_remove(const T& value)
+    {
+        if (!m_size) return false;
+
+        check(m_capacity);
+
+        const u64 index = hash(value, m_salt) % m_capacity;
+        usize i = index;
+
+        do {
+            auto& bucket = m_buckets[index];
+            if (bucket.has_value())
+            {
+                if (*bucket == value)
+                {
+                    bucket = {};
+                    m_size--;
+                    if (i != index) rehash(m_capacity);
+                    return true;
+                }
+                i++;
+            }
+            return false;
+        } while (i != index);
+
+        return false;
+    }
+
+    void clear()
+    {
+        for (usize i = 0; i < m_capacity; i++) m_buckets[i].~Option();
+
+        free_impl(m_buckets);
+        m_capacity = m_size = 0;
+    }
+
+    ~HashTable()
+    {
+        clear();
+    }
+
+  private:
+    bool should_grow()
+    {
+        return (m_capacity == 0) || ((m_size * GROW_RATE) >= m_capacity);
+    }
+
+    Result<void> rehash(usize new_capacity)
+    {
+        HashTable<T> new_table;
+        TRY(new_table.initialize(new_capacity));
+
+        if (m_capacity != 0)
+        {
+            for (usize i = 0; i < m_capacity; i++)
+            {
+                auto& opt = m_buckets[i];
+                if (opt.has_value())
+                {
+                    auto value = opt.release_value();
+                    TRY(new_table.try_set(move(value)));
+                }
+            }
+        }
+
+        swap(this, &new_table);
+
+        return {};
+    }
+
+    Result<void> initialize(usize initial_capacity)
+    {
+        check(m_buckets == nullptr);
+        m_capacity = initial_capacity;
+        m_buckets = (Option<T>*)TRY(calloc_impl(initial_capacity, sizeof(Option<T>), false));
+        return {};
+    }
+
+    Option<T>* m_buckets { nullptr };
+    usize m_capacity { 0 };
+    usize m_size { 0 };
+    // FIXME: Randomize this to protect against hash table attacks.
+    u64 m_salt { 0 };
+};

libluna/include/luna/StaticString.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <luna/CString.h>
+#include <luna/StringView.h>
 #include <luna/Types.h>
 
 template <usize Size> class StaticString
@@ -24,12 +25,27 @@ template <usize Size> class StaticString
             m_length = length;
     }
 
+    void adopt(StringView string)
+    {
+        usize length = strlcpy(m_buffer, string.chars(),
+                               string.length() > sizeof(m_buffer) ? sizeof(m_buffer) : string.length() + 1);
+        if (length > Size) { m_length = Size; }
+        else
+            m_length = length;
+    }
+
     StaticString<Size>& operator=(const char* string)
     {
         adopt(string);
         return *this;
     }
 
+    StaticString<Size>& operator=(StringView string)
+    {
+        adopt(string);
+        return *this;
+    }
+
     template <usize OtherSize> StaticString<Size>& operator=(const StaticString<OtherSize>& string)
     {
         if constexpr (OtherSize == Size)
@@ -46,11 +62,38 @@ template <usize Size> class StaticString
         return m_buffer;
     }
 
+    char* data()
+    {
+        return m_buffer;
+    }
+
+    void set_length(usize len)
+    {
+        m_length = len;
+    }
+
     usize length() const
     {
         return m_length;
     }
 
+    void trim(StringView delim)
+    {
+        isize i = (isize)m_length;
+
+        while (i--)
+        {
+            char c = m_buffer[i];
+            if (!strchr(delim.chars(), c)) break;
+        }
+
+        i++;
+
+        m_buffer[i] = '\0';
+
+        m_length = (usize)i;
+    }
+
   private:
     char m_buffer[Size + 1];
     usize m_length { 0 };

libluna/include/luna/Vector.h

@@ -15,12 +15,7 @@ template <typename T> class Vector
     {
     }
 
-    Vector(const Vector<T>& other)
-    {
-        reserve(other.capacity());
-        memcpy(m_data, other.data(), other.size());
-        m_size = other.size();
-    }
+    Vector(const Vector<T>& other) = delete;
 
     Vector(Vector<T>&& other)
     {
@@ -32,18 +27,7 @@ template <typename T> class Vector
         other.m_data = nullptr;
     }
 
-    Vector<T>& operator=(const Vector<T>& other)
-    {
-        if (&other == this) return *this;
-
-        if (m_data) clear();
-
-        reserve(other.capacity());
-        for (usize i = 0; i < other.size(); i++) { new (&m_data[i]) T(other.m_data[i]); }
-        m_size = other.size();
-
-        return *this;
-    }
+    Vector<T>& operator=(const Vector<T>& other) = delete;
 
     Vector<T>& operator=(Vector<T>&& other)
     {
@@ -217,6 +201,35 @@ template <typename T> class Vector
         m_data = nullptr;
     }
 
+    Result<Vector<T>> shallow_copy()
+    {
+        Vector<T> other;
+        TRY(other.try_reserve(m_capacity));
+        memcpy(other.m_data, m_data, m_size);
+        other.m_size = m_size;
+        return other;
+    }
+
+    Result<Vector<T>> deep_copy()
+    {
+        Vector<T> other;
+        TRY(other.try_reserve(m_capacity));
+        for (usize i = 0; i < m_size; i++) { TRY(other.try_append(m_data[i])); }
+        return other;
+    }
+
+    Result<Vector<T>> deep_copy(Result<T> (*copy_function)(const T&))
+    {
+        Vector<T> other;
+        TRY(other.try_reserve(m_capacity));
+        for (usize i = 0; i < m_size; i++)
+        {
+            auto copy = TRY(copy_function(m_data[i]));
+            TRY(other.try_append(move(copy)));
+        }
+        return other;
+    }
+
   private:
     T* m_data { nullptr };
     usize m_capacity { 0 };

libluna/src/Hash.cpp

@@ -0,0 +1,14 @@
+#include <luna/Hash.h>
+
+u64 hash_memory(const void* mem, usize size, u64 salt)
+{
+    const char* p = (const char*)mem;
+    u64 h = salt;
+    while (--size) h = h * 101 + (u64)*p++;
+    return h;
+}
+
+template <> u64 hash(const char* const& value, u64 salt)
+{
+    return hash_memory(value, strlen(value), salt);
+}

libos/include/os/ArgumentParser.h

@@ -1,46 +1,173 @@
+/**
+ * @file ArgumentParser.h
+ * @author apio (cloudapio.eu)
+ * @brief Command-line argument parser.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/StringView.h>
 #include <luna/Vector.h>
 
 namespace os
 {
+    /**
+     * @brief A simple command-line argument parser.
+     */
     class ArgumentParser
     {
       public:
+        /**
+         * @brief Construct a new ArgumentParser object.
+         */
         ArgumentParser();
 
+        /**
+         * @brief Add a description for this command-line utility (shown in the help text).
+         *
+         * @param description The description to use.
+         */
         void add_description(StringView description);
 
-        Result<void> add_positional_argument(StringView& out, StringView name, bool required);
+        /**
+         * @brief Register a new positional argument.
+         *
+         * @param out The variable where the argument's value will be stored.
+         * @param name The positional argument's name.
+         * @param fallback The value to use if the user does not provide one.
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> add_positional_argument(StringView& out, StringView name, StringView fallback);
 
+        /**
+         * @brief Register a new positional argument.
+         *
+         * @param out The variable where the argument's value will be stored.
+         * @param name The positional argument's name.
+         * @param required Whether the user must enter a value for this argument. If this is false and the user does not
+         * enter a value, out will be set to an empty string.
+         * @return Result<void> Whether the operation succeeded.
+         */
+        Result<void> add_positional_argument(StringView& out, StringView name, bool required);
+
+        /**
+         * @brief Register a new switch argument.
+         *
+         * @param out This variable will be set to true if the user provides the switch argument on the command
+         * line.
+         * @param short_flag The short flag to use for this argument, excluding the '-' prefix: an option '-c' would be
+         * passed as 'c'. Can only be a single ASCII character. If you do not wish this argument to have a short flag,
+         * use the space character: ' '.
+         * @param long_flag The long flag to use for this argument, excluding the '--' prefix: an option '--example'
+         * would be passed as 'example'. Can be a string of any length. If you do not wish this argument to have a long
+         * flag, use an empty string: "".
+         * @param help The help text to show for this argument (optional).
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> add_switch_argument(bool& out, char short_flag, StringView long_flag, StringView help = {});
 
-        Result<void> add_value_argument(StringView& out, char short_flag, StringView long_flag, bool value_required,
-                                        StringView help = {});
+        /**
+         * @brief Register a new value argument.
+         *
+         * @param out The variable where the argument's value will be stored.
+         * @param short_flag The short flag to use for this argument, excluding the '-' prefix: an option '-c' would be
+         * passed as 'c'. Can only be a single ASCII character. If you do not wish this argument to have a short flag,
+         * use the space character: ' '.
+         * @param long_flag The long flag to use for this argument, excluding the '--' prefix: an option '--example'
+         * would be passed as 'example'. Can be a string of any length. If you do not wish this argument to have a long
+         * flag, use an empty string: "".
+         * @param fallback The value to use if the user uses the argument but does not provide a value. If, however, the
+         * user does not specify this argument at all, out WILL NOT BE MODIFIED!
+         * @param help The help text to show for this argument (optional).
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> add_value_argument(StringView& out, char short_flag, StringView long_flag, StringView fallback,
                                         StringView help = {});
 
+        /**
+         * @brief Register a new value argument.
+         *
+         * @param out The variable where the argument's value will be stored.
+         * @param short_flag The short flag to use for this argument, excluding the '-' prefix: an option '-c' would be
+         * passed as 'c'. Can only be a single ASCII character. If you do not wish this argument to have a short flag,
+         * use the space character: ' '.
+         * @param long_flag The long flag to use for this argument, excluding the '--' prefix: an option '--example'
+         * would be passed as 'example'. Can be a string of any length. If you do not wish this argument to have a long
+         * flag, use an empty string: "".
+         * @param value_required Whether the user is required to pass a value when using this argument. If this is
+         * false and the user does not enter a value along with the argument, out will be set to an empty string. If,
+         * however, the user does not specify this argument at all, out WILL NOT BE MODIFIED!
+         * @param help The help text to show for this argument (optional).
+         * @return Result<void> Whether the operation succeeded.
+         */
+        Result<void> add_value_argument(StringView& out, char short_flag, StringView long_flag, bool value_required,
+                                        StringView help = {});
+
+        /**
+         * @brief Set the vector to append extra unregistered positional arguments to, after all
+         * registered positional arguments have been parsed. (If no vector is set, these values will instead be
+         * discarded!)
+         *
+         * @param out The vector of StringViews to use.
+         * @param allow_no_more_flags If set, after starting to append values into the vector, no more flags (switch and
+         * value arguments) will be parsed, and will instead be treated as regular positional arguments, as if '--' had
+         * been specified on the command line.
+         */
         void set_vector_argument(Vector<StringView>& out, bool allow_no_more_flags = false);
 
+        /**
+         * @brief Parse the given command-line using this ArgumentParser's registered arguments.
+         *
+         * @param argc The argc value passed to main() or luna_main().
+         * @param argv The argv value passed to main() or luna_main().
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> parse(int argc, char* const* argv);
 
+        /**
+         * @brief A program's copyright and version information.
+         */
         struct ProgramInfo
         {
-            StringView name;
-            StringView version;
-            StringView copyright;
-            StringView license;
-            StringView authors;
-            StringView package;
+            StringView name;      // The program's name.
+            StringView version;   // The program's version/release.
+            StringView copyright; // The program's copyright statement.
+            StringView license;   // The program's licensing information.
+            StringView authors;   // The program's authors (optional).
+            StringView package;   // The package the program is a part of (optional).
         };
 
+        /**
+         * @brief Set this program's copyright and version information (shown in the version text).
+         *
+         * @param info The program information to use.
+         */
         void add_program_info(ProgramInfo info);
 
-        /* Used from programs that are part of the Luna source tree, to add the same version info for all programs.
-         * Should not be used otherwise. */
+        /**
+         * @brief For programs that are part of the Luna source tree, set the version information using Luna's own
+         * version and copyright info and the program name.
+         *
+         * @param name The program name to show in the version information.
+         */
         void add_system_program_info(StringView name);
 
+        /**
+         * @brief Show a short message describing how to find usage information (usually "<program> --help").
+         *
+         * The actual message shown is:
+         *  "Try running '<program> --help' for more information." if --help has not been overridden.
+         *  "Try running '<program> -h' for more information." if -h has not been overridden.
+         *  If both have been overridden, no output is shown.
+         *
+         * Then, the program exits with a non-zero exit code.
+         * This function is designed to be used when the program detects an invalid argument value after parse() has run
+         * successfully.
+         *
+         * @param program_name The program name to show (usually argv[0]).
+         */
         void short_usage(StringView program_name);
 
       private:

libos/include/os/Directory.h

@@ -1,3 +1,12 @@
+/**
+ * @file Directory.h
+ * @author apio (cloudapio.eu)
+ * @brief A C++-friendly API for directory access.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <dirent.h>
 #include <luna/SharedPtr.h>
@@ -7,44 +16,85 @@
 
 namespace os
 {
+    /**
+     * @brief An object-oriented directory handle, which is closed when all references to it go out of scope.
+     */
     class Directory
     {
       public:
+        /**
+         * @brief Create a new Directory object from a path, and open the directory.
+         *
+         * @param path The path to open.
+         * @return Result<SharedPtr<Directory>> A new Directory object.
+         */
         static Result<SharedPtr<Directory>> open(const Path& path);
 
+        /**
+         * @brief A filter to skip certain directory entries.
+         */
         enum class Filter
         {
-            None,
-            Hidden,
-            ParentAndBase
+            None,         // Do not skip anything.
+            Hidden,       // Skip all hidden files (that start with a '.' character).
+            ParentAndBase // Skip only the '.' and '..' entries.
         };
 
+        /**
+         * @brief Read the next entry name from this Directory.
+         *
+         * @param filter The entries to filter out.
+         * @return Result<String> The next entry's name as an owned String object, or an empty string if
+         * there are no more entries.
+         */
         Result<String> next(Filter filter);
 
+        /**
+         * @brief Read the list of entry names from this Directory.
+         *
+         * @param filter The entries to filter out.
+         * @return Result<Vector<String>> The list of entry names.
+         */
         Result<Vector<String>> list_names(Filter filter);
 
+        /**
+         * @brief A directory entry with extra information.
+         */
         struct Entry
         {
-            String name;
-            mode_t mode;
-            usize size;
-            time_t mtime;
+            String name;  // The entry's name.
+            mode_t mode;  // The entry's file permissions.
+            usize size;   // The entry's size.
+            time_t mtime; // The entry's last modification time.
         };
 
+        /**
+         * @brief Read the list of entries from this Directory, fetching extra information for each one.
+         *
+         * @param filter The entries to filter out.
+         * @return Result<Vector<Entry>> The list of entries.
+         */
         Result<Vector<Entry>> list(Filter filter);
 
+        /**
+         * @brief Rewinds this Directory back to the beginning of its entry list.
+         */
         void rewind();
 
+        /**
+         * @brief Returns the file descriptor associated with this Directory.
+         *
+         * @return int The file descriptor.
+         */
         int fd()
         {
             return dirfd(m_dirp);
         }
 
         ~Directory();
-
-      private:
         Directory(Badge<Directory>);
 
+      private:
         DIR* m_dirp { nullptr };
     };
 }

libos/include/os/File.h

@@ -1,5 +1,14 @@
+/**
+ * @file File.h
+ * @author apio (cloudapio.eu)
+ * @brief A C++-friendly API for file access.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
-#include <bits/open-flags.h>
+#include <fcntl.h>
 #include <luna/Buffer.h>
 #include <luna/Result.h>
 #include <luna/SharedPtr.h>
@@ -9,52 +18,160 @@
 
 namespace os
 {
+    /**
+     * @brief An object-oriented file handle, which is closed when all references to it go out of scope.
+     */
     class File
     {
       public:
+        /**
+         * @brief The supported file opening modes.
+         */
         enum OpenMode
         {
-            ReadOnly = O_RDONLY,
-            WriteOnly = O_WRONLY | O_TRUNC,
-            ReadWrite = O_RDWR | O_TRUNC,
-            Append = O_WRONLY | O_APPEND,
-            ReadAppend = O_RDWR | O_APPEND,
+            ReadOnly = O_RDONLY,            // Open the file read-only.
+            WriteOnly = O_WRONLY | O_TRUNC, // Open the file write-only, truncating it.
+            ReadWrite = O_RDWR | O_TRUNC,   // Open the file read-write, truncating it.
+            Append = O_WRONLY | O_APPEND,   // Open the file write-only, and append to it.
+            ReadAppend = O_RDWR | O_APPEND, // Open the file read-write, and append to it.
         };
 
+        /**
+         * @brief Create a new File object from a file path, opening the file.
+         *
+         * @param path The path to open.
+         * @param flags The opening mode to pass to open(2).
+         * @return Result<SharedPtr<File>> A new File object, or ENOENT if the file did not exist.
+         */
         static Result<SharedPtr<File>> open(const Path& path, OpenMode flags);
+
+        /**
+         * @brief Create a new File object from a file path, opening the file or creating it if it does not exist.
+         *
+         * @param path The path to open.
+         * @param flags The opening mode to pass to open(2).
+         * @param mode If a new file is created, the file permissions to apply to it. (default: u=rw,g=r,o=r)
+         * @return Result<SharedPtr<File>> A new File object.
+         */
         static Result<SharedPtr<File>> open_or_create(const Path& path, OpenMode flags, mode_t mode = 0644);
+
+        /**
+         * @brief Create a new File object from a file path, creating the file but erroring out if the file already
+         * exists.
+         *
+         * @param path The path to open.
+         * @param flags The opening mode to pass to open(2).
+         * @param mode The file permissions to apply to the created file. (default: u=rw,g=r,o=r)
+         * @return Result<SharedPtr<File>> A new File object, or EEXIST if the file already existed.
+         */
         static Result<SharedPtr<File>> create(const Path& path, OpenMode flags, mode_t mode = 0644);
 
-        /*
-          If path is "-", return standard input (as is common for many CLI apps). Otherwise, open path for reading.
-
-          This function is a convenience function for CLI apps, so that they don't need to check path and open standard
-          input if necessary.
+        /**
+         * @brief If path is "-", return standard input (as is common for many CLI apps). Otherwise, open path for
+         * reading.
+         *
+         * @param path The path to open.
+         * @return Result<SharedPtr<File>> A new File object if path was not "-", or the File
+         * object for standard input if path was "-".
          */
         static Result<SharedPtr<File>> open_input_file(StringView path);
 
+        /**
+         * @brief Returns the File corresponding to standard input.
+         *
+         * @return SharedPtr<File> The File object for standard input.
+         */
         static SharedPtr<File> standard_input();
+
+        /**
+         * @brief Returns the File corresponding to standard output.
+         *
+         * @return SharedPtr<File> The File object for standard output.
+         */
         static SharedPtr<File> standard_output();
+
+        /**
+         * @brief Returns the File corresponding to standard error.
+         *
+         * @return SharedPtr<File> The File object for standard error.
+         */
         static SharedPtr<File> standard_error();
 
+        /**
+         * @brief Make this File object automatically close on the next call to execve(2).
+         */
         void set_close_on_exec();
 
+        /**
+         * @brief Write a string to this File.
+         *
+         * @param str The string to write (can be not null-terminated).
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> write(StringView str);
+
+        /**
+         * @brief Write a memory buffer to this File.
+         *
+         * @param buf The buffer to write.
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> write(const Buffer& buf);
 
+        /**
+         * @brief Read a line from this File.
+         *
+         * @return Result<String> The line as an owned String object, or an empty string if there is no more
+         * data to read.
+         */
         Result<String> read_line();
+
+        /**
+         * @brief Read the entire File's contents as a string.
+         *
+         * @return Result<String> The file's contents as an owned String object.
+         */
         Result<String> read_all_as_string();
 
+        /**
+         * @brief Read data from this File.
+         *
+         * @param buf The output buffer to store the data in. Will be resized to fit the data.
+         * @param size The maximum number of bytes to read.
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> read(Buffer& buf, usize size);
+
+        /**
+         * @brief Read the entire File's contents.
+         *
+         * @return Result<Buffer> The file's contents as an owned Buffer object.
+         */
         Result<Buffer> read_all();
 
+        /**
+         * @brief Read a single character from the File.
+         *
+         * @return Result<int> A character value above 0 (to be cast to an unsigned char), or EOF (typically -1)
+         * if there is no more data to read.
+         */
         Result<int> getchar();
 
+        /**
+         * @brief Returns the file descriptor associated with this File.
+         *
+         * @return int The file descriptor.
+         */
         int fd() const
         {
             return m_fd;
         }
 
+        /**
+         * @brief Move this File's file pointer back to the beginning.
+         */
+        void rewind();
+
         File(Badge<File>);
         ~File();
 
@@ -68,8 +185,39 @@ namespace os
         int m_fd { -1 };
     };
 
+    /**
+     * @brief Print a formatted string to standard output.
+     *
+     * @param fmt The format string (in the same format as printf(3)).
+     * @param ... The format arguments.
+     * @return Result<void> Whether the operation succeeded.
+     */
     Result<void> print(StringView fmt, ...);
+
+    /**
+     * @brief Print a newline-terminated formatted string to standard output.
+     *
+     * @param fmt The format string (in the same format as printf(3)).
+     * @param ... The format arguments.
+     * @return Result<void> Whether the operation succeeded.
+     */
     Result<void> println(StringView fmt, ...);
+
+    /**
+     * @brief Print a formatted string to standard error.
+     *
+     * @param fmt The format string (in the same format as printf(3)).
+     * @param ... The format arguments.
+     * @return Result<void> Whether the operation succeeded.
+     */
     Result<void> eprint(StringView fmt, ...);
+
+    /**
+     * @brief Print a newline-terminated formatted string to standard error.
+     *
+     * @param fmt The format string (in the same format as printf(3)).
+     * @param ... The format arguments.
+     * @return Result<void> Whether the operation succeeded.
+     */
     Result<void> eprintln(StringView fmt, ...);
 }

libos/include/os/FileSystem.h

@@ -1,31 +1,111 @@
+/**
+ * @file FileSystem.h
+ * @author apio (cloudapio.eu)
+ * @brief APIs to read and modify the general file system.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
-#include <bits/struct_stat.h>
 #include <luna/Result.h>
 #include <luna/StringView.h>
 #include <os/Path.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 
 namespace os
 {
     namespace FileSystem
     {
+        /**
+         * @brief Check whether a given path exists.
+         *
+         * @param path The path to check.
+         * @param follow_symlinks If path is a symbolic link, whether to follow it (defaults to true).
+         * @return true The path exists.
+         * @return false The path does not exist, or it was a symbolic link and following it leaded to a nonexistent
+         * path.
+         */
         bool exists(const Path& path, bool follow_symlinks = true);
 
+        /**
+         * @brief Check whether a given path is a directory.
+         *
+         * @param path The path to check.
+         * @param follow_symlinks If path is a symbolic link, whether to follow it (defaults to false).
+         * @return true The path is a directory, or the path was a symbolic link and following it leaded to a directory.
+         * @return false The path does not exist, or it is not a directory.
+         */
         bool is_directory(const Path& path, bool follow_symlinks = false);
 
+        /**
+         * @brief Retrieve file status information.
+         *
+         * @param path The path to examine.
+         * @param st The buffer to store file status information in.
+         * @param follow_symlinks If path is a symbolic link, whether to follow it and retrieve its target's status, or
+         * otherwise retrieve the symbolic link's status (defaults to true).
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> stat(const Path& path, struct stat& st, bool follow_symlinks = true);
 
+        /**
+         * @brief Create a new directory in the file system.
+         *
+         * @param path The path for the new directory.
+         * @param mode The file permissions to apply to the new directory.
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> create_directory(StringView path, mode_t mode);
 
+        /**
+         * @brief Remove a file or empty directory from the file system. (The file will continue to exist if there are
+         * other hard links to it or a process still has it open.)
+         *
+         * @param path The path to remove.
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> remove(const Path& path);
 
+        /**
+         * @brief Remove a directory tree from the file system recursively, deleting subfiles and subdirectories as
+         * well.
+         *
+         * @param path The path to remove.
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> remove_tree(const Path& path);
 
+        /**
+         * @brief Read the target of a symbolic link.
+         *
+         * @param path The symbolic link's path.
+         * @return Result<String> If the path was not a symbolic link, an empty string, otherwise the symbolic link's
+         * target.
+         */
         Result<String> readlink(const Path& path);
 
+        /**
+         * @brief Read the current process's working directory.
+         *
+         * @return Result<String> The working directory as an owned String object.
+         */
         Result<String> working_directory();
+
+        /**
+         * @brief Fetch the current user' home directory.
+         *
+         * @return Result<String> The home directory as an owned String object.
+         */
         Result<String> home_directory();
 
+        /**
+         * @brief Change the current process's working directory.
+         *
+         * @param path The new working directory.
+         * @return Result<void> Whether the operation succeeded.
+         */
         Result<void> change_directory(StringView path);
     }
 }

libos/include/os/Main.h

@@ -1,4 +1,21 @@
+/**
+ * @file Main.h
+ * @author apio (cloudapio.eu)
+ * @brief Alternative C++ main function.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/Result.h>
 
-Result<int> luna_main(int argc, char** argv);
+/**
+ * @brief The main() function for Luna C++ apps. This function is extern as it should be implemented by the user if they
+ * do not implement the C main() function.
+ *
+ * @param argc The argc parameter passed to the regular main() function.
+ * @param argv The argv parameter passed to the regular main() function.
+ * @return Result<int> A normal status code, or an errno code, which will be displayed along with an abnormal exit code.
+ */
+extern Result<int> luna_main(int argc, char** argv);

libos/include/os/Mode.h

@@ -1,8 +1,30 @@
+/**
+ * @file Mode.h
+ * @author apio (cloudapio.eu)
+ * @brief Visual file permissions parsing and formatting.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 
 #include <sys/types.h>
 
 namespace os
 {
+    /**
+     * @brief Create a visual representation of file permissions using the integral representation.
+     *
+     * The output is formatted in the same style as the output of "ls -l".
+     * For example:
+     * An integral mode of S_IFREG | 0644 would result in "-rw-r--r--".
+     * An integral mode of S_IFDIR | 0755 would result in "drwxr-xr-x".
+     * An integral mode of S_IFLNK | 0777 would result in "lrwxrwxrwx".
+     *
+     * @param mode The integral mode.
+     * @param out The buffer to store the formatted file permissions in, as a C-string (minimum 11 bytes, including the
+     * terminating null byte).
+     */
     void format_mode(mode_t mode, char out[11]);
 }

libos/include/os/Path.h

@@ -1,27 +1,78 @@
+/**
+ * @file Path.h
+ * @author apio (cloudapio.eu)
+ * @brief Dirfd-friendly Path class.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <fcntl.h>
 #include <luna/StringView.h>
 
 namespace os
 {
+    /**
+     * @brief A dirfd-friendly Path class.
+     */
     class Path
     {
       public:
+        /**
+         * @brief Construct a new Path object using a C-string file path.
+         *
+         * @param path The file path to use.
+         */
         Path(const char* path);
+
+        /**
+         * @brief Construct a new Path object using a StringView file path.
+         *
+         * @param path The file path to use.
+         */
         Path(StringView path);
+
+        /**
+         * @brief Construct a new Path object using a file descriptor.
+         *
+         * @param fd The file descriptor to use.
+         */
         Path(int fd);
+
+        /**
+         * @brief Construct a new Path object using a parent file descriptor and a file path.
+         *
+         * @param dirfd The parent file descriptor to use.
+         * @param name The file path to use.
+         */
         Path(int dirfd, StringView name);
 
+        /**
+         * @brief Return the file descriptor associated with this Path.
+         *
+         * @return int The file descriptor, or AT_FDCWD if this Path does not have one.
+         */
         int dirfd() const
         {
             return m_dirfd.value_or(AT_FDCWD);
         }
 
+        /**
+         * @brief Return the file path associated with this Path.
+         *
+         * @return StringView The path, or an empty StringView if this Path does not have one.
+         */
         StringView name() const
         {
             return m_name.value_or(""_sv);
         }
 
+        /**
+         * @brief Determine whether this Path consists only of a file descriptor.
+         *
+         * @return int The fstatat()-compatible flag value to use in case this Path consists only of a file descriptor.
+         */
         int is_empty_path() const
         {
             if (m_dirfd.has_value() && !m_name.has_value()) return AT_EMPTY_PATH;

libos/include/os/Process.h

@@ -1,17 +1,76 @@
+/**
+ * @file Process.h
+ * @author apio (cloudapio.eu)
+ * @brief Functions to manipulate processes.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/Result.h>
 #include <luna/String.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 
 namespace os
 {
+    /**
+     * @brief An object representing a process.
+     */
     class Process
     {
       public:
+        /**
+         * @brief Create a new process, which is an identical copy of the current one.
+         *
+         * @return Result<pid_t> The child's process ID in the parent process, and 0 in the child process.
+         */
         static Result<pid_t> fork();
 
+        /**
+         * @brief Replace the current process's executable with another one.
+         *
+         * @param path The new executable's path.
+         * @param args The argument list to pass to the new executable.
+         * @param search_in_path Determines whether to search in the system binary directories if path is just a name.
+         * @return Result<void> Always an error, as this function does not return on success.
+         */
         static Result<void> exec(StringView path, Slice<String> args, bool search_in_path = true);
+
+        /**
+         * @brief Replace the current process's executable with another one.
+         *
+         * @param path The new executable's path.
+         * @param args The argument list to pass to the new executable.
+         * @param search_in_path Determines whether to search in the system binary directories if path is just a name.
+         * @return Result<void> Always an error, as this function does not return on success.
+         */
         static Result<void> exec(StringView path, Slice<StringView> args, bool search_in_path = true);
+
+        /**
+         * @brief Replace the current process's executable with another one.
+         *
+         * @param path The new executable's path.
+         * @param args The argument list to pass to the new executable.
+         * @param env The environment to pass to the new executable, instead of the current environment.
+         * @param search_in_path Determines whether to search in the system binary directories if path is just a name.
+         * @return Result<void> Always an error, as this function does not return on success.
+         */
         static Result<void> exec(StringView path, Slice<String> args, Slice<String> env, bool search_in_path = true);
+
+        // To use as the child argument to wait() to wait for any child.
+        static constexpr pid_t ANY_CHILD = -1;
+
+        /**
+         * @brief Wait for a child process to finish running.
+         *
+         * @param child The process ID of the child process, or ANY_CHILD to wait for any child.
+         * @param status The child's exit status will be stored here. If you don't want it, use nullptr.
+         * @param options Options to pass to waitpid(2).
+         * @return Result<pid_t> The process ID of the child process that was waited for (may not be the same as the
+         * child argument if ANY_CHILD was passed).
+         */
+        static Result<pid_t> wait(pid_t child, int* status, int options = 0);
     };
 }

libos/src/ArgumentParser.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file ArgumentParser.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Command-line argument parser.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <luna/StringBuilder.h>
 #include <os/ArgumentParser.h>
 #include <os/File.h>
@@ -75,6 +84,7 @@ namespace os
         return;
     }
 
+    // Change this every year!
     constexpr auto copyright_text = "Copyright (C) 2023, the Luna authors.";
     constexpr auto license_text = "Licensed under the BSD-2 license <https://opensource.org/license/bsd-2-clause/>";
 

libos/src/Directory.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Directory.cpp
+ * @author apio (cloudapio.eu)
+ * @brief A C++-friendly API for directory access.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <errno.h>
 #include <fcntl.h>
 #include <luna/CString.h>

libos/src/File.cpp

@@ -1,4 +1,12 @@
-#include <fcntl.h>
+/**
+ * @file File.cpp
+ * @author apio (cloudapio.eu)
+ * @brief A C++-friendly API for file access.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <luna/StringBuilder.h>
 #include <os/File.h>
 #include <sys/syscall.h>
@@ -194,6 +202,11 @@ namespace os
         fcntl(m_fd, F_SETFD, FD_CLOEXEC);
     }
 
+    void File::rewind()
+    {
+        lseek(m_fd, 0, SEEK_SET);
+    }
+
     // FIXME: Do not allocate memory for printing.
     Result<void> print_impl(SharedPtr<File> f, StringView fmt, va_list ap)
     {

libos/src/FileSystem.cpp

@@ -1,4 +1,12 @@
-#include <bits/modes.h>
+/**
+ * @file FileSystem.cpp
+ * @author apio (cloudapio.eu)
+ * @brief APIs to read and modify the general file system.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -33,9 +41,8 @@ namespace os::FileSystem
 
     Result<void> stat(const Path& path, struct stat& st, bool follow_symlinks)
     {
-        long rc =
-            syscall(SYS_fstatat, path.dirfd(), path.name().chars(), &st,
-                    (int)((path.is_empty_path() ? AT_EMPTY_PATH : 0) | (follow_symlinks ? 0 : AT_SYMLINK_NOFOLLOW)));
+        long rc = syscall(SYS_fstatat, path.dirfd(), path.name().chars(), &st,
+                          (int)(path.is_empty_path() | (follow_symlinks ? 0 : AT_SYMLINK_NOFOLLOW)));
 
         return Result<void>::from_syscall(rc);
     }

libos/src/Main.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Main.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Alternative C++ main function.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <errno.h>
 #include <os/Main.h>
 #include <stdio.h>
@@ -5,6 +14,8 @@
 int g_argc;
 char** g_argv;
 
+// This function will only be linked into the final binary if the user does not already define main(), which implies
+// that they should have defined luna_main() instead. If not, good for them: linker errors!
 __attribute__((weak)) int main(int argc, char** argv)
 {
     g_argc = argc;

libos/src/Mode.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Mode.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Visual file permissions parsing and formatting.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <os/Mode.h>
 #include <sys/stat.h>
 

libos/src/Path.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Path.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Dirfd-friendly Path class.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <os/Path.h>
 
 namespace os

libos/src/Process.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Process.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Functions to manipulate processes.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <errno.h>
 #include <os/Process.h>
 #include <sys/syscall.h>
@@ -53,4 +62,10 @@ namespace os
 
         return err(errno);
     }
+
+    Result<pid_t> Process::wait(pid_t child, int* status, int options)
+    {
+        long rc = syscall(SYS_waitpid, child, status, options);
+        return Result<pid_t>::from_syscall(rc);
+    }
 }

tests/CMakeLists.txt

@@ -17,6 +17,7 @@ luna_test(libluna/TestVector.cpp TestVector)
 luna_test(libluna/TestBase64.cpp TestBase64)
 luna_test(libluna/TestUtf8.cpp TestUtf8)
 luna_test(libluna/TestFormat.cpp TestFormat)
+luna_test(libluna/TestHashTable.cpp TestHashTable)
 
 luna_app(run-tests.cpp run-tests)
 endif()

tests/libluna/TestHashTable.cpp

@@ -0,0 +1,79 @@
+#include <luna/HashTable.h>
+#include <os/File.h>
+#include <test.h>
+
+struct TwoInts
+{
+    int a;
+    int b;
+
+    bool operator==(TwoInts other) const
+    {
+        return other.a == a;
+    }
+};
+
+template <> u64 hash(const TwoInts& value, u64 salt)
+{
+    return hash(value.a, salt);
+}
+
+TestResult test_empty_hash_table()
+{
+    HashTable<int> table;
+
+    validate(table.try_find(0) == nullptr);
+
+    test_success;
+}
+
+TestResult test_hash_table_find()
+{
+    HashTable<int> table;
+
+    validate(TRY(table.try_set(0)));
+
+    validate(table.try_find(0));
+    validate(table.try_find(1) == nullptr);
+
+    test_success;
+}
+
+TestResult test_hash_table_remove()
+{
+    HashTable<int> table;
+
+    validate(TRY(table.try_set(0)));
+
+    validate(table.try_find(0));
+
+    validate(table.try_remove(0));
+
+    validate(table.try_find(0) == nullptr);
+
+    test_success;
+}
+
+TestResult test_hash_table_duplicates()
+{
+    HashTable<TwoInts> table;
+
+    validate(TRY(table.try_set(TwoInts { 1, 5 })));
+    validate(!TRY(table.try_set(TwoInts { 1, 3 })));
+
+    validate(table.try_find(TwoInts { 1, 0 })->b == 5);
+
+    test_success;
+}
+
+Result<void> test_main()
+{
+    test_prelude;
+
+    run_test(test_empty_hash_table);
+    run_test(test_hash_table_find);
+    run_test(test_hash_table_remove);
+    run_test(test_hash_table_duplicates);
+
+    return {};
+}

tests/run-tests.cpp

@@ -17,7 +17,7 @@ Result<int> luna_main(int argc, char** argv)
 
     auto dir = TRY(os::Directory::open(test_dir));
 
-    auto files = TRY(dir->list(os::Directory::Filter::Hidden));
+    auto files = TRY(dir->list_names(os::Directory::Filter::Hidden));
 
     for (const auto& program : files)
     {