refactor: kernel entry point - add architecture preprocessor checks and move module to Boot

kernel/src/Boot/Main.cpp

@@ -0,0 +1,211 @@
+/*
+    * main.cpp
+    * Kernel entry point
+    * Copyright (c) 2025 Daniel Hammer.
+    * Further copyright information and third party notices can be found at https://montaukos.org/license.txt.
+*/
+
+#include <cstdint>
+#include <cstddef>
+#include <Boot/Boot.hpp>
+#include <Hal/GDT.hpp>
+#include <Terminal/Terminal.hpp>
+#include <Efi/UEFI.hpp>
+#include <Common/Panic.hpp>
+#include <Memory/Memmap.hpp>
+#include <Memory/Heap.hpp>
+#include <Memory/HHDM.hpp>
+#include <Platform/Util.hpp>
+#include <Hal/IDT.hpp>
+#include <Memory/PageFrameAllocator.hpp>
+#include <Memory/Paging.hpp>
+#include <ACPI/ACPI.hpp>
+#include <ACPI/CpuIdle.hpp>
+#include <ACPI/AcpiShutdown.hpp>
+#include <ACPI/AcpiEvents.hpp>
+#include <Hal/Apic/ApicInit.hpp>
+#include <Pci/Pci.hpp>
+#include <Timekeeping/ApicTimer.hpp>
+#include <Drivers/PS2/PS2Controller.hpp>
+#include <Drivers/PS2/Keyboard.hpp>
+#include <Drivers/PS2/Mouse.hpp>
+#include <Drivers/Init.hpp>
+#include <Graphics/Framebuffer.hpp>
+#include <Hal/MSR.hpp>
+#include <Hal/Cpu.hpp>
+#include <Hal/CpuPower.hpp>
+#include <Fs/Boot.hpp>
+#include <Sched/Scheduler.hpp>
+#include <Ipc/Ipc.hpp>
+#include <Api/Syscall.hpp>
+#include <Hal/SmpBoot.hpp>
+using namespace Kt;
+
+namespace Memory {
+    HeapAllocator* g_heap;
+    PageFrameAllocator* g_pfa;
+    uint64_t HHDMBase;
+};
+
+KernelOutStream kout{};
+KernelErrorStream kerr{};
+
+// Extern declarations for global constructors array.
+extern void (*__init_array[])();
+extern void (*__init_array_end[])();
+
+extern "C" uint64_t KernelStartSymbol;
+extern "C" uint64_t KernelEndSymbol;
+
+extern "C" void kmain() {
+    // Call global constructors.
+    for (std::size_t i = 0; &__init_array[i] != __init_array_end; i++) {
+        __init_array[i]();
+    }
+    
+    if (!montauk::boot::Initialize()) {
+        Hal::Halt();
+    }
+    const montauk::boot::BootInfo& boot = montauk::boot::Info();
+    const montauk::boot::Framebuffer& framebuffer = boot.framebuffer;
+
+    Kt::Initialize(
+        (uint32_t*)framebuffer.address,
+        framebuffer.width,
+        framebuffer.height,
+        framebuffer.pitch,
+        framebuffer.redMaskSize,
+        framebuffer.redMaskShift,
+        framebuffer.greenMaskSize,
+        framebuffer.greenMaskShift,
+        framebuffer.blueMaskSize,
+        framebuffer.blueMaskShift
+    );
+
+
+#if defined (__x86_64__)
+    Hal::PrepareGDT();
+    Hal::BridgeLoadGDT();
+
+    Hal::EnableSSE();
+#endif
+
+    Memory::HHDMBase = boot.hhdmBase;
+
+    if (boot.memoryMap.regions == nullptr || boot.memoryMap.count == 0) {
+        Panic("System memory map missing!", nullptr);
+    }
+
+    Kt::KernelLogStream(OK, "Mem") << "Creating PageFrameAllocator";
+    Memory::PageFrameAllocator pmm(Memory::Scan(boot.memoryMap));
+    Memory::g_pfa = &pmm;
+
+    Kt::KernelLogStream(OK, "Mem") << "Creating HeapAllocator";
+    Memory::HeapAllocator heap{};
+    Memory::g_heap = &heap;
+
+    heap.Walk();
+
+
+#if defined (__x86_64__)
+    Hal::IDTInitialize();
+
+    Memory::VMM::Paging g_paging{};
+    Memory::VMM::g_paging = &g_paging;
+    g_paging.Init((uint64_t)&KernelStartSymbol, ((uint64_t)&KernelEndSymbol - (uint64_t)&KernelStartSymbol), boot.memoryMap, framebuffer);
+
+    Hal::InitializePAT();
+
+#endif
+
+    Graphics::Framebuffer::Initialize(framebuffer);
+
+#if defined (__x86_64__)
+    Graphics::Framebuffer::MapWriteCombining();
+#endif
+
+    Hal::ACPI g_acpi((Hal::ACPI::XSDP*)Memory::HHDM(boot.rsdpPhysical));
+
+#if defined (__x86_64__)
+    if (g_acpi.GetXSDT() != nullptr) {
+        Hal::AcpiShutdown::Initialize(g_acpi.GetXSDT());
+        Hal::CpuIdle::Initialize(g_acpi.GetXSDT());
+
+        Hal::ApicInitialize(g_acpi.GetXSDT());
+
+        Smp::InitBsp();
+
+        Hal::CpuPower::InitializeBsp();
+
+        asm volatile("sti");
+
+        Hal::AcpiEvents::Initialize(g_acpi.GetXSDT());
+
+        Pci::Initialize(g_acpi.GetXSDT());
+
+        Drivers::ProbeEarly();
+        Drivers::InitializeGraphics();
+
+        Timekeeping::ApicTimerInitialize();
+
+        Drivers::PS2::Initialize();
+        Drivers::PS2::Keyboard::Initialize();
+        Drivers::PS2::Mouse::Initialize();
+
+        Drivers::ProbeNormal();
+        Drivers::InitializeNetwork();
+        Drivers::InitializeStorage();
+        Drivers::InitializeAudio();
+    }
+#endif
+
+    // UEFI runtime services are optional (absent on legacy-BIOS boots).
+    if (boot.has(montauk::boot::FeatureEfiSystemTable)) {
+        Efi::SystemTable* ST = (Efi::SystemTable*)Memory::HHDM(boot.efi.systemTablePhysical);
+        Efi::Init(ST, boot.efi);
+    }
+
+    Fs::InitializeBootFilesystems(boot.modules);
+
+#if defined (__x86_64__)
+    Hal::LoadTSS();
+#endif
+
+    montauk::abi::InitializeSyscalls();
+
+    Sched::Initialize();
+    Ipc::Initialize();
+
+#if defined (__x86_64__)
+    Smp::BootAPs(boot.smp);
+#endif
+
+#if defined (__x86_64__)
+    Drivers::PS2::Mouse::FlushState();
+#endif
+
+    Kt::SuppressKernelLog();
+    Sched::Spawn("0:/os/init.elf");
+
+    Timekeeping::EnableSchedulerTick();
+
+#if defined (__x86_64__)
+    // Use MWAIT for deeper C-states if available, otherwise HLT.
+    auto* bspCpu = Smp::GetCpuData(0);
+    
+    if (bspCpu && bspCpu->hasMwait) {
+        static volatile uint64_t s_bspIdleMonitor = 0;
+        for (;;) {
+            Timekeeping::IdleOnce(true, &s_bspIdleMonitor);
+        }
+    } else {
+        for (;;) {
+            Timekeeping::IdleOnce(false);
+        }
+    }
+#else
+    for (;;) {
+        Timekeeping::IdleOnce(false);
+    }
+#endif
+}