Add a KernelMemoryManager namespace to wrap PMM + VMM

kernel/Makefile

@@ -8,7 +8,7 @@ CXX := x86_64-elf-g++
 AS := x86_64-elf-as
 NASM := nasm
 
-CFLAGS := -Wall -Wextra -Werror -Os -ffreestanding -mno-red-zone -mno-mmx -mno-sse -mno-sse2 -fshort-wchar -mcmodel=kernel -I$(MOON_DIR)/include -isystem $(MOON_DIR)/include/std
+CFLAGS := -g -Wall -Wextra -Werror -Os -ffreestanding -mno-red-zone -mno-mmx -mno-sse -mno-sse2 -fshort-wchar -mcmodel=kernel -I$(MOON_DIR)/include -isystem $(MOON_DIR)/include/std
 CXXFLAGS := -fno-rtti -fno-exceptions
 NASMFLAGS := -felf64
 ASFLAGS :=

kernel/include/memory/KernelMemoryManager.h

@@ -0,0 +1,14 @@
+#pragma once
+#include <stdint.h>
+
+namespace KernelMemoryManager
+{
+    void* get_mapping(void* physicalAddress);
+    void release_mapping(void* mapping);
+
+    void* get_page();
+    void* get_pages(uint64_t count);
+
+    void release_page(void* page);
+    void release_pages(void* pages, uint64_t count);
+}

kernel/include/memory/RangeAllocator.h

@@ -35,4 +35,4 @@ class RangeAllocator
     uint64_t start_index = 0;
 };
 
-extern RangeAllocator physical_allocator;
+extern RangeAllocator kernelPMM;

kernel/include/memory/VMM.h

@@ -11,6 +11,7 @@ namespace Paging
 
         void map(uint64_t virtualAddress, uint64_t physicalAddress);
         void unmap(uint64_t virtualAddress);
+        uint64_t getPhysical(uint64_t virtualAddress);
 
       private:
         PageTable* PML4;

kernel/src/init/Init.cpp

@@ -32,6 +32,6 @@ void Init::early_init()
     ASSERT(Draw::try_initialize());
     // ASSERT(TextRenderer::try_initialize());
 
-    physical_allocator.init_from_mmap();
+    kernelPMM.init_from_mmap();
     kernelVMM.init();
 }

kernel/src/interrupts/Entry.cpp

@@ -13,6 +13,11 @@ extern "C" void common_handler(SavedContext* context)
                context->rsp, context->error_code, context->cr2);
         while (1) halt();
     }
+    if (context->number == 14)
+    {
+        printf("Page fault at 0x%zx\n");
+        hang();
+    }
     if (context->number >= 0x20 && context->number < 0x30) { IRQ::interrupt_handler(context); }
     return;
 }

kernel/src/main.cpp

@@ -13,6 +13,7 @@
 #include "io/Serial.h"
 #include "log/Log.h"
 #include "memory/KernelHeap.h"
+#include "memory/KernelMemoryManager.h"
 #include "memory/Memory.h"
 #include "memory/RangeAllocator.h"
 #include "panic/hang.h"
@@ -74,27 +75,6 @@ extern "C" void _start()
 
     kinfoln("Interrupts enabled");
 
-    printf("%d KB of system memory\n%d KB free\n%d KB used\n%d KB reserved\n", Memory::get_system() / 1024,
-           physical_allocator.get_free() / 1024, physical_allocator.get_used() / 1024,
-           physical_allocator.get_reserved() / 1024);
-
-    void* address = physical_allocator.request_page();
-    printf("Allocated page at address 0x%zx\n", address);
-
-    void* address2 = physical_allocator.request_page();
-    printf("Allocated page at address 0x%zx\n", address2);
-
-    printf("%d KB of system memory\n%d KB free\n%d KB used\n%d KB reserved\n", Memory::get_system() / 1024,
-           physical_allocator.get_free() / 1024, physical_allocator.get_used() / 1024,
-           physical_allocator.get_reserved() / 1024);
-
-    physical_allocator.free_page(address);
-    printf("Freed page\n");
-
-    printf("%d KB of system memory\n%d KB free\n%d KB used\n%d KB reserved\n", Memory::get_system() / 1024,
-           physical_allocator.get_free() / 1024, physical_allocator.get_used() / 1024,
-           physical_allocator.get_reserved() / 1024);
-
     Debug::DebugStatus::the()->StartBootStage(Color{0x33, 0x33, 0x00, 0xFF});
     ACPI::SDTHeader* rootSDT = ACPI::GetRSDTOrXSDT();
     bool isXSDT = false;

kernel/src/memory/KernelMemoryManager.cpp

@@ -0,0 +1,58 @@
+#include "memory/KernelMemoryManager.h"
+#include "assert.h"
+#include "memory/KernelHeap.h"
+#include "memory/RangeAllocator.h"
+#include "memory/VMM.h"
+
+void* KernelMemoryManager::get_mapping(void* physicalAddress)
+{
+    uint64_t virtualAddress = KernelHeap::request_virtual_page();
+    kernelVMM.map(virtualAddress, (uint64_t)physicalAddress);
+    return (void*)virtualAddress;
+}
+
+void KernelMemoryManager::release_mapping(void* mapping)
+{
+    kernelVMM.unmap((uint64_t)mapping);
+}
+
+void* KernelMemoryManager::get_page()
+{
+    void* physicalAddress = kernelPMM.request_page();
+    uint64_t virtualAddress = KernelHeap::request_virtual_page();
+    kernelVMM.map(virtualAddress, (uint64_t)physicalAddress);
+    return (void*)virtualAddress;
+}
+
+void KernelMemoryManager::release_page(void* page)
+{
+    uint64_t physicalAddress = kernelVMM.getPhysical((uint64_t)page);
+    ASSERT(physicalAddress != UINT64_MAX);
+    kernelVMM.unmap((uint64_t)page);
+    kernelPMM.free_page((void*)physicalAddress);
+    KernelHeap::free_virtual_page((uint64_t)page);
+}
+
+void* KernelMemoryManager::get_pages(uint64_t count)
+{
+    uint64_t virtualAddress = KernelHeap::request_virtual_pages(count);
+    for (uint64_t i = 0; i < count; i++)
+    {
+        void* physicalAddress = kernelPMM.request_page();
+        kernelVMM.map(virtualAddress + (i * 4096), (uint64_t)physicalAddress);
+    }
+    return (void*)virtualAddress;
+}
+
+void KernelMemoryManager::release_pages(void* pages, uint64_t count)
+{
+    for (uint64_t i = 0; i < count; i++)
+    {
+        void* page = (void*)((uint64_t)pages + (i * 4096));
+        uint64_t physicalAddress = kernelVMM.getPhysical((uint64_t)page);
+        ASSERT(physicalAddress != UINT64_MAX);
+        kernelVMM.unmap((uint64_t)page);
+        kernelPMM.free_page((void*)physicalAddress);
+    }
+    KernelHeap::free_virtual_pages((uint64_t)pages, count);
+}

kernel/src/memory/RangeAllocator.cpp

@@ -6,7 +6,7 @@
 
 extern BOOTBOOT bootboot;
 
-RangeAllocator physical_allocator;
+RangeAllocator kernelPMM;
 
 void RangeAllocator::init_from_mmap()
 {

kernel/src/memory/VMM.cpp

@@ -1,4 +1,5 @@
 #include "memory/VMM.h"
+#include "log/Log.h"
 #include "memory/RangeAllocator.h"
 #include "std/string.h"
 
@@ -59,6 +60,47 @@ namespace Paging
         PT->entries[P_i] = PDE;
     }
 
+    uint64_t VirtualMemoryManager::getPhysical(uint64_t virtualAddress)
+    {
+        virtualAddress >>= 12;
+        uint64_t P_i = virtualAddress & 0x1ff;
+        virtualAddress >>= 9;
+        uint64_t PT_i = virtualAddress & 0x1ff;
+        virtualAddress >>= 9;
+        uint64_t PD_i = virtualAddress & 0x1ff;
+        virtualAddress >>= 9;
+        uint64_t PDP_i = virtualAddress & 0x1ff;
+
+        PageDirectoryEntry PDE;
+
+        PDE = PML4->entries[PDP_i];
+        PageTable* PDP;
+        if (!PDE.Present)
+        {
+            return UINT64_MAX; // Not mapped
+        }
+        else { PDP = (PageTable*)((uint64_t)PDE.Address << 12); }
+
+        PDE = PDP->entries[PD_i];
+        PageTable* PD;
+        if (!PDE.Present)
+        {
+            return UINT64_MAX; // Not mapped
+        }
+        else { PD = (PageTable*)((uint64_t)PDE.Address << 12); }
+
+        PDE = PD->entries[PT_i];
+        PageTable* PT;
+        if (!PDE.Present)
+        {
+            return UINT64_MAX; // Not mapped
+        }
+        else { PT = (PageTable*)((uint64_t)PDE.Address << 12); }
+
+        PDE = PT->entries[P_i];
+        return PDE.Address;
+    }
+
     void VirtualMemoryManager::map(uint64_t virtualAddress, uint64_t physicalAddress)
     {
         virtualAddress >>= 12;
@@ -76,7 +118,7 @@ namespace Paging
         PageTable* PDP;
         if (!PDE.Present)
         {
-            PDP = (PageTable*)physical_allocator.request_page();
+            PDP = (PageTable*)kernelPMM.request_page();
             memset(PDP, 0, 0x1000);
             PDE.Address = (uint64_t)PDP >> 12;
             PDE.Present = true;
@@ -89,8 +131,8 @@ namespace Paging
         PageTable* PD;
         if (!PDE.Present)
         {
-            PD = (PageTable*)physical_allocator.request_page();
-            memset(PDP, 0, 0x1000);
+            PD = (PageTable*)kernelPMM.request_page();
+            memset(PD, 0, 0x1000);
             PDE.Address = (uint64_t)PD >> 12;
             PDE.Present = true;
             PDE.ReadWrite = true;
@@ -102,8 +144,8 @@ namespace Paging
         PageTable* PT;
         if (!PDE.Present)
         {
-            PT = (PageTable*)physical_allocator.request_page();
-            memset(PDP, 0, 0x1000);
+            PT = (PageTable*)kernelPMM.request_page();
+            memset(PT, 0, 0x1000);
             PDE.Address = (uint64_t)PT >> 12;
             PDE.Present = true;
             PDE.ReadWrite = true;

kernel/src/std/stdio.cpp

@@ -52,12 +52,12 @@ static int internal_printf(const char* format, PutString put_string_callback, ss
         {
             if (format_index + 1 == format_size) // end of format string
             {
+                format_index++;
                 continue;
             }
             else
             {
                 if (!preserve_format) format_index++;
-                else
                 preserve_format = false;
                 current_char = format[format_index];
                 switch (current_char)

tools/debug.sh

@@ -5,4 +5,4 @@ source $(dirname $0)/env.sh
 
 tools/build-iso.sh
 
-qemu-system-x86_64 -cdrom Luna.iso -smp 1 -m 256M -serial stdio -d int,cpu_reset -s
+qemu-system-x86_64 -cdrom Luna.iso -smp 1 -m 256M -serial stdio -d int,cpu_reset -s -no-reboot