Kernel: Enable basic paging

kernel/arch/i386/APIC.cpp

@@ -3,6 +3,7 @@
 #include <kernel/IDT.h>
 #include <kernel/IO.h>
 #include <kernel/kprint.h>
+#include <kernel/Paging.h>
 #include <kernel/panic.h>
 #include <kernel/PIC.h>
 #include <kernel/Serial.h>
@@ -210,6 +211,7 @@ namespace APIC
 	static void ParseMADT(RSDPDescriptor* rsdp)
 	{
 		RSDT* root = (RSDT*)(rsdp->revision == 2 ? ((RSDPDescriptor20*)rsdp)->xsdt_address : rsdp->rsdt_address);
+		Paging::MapRSDP((uint32_t)root & 0xFFC00000);
 		uint32_t sdt_entry_count = (root->header.length - sizeof(root->header)) / (rsdp->revision == 2 ? 8 : 4);
 
 		for (uint32_t i = 0; i < sdt_entry_count; i++)
@@ -370,6 +372,11 @@ namespace APIC
 		if (s_local_apic == 0 || s_io_apic == 0)
 			return false;
 
+		if ((s_io_apic & 0xFFC00000) != (s_local_apic & 0xFFC00000))
+			Kernel::panic("lapic and ioapic are not in the same 4 MiB are");
+		
+		Paging::MapAPIC(s_io_apic & 0xFFC00000);
+
 		// Enable Local APIC
 		SetMSR(IA32_APIC_BASE, (s_local_apic & 0xFFFFF000) | IA32_APIC_BASE_ENABLE, 0);
 

kernel/arch/i386/Paging.cpp

@@ -0,0 +1,73 @@
+#include <kernel/Paging.h>
+#include <kernel/panic.h>
+
+namespace Paging
+{
+
+	static uint32_t s_page_directory[1024] __attribute__((aligned(4096)));
+	static uint32_t s_page_table[1024] __attribute__((aligned(4096)));
+	static uint32_t s_page_table_framebuffer[1024] __attribute__((aligned(4096)));
+	static uint32_t s_page_table_rsdp[1024] __attribute__((aligned(4096)));
+	static uint32_t s_page_table_apic[1024] __attribute__((aligned(4096)));
+
+	void Initialize()
+	{
+		for (uint32_t i = 0; i < 1024; i++)
+			s_page_directory[i] = 0x00000002;
+
+		for (uint32_t i = 0; i < 1024; i++)
+			s_page_table[i] = (i << 12) | 0x03;
+		s_page_directory[0] = (uint32_t)s_page_table | 0x03;
+
+		asm volatile(
+			"movl %%eax, %%cr3;"
+			"movl %%cr0, %%eax;"
+			"orl $0x80000001, %%eax;"
+			"movl %%eax, %%cr0;"
+			:: "a"(s_page_directory)
+		);
+	}
+
+	void MapFramebuffer(uint32_t address)
+	{
+		uint32_t pd_index = address >> 22;
+
+		if (!(s_page_directory[pd_index] & (1 << 0)))
+		{
+			for (uint32_t i = 0; i < 1024; i++)
+				s_page_table_framebuffer[i] = address | (i << 12) | 0x03;
+			s_page_directory[pd_index] = (uint32_t)s_page_table_framebuffer | 0x03;
+			for (uint32_t i = 0; i < 1024; i++)
+				asm volatile("invlpg (%0)" :: "r" (address | (i << 12)) : "memory");
+		}
+	}
+
+	void MapRSDP(uint32_t address)
+	{
+		uint32_t pd_index = address >> 22;
+
+		if (!(s_page_directory[pd_index] & (1 << 0)))
+		{
+			for (uint32_t i = 0; i < 1024; i++)
+				s_page_table_rsdp[i] = address | (i << 12) | 0x03;
+			s_page_directory[pd_index] = (uint32_t)s_page_table_rsdp | 0x03;
+			for (uint32_t i = 0; i < 1024; i++)
+				asm volatile("invlpg (%0)" :: "r" (address | (i << 12)) : "memory");
+		}
+	}
+
+	void MapAPIC(uint32_t address)
+	{
+		uint32_t pd_index = address >> 22;
+
+		if (!(s_page_directory[pd_index] & (1 << 0)))
+		{
+			for (uint32_t i = 0; i < 1024; i++)
+				s_page_table_apic[i] = address | (i << 12) | 0x03;
+			s_page_directory[pd_index] = (uint32_t)s_page_table_apic | 0x03;
+			for (uint32_t i = 0; i < 1024; i++)
+				asm volatile("invlpg (%0)" :: "r" (address | (i << 12)) : "memory");
+		}
+	}
+
+}

kernel/arch/i386/VESA.cpp

@@ -1,6 +1,7 @@
 #include <kernel/IO.h>
 #include <kernel/kmalloc.h>
 #include <kernel/multiboot.h>
+#include <kernel/Paging.h>
 #include <kernel/panic.h>
 #include <kernel/Serial.h>
 #include <kernel/VESA.h>
@@ -82,6 +83,8 @@ namespace VESA
 		s_height	= framebuffer.height;
 		s_mode		= framebuffer.type;
 
+		Paging::MapFramebuffer(framebuffer.addr & 0xFFC00000);
+
 		if (s_mode == MULTIBOOT_FRAMEBUFFER_TYPE_GRAPHICS)
 		{
 			if (s_bpp != 24 && s_bpp != 32)

kernel/arch/i386/make.config

@@ -10,5 +10,6 @@ $(ARCHDIR)/CPUID.o		\
 $(ARCHDIR)/font.o		\
 $(ARCHDIR)/GDT.o		\
 $(ARCHDIR)/IDT.o		\
+$(ARCHDIR)/Paging.o		\
 $(ARCHDIR)/TTY.o		\
 $(ARCHDIR)/VESA.o		\

kernel/include/kernel/Paging.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <stdint.h>
+
+namespace Paging
+{
+
+	void Initialize();
+
+	void MapFramebuffer(uint32_t address);
+	void MapRSDP(uint32_t address);
+	void MapAPIC(uint32_t address);
+
+}

kernel/kernel/kernel.cpp

@@ -8,6 +8,7 @@
 #include <kernel/kmalloc.h>
 #include <kernel/kprint.h>
 #include <kernel/multiboot.h>
+#include <kernel/Paging.h>
 #include <kernel/panic.h>
 #include <kernel/PIC.h>
 #include <kernel/PIT.h>
@@ -50,6 +51,8 @@ extern "C" void kernel_main(multiboot_info_t* mbi, uint32_t magic)
 		return;
 	}
 
+	Paging::Initialize();
+
 	s_multiboot_info = mbi;
 
 	if (!VESA::Initialize())