From 0f3efdf25b5e5a1639be90af5e44ebd8e489ec06 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Sun, 19 Mar 2023 22:01:55 +0200
Subject: [PATCH 1/7] Test mb2

---
 Architecture/amd64/Bootstrap/MB2.asm          |  70 ++++
 Architecture/amd64/Bootstrap/MB2Detection.asm |  40 +++
 Architecture/amd64/Bootstrap/MB2Header.asm    |  42 +++
 Architecture/amd64/Bootstrap/MB2PageTable.asm |  14 +
 Architecture/amd64/Bootstrap/MB2Switch.asm    |   0
 Architecture/amd64/Bootstrap/Multiboot2.cpp   | 339 ++++++++++++++++++
 Architecture/amd64/linker.ld                  |  26 +-
 7 files changed, 523 insertions(+), 8 deletions(-)
 create mode 100644 Architecture/amd64/Bootstrap/MB2.asm
 create mode 100644 Architecture/amd64/Bootstrap/MB2Detection.asm
 create mode 100644 Architecture/amd64/Bootstrap/MB2Header.asm
 create mode 100644 Architecture/amd64/Bootstrap/MB2PageTable.asm
 create mode 100644 Architecture/amd64/Bootstrap/MB2Switch.asm
 create mode 100644 Architecture/amd64/Bootstrap/Multiboot2.cpp

diff --git a/Architecture/amd64/Bootstrap/MB2.asm b/Architecture/amd64/Bootstrap/MB2.asm
new file mode 100644
index 00000000..6b8fd55a
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/MB2.asm
@@ -0,0 +1,70 @@
+; https://wiki.osdev.org/Creating_a_64-bit_kernel
+; https://wiki.osdev.org/Entering_Long_Mode_Directly
+
+KERNEL_VIRTUAL_BASE equ 0xFFFFFFFF80000000 ; 512GB
+KERNEL_LMA equ 0x1000000 ; 16MB
+KERNEL_STACK_SIZE equ 0x4000 ; 16KB
+
+extern Multiboot2Entry
+extern BootPageTable
+extern DetectCPUID
+extern Detect64Bit
+global MB2_start
+
+[bits 32]
+section .text
+MB2_start:
+	cli
+
+    mov word [0xb8F00], 0x072E ; .
+
+	call DetectCPUID
+	call Detect64Bit
+
+	mov ecx, cr4
+	or ecx, 0x00000010 ; Set PSE in CR4
+	mov cr4, ecx
+
+    mov word [0xb8F02], 0x072E ; .
+
+	mov ecx, (BootPageTable - KERNEL_VIRTUAL_BASE)
+	mov cr3, ecx
+
+	mov ecx, cr0
+	or ecx, 0x80000000 ; Set PG in CR0
+	mov cr0, ecx
+
+	cli
+	hlt
+
+    mov word [0xb8F04], 0x072E ; .
+
+
+    mov word [0xb8F06], 0x072E ; .
+
+	cli
+	hlt
+
+	; lea ecx, [HigherHalfStart]
+	; jmp ecx
+
+[bits 64]
+HigherHalfStart:
+    mov word [0xb8F08], 0x072E ; .
+    mov dword [BootPageTable], 0
+    invlpg [0]
+
+	mov rsp, KernelStack + KERNEL_STACK_SIZE
+
+	push rax ; Multiboot2 Magic
+	add rbx, KERNEL_VIRTUAL_BASE
+	push rbx ; Multiboot2 Header
+	call Multiboot2Entry
+Loop:
+	hlt
+    jmp Loop
+
+section .bss
+align 16
+KernelStack: 
+	resb KERNEL_STACK_SIZE
diff --git a/Architecture/amd64/Bootstrap/MB2Detection.asm b/Architecture/amd64/Bootstrap/MB2Detection.asm
new file mode 100644
index 00000000..22ba2959
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/MB2Detection.asm
@@ -0,0 +1,40 @@
+[bits 32]
+global DetectCPUID
+DetectCPUID:
+    pushfd
+    pop eax
+    mov ecx, eax
+    xor eax, 1 << 21
+    push eax
+    popfd
+    pushfd
+    pop eax
+    push ecx
+    popfd
+    xor eax, ecx
+    jz .NoCPUID
+    ret
+.NoCPUID:
+    mov word [0xb8F00], 0xF00F ; .
+.Loop:
+    cli
+    hlt
+    jmp .Loop
+
+global Detect64Bit
+Detect64Bit:
+    mov eax, 0x80000000
+    cpuid
+    cmp eax, 0x80000001
+    jb .NoLongMode
+    mov eax, 0x80000001
+    cpuid
+    test edx, 1 << 29
+    jz .NoLongMode
+    ret
+.NoLongMode:
+    mov word [0xb8F00], 0xF00A ; .
+.Loop:
+    cli
+    hlt
+    jmp .Loop
diff --git a/Architecture/amd64/Bootstrap/MB2Header.asm b/Architecture/amd64/Bootstrap/MB2Header.asm
new file mode 100644
index 00000000..b05828df
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/MB2Header.asm
@@ -0,0 +1,42 @@
+[bits 32]
+section .multiboot2
+align 4096
+HEADER_START:
+    dd 0xE85250D6
+    dd 0
+    dd (HEADER_END - HEADER_START)
+    dd 0x100000000 - (HEADER_END - HEADER_START) - 0 - 0xE85250D6
+align 8
+MB2_INFO_REQUEST_TAG_START:
+    dw 1
+    dw 0
+    dd MB2_INFO_REQUEST_TAG_END - MB2_INFO_REQUEST_TAG_START
+    dd 1 ; Command Line
+    dd 2 ; Boot Loader Name
+    dd 3 ; Module
+    dd 4 ; Basic Memory Information
+    dd 5 ; BIOS Boot Device
+    dd 6 ; Memory Map
+    dd 7 ; VBE
+    dd 8 ; Framebuffer
+    dd 9 ; ELF Sections
+    dd 10 ; APM Table
+    dd 11 ; EFI 32-bit System Table Pointer
+    dd 12 ; EFI 64-bit System Table Pointer
+    ; dd 13 ; SMBIOS
+    dd 14 ; ACPI Old
+    dd 15 ; ACPI New
+    dd 16 ; Network
+    dd 17 ; EFI Memory Map
+    dd 18 ; EFI Boot Services Notifier
+    dd 19 ; EFI 32-bit Image Handle Pointer
+    dd 20 ; EFI 64-bit Image Handle Pointer
+    dd 21 ; Load Base Address
+MB2_INFO_REQUEST_TAG_END:
+align 8
+MB2_TAG_START:
+    dw 0
+    dw 0
+    dd MB2_TAG_END - MB2_TAG_START
+MB2_TAG_END:
+HEADER_END:
diff --git a/Architecture/amd64/Bootstrap/MB2PageTable.asm b/Architecture/amd64/Bootstrap/MB2PageTable.asm
new file mode 100644
index 00000000..4a66ac4b
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/MB2PageTable.asm
@@ -0,0 +1,14 @@
+%define KERNEL_OFFSET   0xFFFFFFFF80000000
+%define V2P(a) ((a) - KERNEL_OFFSET)
+
+%define PAGE_PRESENT    0x001
+%define PAGE_WRITE      0x002
+%define PAGE_GLOBAL     0x100
+
+%define PAGE_SIZE       0x1000
+%define ENTRIES_PER_PT  512
+
+section .data
+align PAGE_SIZE
+global BootPageTable
+BootPageTable:
diff --git a/Architecture/amd64/Bootstrap/MB2Switch.asm b/Architecture/amd64/Bootstrap/MB2Switch.asm
new file mode 100644
index 00000000..e69de29b
diff --git a/Architecture/amd64/Bootstrap/Multiboot2.cpp b/Architecture/amd64/Bootstrap/Multiboot2.cpp
new file mode 100644
index 00000000..99ed39a4
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/Multiboot2.cpp
@@ -0,0 +1,339 @@
+#include <types.h>
+
+#include <boot/protocols/multiboot2.h>
+#include <memory.hpp>
+#include <io.h>
+
+#include "../../../kernel.h"
+
+BootInfo mb2binfo;
+
+enum VideoType
+{
+    VIDEO_TYPE_NONE = 0x00,
+    VIDEO_TYPE_COLOUR = 0x20,
+    VIDEO_TYPE_MONOCHROME = 0x30,
+};
+
+uint16_t GetBiosAreaHardware()
+{
+    const uint16_t *BIOSDataAreaDetectedHardware = (const uint16_t *)0x410;
+    return *BIOSDataAreaDetectedHardware;
+}
+
+enum VideoType GetVideoType() { return (enum VideoType)(GetBiosAreaHardware() & 0x30); }
+
+void GetSMBIOS()
+{
+    unsigned char *SMBIOSAddress = (unsigned char *)0xF0000;
+    while ((unsigned int)(unsigned long)SMBIOSAddress < 0x100000)
+    {
+        if (SMBIOSAddress[0] == '_' &&
+            SMBIOSAddress[1] == 'S' &&
+            SMBIOSAddress[2] == 'M' &&
+            SMBIOSAddress[3] == '_')
+        {
+            unsigned char Checksum = 0;
+            int Length = SMBIOSAddress[5];
+            for (int i = 0; i < Length; i++)
+                Checksum += SMBIOSAddress[i];
+
+            if (Checksum == 0)
+                break;
+        }
+        SMBIOSAddress += 16;
+    }
+
+    if ((unsigned int)(unsigned long)SMBIOSAddress == 0x100000)
+    {
+        // No SMBIOS found
+    }
+}
+
+void ProcessMB2(unsigned long Info)
+{
+    uint8_t *VideoBuffer = (uint8_t *)0xB8F00 + 0xC0000000;
+    int pos = 0;
+    auto InfoAddress = Info;
+    for (auto Tag = (struct multiboot_tag *)((uint8_t *)InfoAddress + 8);
+         ;
+         Tag = (struct multiboot_tag *)((multiboot_uint8_t *)Tag + ((Tag->size + 7) & ~7)))
+    {
+        VideoBuffer[pos++] = '.';
+        VideoBuffer[pos++] = 0x2;
+
+        if (Tag->type == MULTIBOOT_TAG_TYPE_END)
+        {
+            debug("End of multiboot2 tags");
+            break;
+        }
+
+        switch (Tag->type)
+        {
+        case MULTIBOOT_TAG_TYPE_CMDLINE:
+        {
+            strncpy(mb2binfo.Kernel.CommandLine,
+                    ((multiboot_tag_string *)Tag)->string,
+                    strlen(((multiboot_tag_string *)Tag)->string));
+            debug("Kernel command line: %s", mb2binfo.Kernel.CommandLine);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME:
+        {
+            strncpy(mb2binfo.Bootloader.Name,
+                    ((multiboot_tag_string *)Tag)->string,
+                    strlen(((multiboot_tag_string *)Tag)->string));
+            debug("Bootloader name: %s", mb2binfo.Bootloader.Name);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_MODULE:
+        {
+            multiboot_tag_module *module = (multiboot_tag_module *)Tag;
+            static int module_count = 0;
+            mb2binfo.Modules[module_count++].Address = (void *)module->mod_start;
+            mb2binfo.Modules[module_count++].Size = module->size;
+            strncpy(mb2binfo.Modules[module_count++].Path, "(null)", 6);
+            strncpy(mb2binfo.Modules[module_count++].CommandLine, module->cmdline,
+                    strlen(module->cmdline));
+            debug("Module: %s", mb2binfo.Modules[module_count++].Path);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_BASIC_MEMINFO:
+        {
+            multiboot_tag_basic_meminfo *meminfo = (multiboot_tag_basic_meminfo *)Tag;
+            fixme("basic_meminfo->[mem_lower: %#x, mem_upper: %#x]",
+                  meminfo->mem_lower, meminfo->mem_upper);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_BOOTDEV:
+        {
+            multiboot_tag_bootdev *bootdev = (multiboot_tag_bootdev *)Tag;
+            fixme("bootdev->[biosdev: %#x, slice: %#x, part: %#x]",
+                  bootdev->biosdev, bootdev->slice, bootdev->part);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_MMAP:
+        {
+            multiboot_tag_mmap *mmap = (multiboot_tag_mmap *)Tag;
+            uint32_t EntryCount = mmap->size / sizeof(multiboot_mmap_entry);
+            mb2binfo.Memory.Entries = EntryCount;
+            for (uint32_t i = 0; i < EntryCount; i++)
+            {
+                if (EntryCount > MAX_MEMORY_ENTRIES)
+                {
+                    warn("Too many memory entries, skipping the rest...");
+                    break;
+                }
+                multiboot_mmap_entry entry = mmap->entries[i];
+                mb2binfo.Memory.Size += entry.len;
+                switch (entry.type)
+                {
+                case MULTIBOOT_MEMORY_AVAILABLE:
+                    mb2binfo.Memory.Entry[i].BaseAddress = (void *)entry.addr;
+                    mb2binfo.Memory.Entry[i].Length = entry.len;
+                    mb2binfo.Memory.Entry[i].Type = Usable;
+                    break;
+                case MULTIBOOT_MEMORY_RESERVED:
+                    mb2binfo.Memory.Entry[i].BaseAddress = (void *)entry.addr;
+                    mb2binfo.Memory.Entry[i].Length = entry.len;
+                    mb2binfo.Memory.Entry[i].Type = Reserved;
+                    break;
+                case MULTIBOOT_MEMORY_ACPI_RECLAIMABLE:
+                    mb2binfo.Memory.Entry[i].BaseAddress = (void *)entry.addr;
+                    mb2binfo.Memory.Entry[i].Length = entry.len;
+                    mb2binfo.Memory.Entry[i].Type = ACPIReclaimable;
+                    break;
+                case MULTIBOOT_MEMORY_NVS:
+                    mb2binfo.Memory.Entry[i].BaseAddress = (void *)entry.addr;
+                    mb2binfo.Memory.Entry[i].Length = entry.len;
+                    mb2binfo.Memory.Entry[i].Type = ACPINVS;
+                    break;
+                case MULTIBOOT_MEMORY_BADRAM:
+                    mb2binfo.Memory.Entry[i].BaseAddress = (void *)entry.addr;
+                    mb2binfo.Memory.Entry[i].Length = entry.len;
+                    mb2binfo.Memory.Entry[i].Type = BadMemory;
+                    break;
+                default:
+                    mb2binfo.Memory.Entry[i].BaseAddress = (void *)entry.addr;
+                    mb2binfo.Memory.Entry[i].Length = entry.len;
+                    mb2binfo.Memory.Entry[i].Type = Unknown;
+                    break;
+                }
+                debug("Memory entry: [BaseAddress: %#x, Length: %#x, Type: %d]",
+                      mb2binfo.Memory.Entry[i].BaseAddress,
+                      mb2binfo.Memory.Entry[i].Length,
+                      mb2binfo.Memory.Entry[i].Type);
+            }
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_VBE:
+        {
+            multiboot_tag_vbe *vbe = (multiboot_tag_vbe *)Tag;
+            fixme("vbe->[vbe_mode: %#x, vbe_interface_seg: %#x, vbe_interface_off: %#x, vbe_interface_len: %#x]",
+                  vbe->vbe_mode, vbe->vbe_interface_seg, vbe->vbe_interface_off, vbe->vbe_interface_len);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_FRAMEBUFFER:
+        {
+            multiboot_tag_framebuffer *fb = (multiboot_tag_framebuffer *)Tag;
+            static int fb_count = 0;
+            mb2binfo.Framebuffer[fb_count].BaseAddress = (void *)fb->common.framebuffer_addr;
+            mb2binfo.Framebuffer[fb_count].Width = fb->common.framebuffer_width;
+            mb2binfo.Framebuffer[fb_count].Height = fb->common.framebuffer_height;
+            mb2binfo.Framebuffer[fb_count].Pitch = fb->common.framebuffer_pitch;
+            mb2binfo.Framebuffer[fb_count].BitsPerPixel = fb->common.framebuffer_bpp;
+            mb2binfo.Framebuffer[fb_count].MemoryModel = fb->common.framebuffer_type;
+            switch (fb->common.framebuffer_type)
+            {
+            case MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED:
+            {
+                fixme("indexed");
+                break;
+            }
+            case MULTIBOOT_FRAMEBUFFER_TYPE_RGB:
+            {
+                mb2binfo.Framebuffer[fb_count].RedMaskSize = fb->framebuffer_red_mask_size;
+                mb2binfo.Framebuffer[fb_count].RedMaskShift = fb->framebuffer_red_field_position;
+                mb2binfo.Framebuffer[fb_count].GreenMaskSize = fb->framebuffer_green_mask_size;
+                mb2binfo.Framebuffer[fb_count].GreenMaskShift = fb->framebuffer_green_field_position;
+                mb2binfo.Framebuffer[fb_count].BlueMaskSize = fb->framebuffer_blue_mask_size;
+                mb2binfo.Framebuffer[fb_count].BlueMaskShift = fb->framebuffer_blue_field_position;
+                break;
+            }
+            case MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT:
+            {
+                fixme("ega_text");
+                break;
+            }
+            }
+            debug("Framebuffer %d: %dx%d %d bpp", Tag, fb->common.framebuffer_width, fb->common.framebuffer_height, fb->common.framebuffer_bpp);
+            debug("More info:\nAddress: %p\nPitch: %lld\nMemoryModel: %d\nRedMaskSize: %d\nRedMaskShift: %d\nGreenMaskSize: %d\nGreenMaskShift: %d\nBlueMaskSize: %d\nBlueMaskShift: %d",
+                  fb->common.framebuffer_addr, fb->common.framebuffer_pitch, fb->common.framebuffer_type,
+                  fb->framebuffer_red_mask_size, fb->framebuffer_red_field_position, fb->framebuffer_green_mask_size,
+                  fb->framebuffer_green_field_position, fb->framebuffer_blue_mask_size, fb->framebuffer_blue_field_position);
+            fb_count++;
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_ELF_SECTIONS:
+        {
+            multiboot_tag_elf_sections *elf = (multiboot_tag_elf_sections *)Tag;
+            fixme("elf_sections->[num=%d, size=%d, entsize=%d, shndx=%d]",
+                  elf->num, elf->size, elf->entsize, elf->shndx);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_APM:
+        {
+            multiboot_tag_apm *apm = (multiboot_tag_apm *)Tag;
+            fixme("apm->[version: %d, cseg: %d, offset: %d, cseg_16: %d, dseg: %d, flags: %d, cseg_len: %d, cseg_16_len: %d, dseg_len: %d]",
+                  apm->version, apm->cseg, apm->offset, apm->cseg_16, apm->dseg, apm->flags, apm->cseg_len, apm->cseg_16_len, apm->dseg_len);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_EFI32:
+        {
+            multiboot_tag_efi32 *efi32 = (multiboot_tag_efi32 *)Tag;
+            fixme("efi32->[pointer: %p, size: %d]", efi32->pointer, efi32->size);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_EFI64:
+        {
+            multiboot_tag_efi64 *efi64 = (multiboot_tag_efi64 *)Tag;
+            fixme("efi64->[pointer: %p, size: %d]", efi64->pointer, efi64->size);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_SMBIOS:
+        {
+            multiboot_tag_smbios *smbios = (multiboot_tag_smbios *)Tag;
+            fixme("smbios->[major: %d, minor: %d]", smbios->major, smbios->minor);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_ACPI_OLD:
+        {
+            mb2binfo.RSDP = (BootInfo::RSDPInfo *)((multiboot_tag_old_acpi *)Tag)->rsdp;
+            debug("OLD ACPI RSDP: %p", mb2binfo.RSDP);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_ACPI_NEW:
+        {
+            mb2binfo.RSDP = (BootInfo::RSDPInfo *)((multiboot_tag_new_acpi *)Tag)->rsdp;
+            debug("NEW ACPI RSDP: %p", mb2binfo.RSDP);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_NETWORK:
+        {
+            multiboot_tag_network *net = (multiboot_tag_network *)Tag;
+            fixme("network->[dhcpack: %p]", net->dhcpack);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_EFI_MMAP:
+        {
+            multiboot_tag_efi_mmap *efi_mmap = (multiboot_tag_efi_mmap *)Tag;
+            fixme("efi_mmap->[descr_size: %d, descr_vers: %d, efi_mmap: %p]",
+                  efi_mmap->descr_size, efi_mmap->descr_vers, efi_mmap->efi_mmap);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_EFI_BS:
+        {
+            fixme("efi_bs->[%p] (unknown structure)", Tag);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_EFI32_IH:
+        {
+            multiboot_tag_efi32_ih *efi32_ih = (multiboot_tag_efi32_ih *)Tag;
+            fixme("efi32_ih->[pointer: %p]", efi32_ih->pointer);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_EFI64_IH:
+        {
+            multiboot_tag_efi64_ih *efi64_ih = (multiboot_tag_efi64_ih *)Tag;
+            fixme("efi64_ih->[pointer: %p]", efi64_ih->pointer);
+            break;
+        }
+        case MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDR:
+        {
+            multiboot_tag_load_base_addr *load_base_addr = (multiboot_tag_load_base_addr *)Tag;
+            mb2binfo.Kernel.PhysicalBase = (void *)load_base_addr->load_base_addr;
+            mb2binfo.Kernel.VirtualBase = (void *)(load_base_addr->load_base_addr + 0xC0000000);
+            debug("Kernel base: %p (physical) %p (virtual)", mb2binfo.Kernel.PhysicalBase, mb2binfo.Kernel.VirtualBase);
+            break;
+        }
+        default:
+        {
+            error("Unknown multiboot2 tag type: %d", Tag->type);
+            break;
+        }
+        }
+    }
+}
+
+EXTERNC void Multiboot2Entry(unsigned long Info, unsigned int Magic)
+{
+    if (Info == NULL || Magic == NULL)
+    {
+        if (Magic == NULL)
+            error("Multiboot magic is NULL");
+        if (Info == NULL)
+            error("Multiboot info is NULL");
+        CPU::Stop();
+    }
+    else if (Magic != MULTIBOOT2_BOOTLOADER_MAGIC)
+    {
+        error("Multiboot magic is invalid (%#x != %#x)", Magic, MULTIBOOT2_BOOTLOADER_MAGIC);
+        CPU::Stop();
+    }
+
+    uint64_t div = 1193180 / 1000;
+    outb(0x43, 0xB6);
+    outb(0x42, (uint8_t)div);
+    outb(0x42, (uint8_t)(div >> 8));
+    uint8_t tmp = inb(0x61);
+    if (tmp != (tmp | 3))
+        outb(0x61, tmp | 3);
+
+    ProcessMB2(Info);
+
+    tmp = inb(0x61) & 0xFC;
+    outb(0x61, tmp);
+
+    CPU::Stop();
+    Entry(&mb2binfo);
+}
diff --git a/Architecture/amd64/linker.ld b/Architecture/amd64/linker.ld
index 357c4cdc..9407e8ba 100644
--- a/Architecture/amd64/linker.ld
+++ b/Architecture/amd64/linker.ld
@@ -1,35 +1,45 @@
 OUTPUT_FORMAT(elf64-x86-64)
 OUTPUT_ARCH(i386:x86-64)
 
-ENTRY(_start)
+KERNEL_LMA = 16M;
+KERNEL_VMA = 0xFFFFFFFF80000000;
+
+ENTRY(MB2_start)
 
 SECTIONS
 {
-    . = 0xffffffff80000000;
+    . = KERNEL_LMA;
+
+    .multiboot2 :
+    {
+        *(.multiboot2 .multiboot2.*)
+    }
+
+    . += KERNEL_VMA;
 
     _kernel_start = .;
-    .text :
+    .text : AT(ADDR(.text) - KERNEL_VMA)
     {
         *(.text .text.*)
     }
     _kernel_text_end = ALIGN(CONSTANT(MAXPAGESIZE));
     . += CONSTANT(MAXPAGESIZE);
 
-    .data :
+    .data : AT(ADDR(.data) - KERNEL_VMA)
     {
         *(.data .data.*)
     }
     _kernel_data_end = ALIGN(CONSTANT(MAXPAGESIZE));
     . += CONSTANT(MAXPAGESIZE);
 
-    .rodata :
+    .rodata : AT(ADDR(.rodata) - KERNEL_VMA)
     {
         *(.rodata .rodata.*)
     }
     _kernel_rodata_end = ALIGN(CONSTANT(MAXPAGESIZE));
     . += CONSTANT(MAXPAGESIZE);
 
-    .init_array :
+    .init_array : AT(ADDR(.init_array) - KERNEL_VMA)
     {
         PROVIDE_HIDDEN(__init_array_start = .);
         KEEP(*(.init_array .ctors))
@@ -37,7 +47,7 @@ SECTIONS
         PROVIDE_HIDDEN (__init_array_end = .);
     }
 
-    .fini_array :
+    .fini_array : AT(ADDR(.fini_array) - KERNEL_VMA)
     {
         PROVIDE_HIDDEN(__fini_array_start = .);
         KEEP(*(SORT_BY_INIT_PRIORITY(.fini_array.*) SORT_BY_INIT_PRIORITY(.dtors.*)))
@@ -46,7 +56,7 @@ SECTIONS
     }
     . += CONSTANT(MAXPAGESIZE);
 
-    .bss :
+    .bss : AT(ADDR(.bss) - KERNEL_VMA)
     {
         *(COMMON)
         *(.bss .bss.*)

From 8ff3623ee4cf199600208c6c0f57e1a1a90c7dd9 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Sun, 19 Mar 2023 21:59:38 +0200
Subject: [PATCH 2/7] Move bootloader code to a separate directory

---
 Architecture/amd64/{ => Bootstrap}/Limine.c   |   4 +-
 Architecture/amd64/runtime/crt1.c             |   1 -
 Architecture/i686/Bootstrap/MB2.asm           |  54 +++++++++
 Architecture/i686/Bootstrap/MB2Header.asm     |  41 +++++++
 Architecture/i686/Bootstrap/MB2PageTable.asm  |  13 +++
 .../i686/{ => Bootstrap}/Multiboot2.cpp       |   4 +-
 Architecture/i686/linker.ld                   |   2 +-
 Architecture/i686/runtime/crt1.asm            | 104 ------------------
 Architecture/i686/runtime/crt1.c              |  15 +++
 9 files changed, 128 insertions(+), 110 deletions(-)
 rename Architecture/amd64/{ => Bootstrap}/Limine.c (99%)
 create mode 100644 Architecture/i686/Bootstrap/MB2.asm
 create mode 100644 Architecture/i686/Bootstrap/MB2Header.asm
 create mode 100644 Architecture/i686/Bootstrap/MB2PageTable.asm
 rename Architecture/i686/{ => Bootstrap}/Multiboot2.cpp (99%)
 delete mode 100644 Architecture/i686/runtime/crt1.asm
 create mode 100644 Architecture/i686/runtime/crt1.c

diff --git a/Architecture/amd64/Limine.c b/Architecture/amd64/Bootstrap/Limine.c
similarity index 99%
rename from Architecture/amd64/Limine.c
rename to Architecture/amd64/Bootstrap/Limine.c
index 34566548..40acbfd3 100644
--- a/Architecture/amd64/Limine.c
+++ b/Architecture/amd64/Bootstrap/Limine.c
@@ -3,8 +3,8 @@
 #include <debug.h>
 #include <convert.h>
 
-#include "../../../tools/limine/limine.h"
-#include "../../kernel.h"
+#include "../../../../tools/limine/limine.h"
+#include "../../../kernel.h"
 
 void init_limine();
 
diff --git a/Architecture/amd64/runtime/crt1.c b/Architecture/amd64/runtime/crt1.c
index 17a6144c..bcc936a5 100644
--- a/Architecture/amd64/runtime/crt1.c
+++ b/Architecture/amd64/runtime/crt1.c
@@ -13,4 +13,3 @@ void _start(void *Raw)
     Entry(NULL);
     return;
 }
-// C stuff
\ No newline at end of file
diff --git a/Architecture/i686/Bootstrap/MB2.asm b/Architecture/i686/Bootstrap/MB2.asm
new file mode 100644
index 00000000..85d1c81f
--- /dev/null
+++ b/Architecture/i686/Bootstrap/MB2.asm
@@ -0,0 +1,54 @@
+; https://wiki.osdev.org/Higher_Half_x86_Bare_Bones
+; https://wiki.osdev.org/Higher_Half_x86_Bare_Bones_(Backup)
+
+KERNEL_VIRTUAL_BASE equ 0xC0000000 ; 3GB
+KERNEL_STACK_SIZE equ 0x4000 ; 16KB
+
+extern Multiboot2Entry
+extern BootPageTable
+global MB2_start
+
+section .text
+MB2_start:
+	cli
+    mov word [0xb8F00], 0x072E ; .
+
+	mov ecx, (BootPageTable - KERNEL_VIRTUAL_BASE)
+	mov cr3, ecx
+
+    mov word [0xb8F02], 0x072E ; .
+
+	mov ecx, cr4
+	or ecx, 0x00000010 ; Set PSE in CR4
+	mov cr4, ecx
+
+    mov word [0xb8F04], 0x072E ; .
+
+	mov ecx, cr0
+	or ecx, 0x80000000 ; Set PG in CR0
+	mov cr0, ecx
+
+    mov word [0xb8F06], 0x072E ; .
+
+	lea ecx, [HigherHalfStart]
+	jmp ecx
+
+HigherHalfStart:
+    mov word [0xb8F08], 0x072E ; .
+    mov dword [BootPageTable], 0
+    invlpg [0]
+
+	mov esp, KernelStack + KERNEL_STACK_SIZE
+
+	push eax ; Multiboot2 Magic
+	add ebx, KERNEL_VIRTUAL_BASE
+	push ebx ; Multiboot2 Header
+	call Multiboot2Entry
+Loop:
+	hlt
+    jmp Loop
+
+section .bss
+align 16
+KernelStack: 
+	resb KERNEL_STACK_SIZE
diff --git a/Architecture/i686/Bootstrap/MB2Header.asm b/Architecture/i686/Bootstrap/MB2Header.asm
new file mode 100644
index 00000000..a0a9a71e
--- /dev/null
+++ b/Architecture/i686/Bootstrap/MB2Header.asm
@@ -0,0 +1,41 @@
+section .multiboot2
+align 4096
+HEADER_START:
+    dd 0xE85250D6
+    dd 0
+    dd (HEADER_END - HEADER_START)
+    dd 0x100000000 - (HEADER_END - HEADER_START) - 0 - 0xE85250D6
+align 8
+MB2_INFO_REQUEST_TAG_START:
+    dw 1
+    dw 0
+    dd MB2_INFO_REQUEST_TAG_END - MB2_INFO_REQUEST_TAG_START
+    dd 1 ; Command Line
+    dd 2 ; Boot Loader Name
+    dd 3 ; Module
+    dd 4 ; Basic Memory Information
+    dd 5 ; BIOS Boot Device
+    dd 6 ; Memory Map
+    dd 7 ; VBE
+    dd 8 ; Framebuffer
+    dd 9 ; ELF Sections
+    dd 10 ; APM Table
+    dd 11 ; EFI 32-bit System Table Pointer
+    dd 12 ; EFI 64-bit System Table Pointer
+    ; dd 13 ; SMBIOS
+    dd 14 ; ACPI Old
+    dd 15 ; ACPI New
+    dd 16 ; Network
+    dd 17 ; EFI Memory Map
+    dd 18 ; EFI Boot Services Notifier
+    dd 19 ; EFI 32-bit Image Handle Pointer
+    dd 20 ; EFI 64-bit Image Handle Pointer
+    dd 21 ; Load Base Address
+MB2_INFO_REQUEST_TAG_END:
+align 8
+MB2_TAG_START:
+    dw 0
+    dw 0
+    dd MB2_TAG_END - MB2_TAG_START
+MB2_TAG_END:
+HEADER_END:
diff --git a/Architecture/i686/Bootstrap/MB2PageTable.asm b/Architecture/i686/Bootstrap/MB2PageTable.asm
new file mode 100644
index 00000000..9989867d
--- /dev/null
+++ b/Architecture/i686/Bootstrap/MB2PageTable.asm
@@ -0,0 +1,13 @@
+KERNEL_VIRTUAL_BASE equ 0xC0000000 ; 3GB
+KERNEL_PAGE_NUMBER equ (KERNEL_VIRTUAL_BASE >> 22) ; 768
+
+section .data
+global BootPageTable
+align 0x1000
+BootPageTable:
+    dd 0x00000083
+    dd 0x00000083
+    times (KERNEL_PAGE_NUMBER - 2) dd 0
+    dd 0x00000083
+    dd 0x00000083
+    times (1024 - KERNEL_PAGE_NUMBER - 2) dd 0
diff --git a/Architecture/i686/Multiboot2.cpp b/Architecture/i686/Bootstrap/Multiboot2.cpp
similarity index 99%
rename from Architecture/i686/Multiboot2.cpp
rename to Architecture/i686/Bootstrap/Multiboot2.cpp
index 0fe6fabb..99ed39a4 100644
--- a/Architecture/i686/Multiboot2.cpp
+++ b/Architecture/i686/Bootstrap/Multiboot2.cpp
@@ -4,7 +4,7 @@
 #include <memory.hpp>
 #include <io.h>
 
-#include "../../kernel.h"
+#include "../../../kernel.h"
 
 BootInfo mb2binfo;
 
@@ -305,7 +305,7 @@ void ProcessMB2(unsigned long Info)
     }
 }
 
-EXTERNC void x32Multiboot2Entry(unsigned long Info, unsigned int Magic)
+EXTERNC void Multiboot2Entry(unsigned long Info, unsigned int Magic)
 {
     if (Info == NULL || Magic == NULL)
     {
diff --git a/Architecture/i686/linker.ld b/Architecture/i686/linker.ld
index 1917158d..a1a6e947 100644
--- a/Architecture/i686/linker.ld
+++ b/Architecture/i686/linker.ld
@@ -1,7 +1,7 @@
 OUTPUT_FORMAT(elf32-i386)
 OUTPUT_ARCH(i386)
 
-ENTRY(_start)
+ENTRY(MB2_start)
 
 SECTIONS
 {
diff --git a/Architecture/i686/runtime/crt1.asm b/Architecture/i686/runtime/crt1.asm
deleted file mode 100644
index 42dddbc8..00000000
--- a/Architecture/i686/runtime/crt1.asm
+++ /dev/null
@@ -1,104 +0,0 @@
-; https://wiki.osdev.org/Higher_Half_x86_Bare_Bones
-; https://wiki.osdev.org/Higher_Half_x86_Bare_Bones_(Backup)
-section .multiboot2
-align 4096
-HEADER_START:
-    dd 0xE85250D6
-    dd 0
-    dd (HEADER_END - HEADER_START)
-    dd 0x100000000 - (HEADER_END - HEADER_START) - 0 - 0xE85250D6
-align 8
-MB2_INFO_REQUEST_TAG_START:
-    dw 1
-    dw 0
-    dd MB2_INFO_REQUEST_TAG_END - MB2_INFO_REQUEST_TAG_START
-    dd 1 ; Command Line
-    dd 2 ; Boot Loader Name
-    dd 3 ; Module
-    dd 4 ; Basic Memory Information
-    dd 5 ; BIOS Boot Device
-    dd 6 ; Memory Map
-    dd 7 ; VBE
-    dd 8 ; Framebuffer
-    dd 9 ; ELF Sections
-    dd 10 ; APM Table
-    dd 11 ; EFI 32-bit System Table Pointer
-    dd 12 ; EFI 64-bit System Table Pointer
-    ; dd 13 ; SMBIOS
-    dd 14 ; ACPI Old
-    dd 15 ; ACPI New
-    dd 16 ; Network
-    dd 17 ; EFI Memory Map
-    dd 18 ; EFI Boot Services Notifier
-    dd 19 ; EFI 32-bit Image Handle Pointer
-    dd 20 ; EFI 64-bit Image Handle Pointer
-    dd 21 ; Load Base Address
-MB2_INFO_REQUEST_TAG_END:
-align 8
-MB2_TAG_START:
-    dw 0
-    dw 0
-    dd MB2_TAG_END - MB2_TAG_START
-MB2_TAG_END:
-HEADER_END:
-
-KERNEL_VIRTUAL_BASE equ 0xC0000000 ; 3GB
-KERNEL_PAGE_NUMBER equ (KERNEL_VIRTUAL_BASE >> 22) ; 768
-KERNEL_STACK_SIZE equ 0x4000 ; 16KB
-
-extern x32Multiboot2Entry
-global _start
-
-section .data
-align 0x1000
-BootPageTable:
-    dd 0x00000083
-    dd 0x00000083
-    times (KERNEL_PAGE_NUMBER - 2) dd 0
-    dd 0x00000083
-    dd 0x00000083
-    times (1024 - KERNEL_PAGE_NUMBER - 2) dd 0
-
-section .text
-_start:
-    mov word [0xb8F00], 0x072E ; .
-
-	mov ecx, (BootPageTable - KERNEL_VIRTUAL_BASE)
-	mov cr3, ecx
-
-    mov word [0xb8F02], 0x072E ; .
-
-	mov ecx, cr4
-	or ecx, 0x00000010 ; Set PSE in CR4
-	mov cr4, ecx
-
-    mov word [0xb8F04], 0x072E ; .
-
-	mov ecx, cr0
-	or ecx, 0x80000000 ; Set PG in CR0
-	mov cr0, ecx
-
-    mov word [0xb8F06], 0x072E ; .
-
-	lea ecx, [HigherHalfStart]
-	jmp ecx
-
-HigherHalfStart:
-    mov word [0xb8F08], 0x072E ; .
-    mov dword [BootPageTable], 0
-    invlpg [0]
-
-	mov esp, KernelStack + KERNEL_STACK_SIZE
-
-	push eax ; Multiboot2 Magic
-	add ebx, KERNEL_VIRTUAL_BASE
-	push ebx ; Multiboot2 Header
-	call x32Multiboot2Entry
-Loop:
-	hlt
-    jmp Loop
-
-section .bss
-align 16
-KernelStack : 
-	resb KERNEL_STACK_SIZE
diff --git a/Architecture/i686/runtime/crt1.c b/Architecture/i686/runtime/crt1.c
new file mode 100644
index 00000000..bcc936a5
--- /dev/null
+++ b/Architecture/i686/runtime/crt1.c
@@ -0,0 +1,15 @@
+#include <types.h>
+
+#include <debug.h>
+
+int Entry(void *Info);
+
+void _start(void *Raw)
+{
+    UNUSED(Raw);
+    error("ERROR! INVALID BOOT PROTOCOL!");
+    while (1)
+        asmv("hlt");
+    Entry(NULL);
+    return;
+}

From 298c6b392193e762b8764346599be9c72717e318 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Sun, 19 Mar 2023 22:14:11 +0200
Subject: [PATCH 3/7] Update page table code

---
 Architecture/amd64/Bootstrap/MB2PageTable.asm | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/Architecture/amd64/Bootstrap/MB2PageTable.asm b/Architecture/amd64/Bootstrap/MB2PageTable.asm
index 4a66ac4b..16c0d867 100644
--- a/Architecture/amd64/Bootstrap/MB2PageTable.asm
+++ b/Architecture/amd64/Bootstrap/MB2PageTable.asm
@@ -1,14 +1,10 @@
-%define KERNEL_OFFSET   0xFFFFFFFF80000000
-%define V2P(a) ((a) - KERNEL_OFFSET)
-
-%define PAGE_PRESENT    0x001
-%define PAGE_WRITE      0x002
-%define PAGE_GLOBAL     0x100
-
-%define PAGE_SIZE       0x1000
-%define ENTRIES_PER_PT  512
-
 section .data
-align PAGE_SIZE
+align 0x1000
 global BootPageTable
 BootPageTable:
+    dq 0x0000000000000083
+    dq 0x0000000000000083
+    TIMES (512-2) dq 0
+    dq 0x0000000000000083
+    dq 0x0000000000000083
+    TIMES (512-2) dq 0
\ No newline at end of file

From 73f38799ebf26ff56c55843c6734bfa17a6b2399 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Wed, 29 Mar 2023 10:56:23 +0300
Subject: [PATCH 4/7] Update multiboot2 bootstrap code

---
 Architecture/amd64/Bootstrap/MB2.asm          |  70 ---------
 Architecture/amd64/Bootstrap/MB2PageTable.asm |  10 --
 Architecture/amd64/Bootstrap/MB2Switch.asm    |   0
 .../Detection.asm}                            |   1 +
 .../amd64/Bootstrap/Multiboot2/Entry.asm      | 139 ++++++++++++++++++
 .../amd64/Bootstrap/Multiboot2/GDT32.asm      |  47 ++++++
 .../{MB2Header.asm => Multiboot2/Header.asm}  |   0
 .../Bootstrap/{ => Multiboot2}/Multiboot2.cpp |   2 +-
 .../amd64/Bootstrap/Multiboot2/PageTable.asm  |  85 +++++++++++
 Architecture/amd64/linker.ld                  |   8 +
 10 files changed, 281 insertions(+), 81 deletions(-)
 delete mode 100644 Architecture/amd64/Bootstrap/MB2.asm
 delete mode 100644 Architecture/amd64/Bootstrap/MB2PageTable.asm
 delete mode 100644 Architecture/amd64/Bootstrap/MB2Switch.asm
 rename Architecture/amd64/Bootstrap/{MB2Detection.asm => Multiboot2/Detection.asm} (95%)
 create mode 100644 Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
 create mode 100644 Architecture/amd64/Bootstrap/Multiboot2/GDT32.asm
 rename Architecture/amd64/Bootstrap/{MB2Header.asm => Multiboot2/Header.asm} (100%)
 rename Architecture/amd64/Bootstrap/{ => Multiboot2}/Multiboot2.cpp (99%)
 create mode 100644 Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm

diff --git a/Architecture/amd64/Bootstrap/MB2.asm b/Architecture/amd64/Bootstrap/MB2.asm
deleted file mode 100644
index 6b8fd55a..00000000
--- a/Architecture/amd64/Bootstrap/MB2.asm
+++ /dev/null
@@ -1,70 +0,0 @@
-; https://wiki.osdev.org/Creating_a_64-bit_kernel
-; https://wiki.osdev.org/Entering_Long_Mode_Directly
-
-KERNEL_VIRTUAL_BASE equ 0xFFFFFFFF80000000 ; 512GB
-KERNEL_LMA equ 0x1000000 ; 16MB
-KERNEL_STACK_SIZE equ 0x4000 ; 16KB
-
-extern Multiboot2Entry
-extern BootPageTable
-extern DetectCPUID
-extern Detect64Bit
-global MB2_start
-
-[bits 32]
-section .text
-MB2_start:
-	cli
-
-    mov word [0xb8F00], 0x072E ; .
-
-	call DetectCPUID
-	call Detect64Bit
-
-	mov ecx, cr4
-	or ecx, 0x00000010 ; Set PSE in CR4
-	mov cr4, ecx
-
-    mov word [0xb8F02], 0x072E ; .
-
-	mov ecx, (BootPageTable - KERNEL_VIRTUAL_BASE)
-	mov cr3, ecx
-
-	mov ecx, cr0
-	or ecx, 0x80000000 ; Set PG in CR0
-	mov cr0, ecx
-
-	cli
-	hlt
-
-    mov word [0xb8F04], 0x072E ; .
-
-
-    mov word [0xb8F06], 0x072E ; .
-
-	cli
-	hlt
-
-	; lea ecx, [HigherHalfStart]
-	; jmp ecx
-
-[bits 64]
-HigherHalfStart:
-    mov word [0xb8F08], 0x072E ; .
-    mov dword [BootPageTable], 0
-    invlpg [0]
-
-	mov rsp, KernelStack + KERNEL_STACK_SIZE
-
-	push rax ; Multiboot2 Magic
-	add rbx, KERNEL_VIRTUAL_BASE
-	push rbx ; Multiboot2 Header
-	call Multiboot2Entry
-Loop:
-	hlt
-    jmp Loop
-
-section .bss
-align 16
-KernelStack: 
-	resb KERNEL_STACK_SIZE
diff --git a/Architecture/amd64/Bootstrap/MB2PageTable.asm b/Architecture/amd64/Bootstrap/MB2PageTable.asm
deleted file mode 100644
index 16c0d867..00000000
--- a/Architecture/amd64/Bootstrap/MB2PageTable.asm
+++ /dev/null
@@ -1,10 +0,0 @@
-section .data
-align 0x1000
-global BootPageTable
-BootPageTable:
-    dq 0x0000000000000083
-    dq 0x0000000000000083
-    TIMES (512-2) dq 0
-    dq 0x0000000000000083
-    dq 0x0000000000000083
-    TIMES (512-2) dq 0
\ No newline at end of file
diff --git a/Architecture/amd64/Bootstrap/MB2Switch.asm b/Architecture/amd64/Bootstrap/MB2Switch.asm
deleted file mode 100644
index e69de29b..00000000
diff --git a/Architecture/amd64/Bootstrap/MB2Detection.asm b/Architecture/amd64/Bootstrap/Multiboot2/Detection.asm
similarity index 95%
rename from Architecture/amd64/Bootstrap/MB2Detection.asm
rename to Architecture/amd64/Bootstrap/Multiboot2/Detection.asm
index 22ba2959..ee6166a7 100644
--- a/Architecture/amd64/Bootstrap/MB2Detection.asm
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Detection.asm
@@ -1,4 +1,5 @@
 [bits 32]
+section .bootstrap.text
 global DetectCPUID
 DetectCPUID:
     pushfd
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm b/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
new file mode 100644
index 00000000..ddcf1df6
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
@@ -0,0 +1,139 @@
+; https://wiki.osdev.org/Creating_a_64-bit_kernel
+; https://wiki.osdev.org/Entering_Long_Mode_Directly
+
+KERNEL_VIRTUAL_BASE equ 0xFFFFFFFF80000000 ; 512GB
+KERNEL_LMA equ 0x1000000 ; 16MB
+KERNEL_STACK_SIZE equ 0x4000 ; 16KB
+
+extern Multiboot2Entry
+extern BootPageTable
+extern UpdatePageTable
+extern UpdatePageTable64
+extern DetectCPUID
+extern Detect64Bit
+extern LoadGDT32
+global MB2_start
+extern MB2_start_c
+
+[bits 32]
+section .bootstrap.text
+MB2_start:
+	cli
+	mov word [0xb8F00], 0x072E ; .
+
+	; We need to check if the CPU supports 64-bit mode
+	call DetectCPUID
+	call Detect64Bit
+
+	mov word [0xb8F02], 0x072E ; .
+
+	mov ecx, cr0
+	and ecx, 0x7fffffff ; Clear PG
+	mov cr0, ecx
+
+	mov ecx, cr4
+	or ecx, 0x10 ; Set PSE
+	or ecx, 0x20 ; Set PAE
+	mov cr4, ecx
+
+	; Load the GDT and update the page table
+	call LoadGDT32
+	call UpdatePageTable
+
+	; Load the new page table
+	mov edi, BootPageTable
+	mov cr3, edi
+
+	mov word [0xb8F04], 0x072E ; .
+
+	; Enable long mode
+	mov ecx, 0xC0000080 ; EFER
+	rdmsr
+	or eax, 0x800 | 0x100 | 0x1 ; Set LME, LMA, SCE
+	wrmsr
+
+	mov ecx, cr0
+	or ecx, (0x80000000 | 0x1) ; Set PG and PE
+	mov cr0, ecx
+
+
+	lgdt [GDT64.Ptr]
+    ; xor eax, eax
+    ; sgdt [eax]
+    ; test eax, eax
+    ; jz .InvalidGDT
+
+	; .InvalidGDT:
+	; 	mov word [0xb8F07], 0x4 ; Red
+	; 	hlt
+
+	jmp GDT64.code:HigherHalfStart
+
+[bits 64]
+HigherHalfStart:
+	cli
+	mov word [0xb8F06], 0x072E ; .
+	call UpdatePageTable64
+
+	; Load the new page table
+	mov rdi, BootPageTable
+	mov cr3, rdi
+
+	mov ax, GDT64.data
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	mov ss, ax
+
+	mov word [0xb8F08], 0x072E ; .
+	mov rsp, (KernelStack + KERNEL_STACK_SIZE)
+
+	push rax ; Multiboot2 Magic
+	add rbx, KERNEL_VIRTUAL_BASE
+	push rbx ; Multiboot2 Header
+	call Multiboot2Entry
+	.Loop:
+		hlt
+		jmp .Loop
+
+section .bootstrap.bss
+align 16
+KernelStack: 
+	resb KERNEL_STACK_SIZE
+
+; Access bits
+PRESENT equ 1 << 7
+NOT_SYS equ 1 << 4
+EXEC equ 1 << 3
+DC equ 1 << 2
+RW equ 1 << 1
+ACCESSED equ 1 << 0
+ 
+; Flags bits
+GRAN_4K equ 1 << 7
+SZ_32 equ 1 << 6
+LONG_MODE equ 1 << 5
+
+section .bootstrap.data
+GDT64:
+    .null: equ $ - GDT64
+        dq 0
+    .code: equ $ - GDT64
+        dd 0xFFFF
+        db 0
+        db PRESENT | NOT_SYS | EXEC | RW
+        db GRAN_4K | LONG_MODE | 0xF
+        db 0
+    .data: equ $ - GDT64
+        dd 0xFFFF
+        db 0
+        db PRESENT | NOT_SYS | RW
+        db GRAN_4K | SZ_32 | 0xF
+        db 0
+    .tss: equ $ - GDT64
+        dd 0x00000068
+        dd 0x00CF8900
+	.Ptr:
+		dw $ - GDT64 - 1
+		dq GDT64
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/GDT32.asm b/Architecture/amd64/Bootstrap/Multiboot2/GDT32.asm
new file mode 100644
index 00000000..e9fa9804
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/Multiboot2/GDT32.asm
@@ -0,0 +1,47 @@
+[bits 32]
+section .bootstrap.text
+
+align 32
+global gdtr
+gdtr:
+    dw GDT32_END - GDT32 - 1
+    dd GDT32
+
+align 32
+GDT32:
+    dq 0x0
+
+    dw 0xffff
+    dw 0x0000
+    db 0x00
+    dw 0xcf9a
+    db 0x00
+
+    dw 0xffff
+    dw 0x0000
+    db 0x00
+    dw 0xcf92
+    db 0x00
+
+    dw 0x0100
+    dw 0x1000
+    db 0x00
+    dw 0x4092
+    db 0x00
+GDT32_END:
+
+global LoadGDT32
+LoadGDT32:
+	lgdt [gdtr]
+
+	jmp 0x8:ActivateGDT
+	ActivateGDT:
+		mov cx, 0x10
+		mov ss, cx
+		mov ds, cx
+		mov es, cx
+		mov fs, cx
+		mov cx, 0x18
+		mov gs, cx
+
+    ret
diff --git a/Architecture/amd64/Bootstrap/MB2Header.asm b/Architecture/amd64/Bootstrap/Multiboot2/Header.asm
similarity index 100%
rename from Architecture/amd64/Bootstrap/MB2Header.asm
rename to Architecture/amd64/Bootstrap/Multiboot2/Header.asm
diff --git a/Architecture/amd64/Bootstrap/Multiboot2.cpp b/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
similarity index 99%
rename from Architecture/amd64/Bootstrap/Multiboot2.cpp
rename to Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
index 99ed39a4..f85ac3b0 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2.cpp
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
@@ -4,7 +4,7 @@
 #include <memory.hpp>
 #include <io.h>
 
-#include "../../../kernel.h"
+#include "../../../../kernel.h"
 
 BootInfo mb2binfo;
 
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm b/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm
new file mode 100644
index 00000000..f6525d54
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm
@@ -0,0 +1,85 @@
+PAGE_TABLE_SIZE equ 0x4 ; 1GB
+[bits 32]
+
+section .bootstrap.data
+align 0x1000
+global BootPageTable
+BootPageTable:
+    times (0x10000) dq 0 ; 0x4000
+
+section .bootstrap.text
+global UpdatePageTable
+UpdatePageTable:
+	mov edi, (BootPageTable + 0x0000)
+
+	mov eax, (BootPageTable + 0x1000)
+	or eax, 0x3
+	mov dword [edi], eax
+
+	mov ecx, PAGE_TABLE_SIZE
+	mov edi, (BootPageTable + 0x1000)
+	mov eax, (BootPageTable + 0x2000)
+	or eax, 0x3
+	mov ebx, 0x0
+
+	.FillPageTableLevel3:
+		mov dword [edi], eax
+		mov dword [edi + 4], ebx
+		add eax, 1 << 12
+		adc ebx, 0
+		add edi, 8
+		loop .FillPageTableLevel3
+
+	mov ecx, (512 * PAGE_TABLE_SIZE)
+	mov edi, (BootPageTable + 0x2000)
+	mov eax, 0x0 | 0x3 | 1 << 7
+	mov ebx, 0x0
+
+	.FillPageTableLevel2:
+		mov dword [edi], eax
+		mov dword [edi + 4], ebx
+		add eax, 1 << 21
+		adc ebx, 0
+		add edi, 8
+		loop .FillPageTableLevel2
+
+	ret
+
+[bits 64]
+section .bootstrap.text
+global UpdatePageTable64
+UpdatePageTable64:
+	mov rdi, (BootPageTable + 0x0000)
+
+	mov rax, (BootPageTable + 0x1000)
+	or rax, 0x3
+	mov [rdi], rax
+
+	mov rcx, PAGE_TABLE_SIZE
+	mov rdi, (BootPageTable + 0x1000)
+	mov rax, (BootPageTable + 0x2000)
+	or rax, 0x3
+	mov rbx, 0x0
+
+	.FillPageTableLevel3:
+		mov [rdi], rax
+		mov [rdi + 4], rbx
+		add rax, 1 << 12
+		adc rbx, 0
+		add rdi, 8
+		loop .FillPageTableLevel3
+
+	mov rcx, (512 * PAGE_TABLE_SIZE)
+	mov rdi, (BootPageTable + 0x2000)
+	mov rax, 0x0 | 0x3 | 1 << 7
+	mov rbx, 0x0
+
+	.FillPageTableLevel2:
+		mov [rdi], rax
+		mov [rdi + 4], rbx
+		add rax, 1 << 21
+		adc rbx, 0
+		add rdi, 8
+		loop .FillPageTableLevel2
+
+	ret
diff --git a/Architecture/amd64/linker.ld b/Architecture/amd64/linker.ld
index 9407e8ba..96e0e549 100644
--- a/Architecture/amd64/linker.ld
+++ b/Architecture/amd64/linker.ld
@@ -15,6 +15,14 @@ SECTIONS
         *(.multiboot2 .multiboot2.*)
     }
 
+    .bootstrap :
+    {
+        *(.bootstrap.text .bootstrap.text.*)
+        *(.bootstrap.data .bootstrap.data.*)
+        *(.bootstrap.rodata .bootstrap.rodata.*)
+        *(.bootstrap.bss .bootstrap.bss.*)
+    }
+
     . += KERNEL_VMA;
 
     _kernel_start = .;

From b6f9a644a780fda73e0f6f9c6bf3518abd01bba2 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Thu, 30 Mar 2023 19:21:14 +0300
Subject: [PATCH 5/7] Map the kernel too

---
 .../amd64/Bootstrap/Multiboot2/Entry.asm      |  19 +-
 .../Bootstrap/Multiboot2/MB2MemoryMapper.cpp  | 281 ++++++++++++++++++
 .../amd64/Bootstrap/Multiboot2/Multiboot2.cpp |  75 +++--
 .../amd64/Bootstrap/Multiboot2/PageTable.asm  |  90 ++----
 Core/Memory/Memory.cpp                        |   4 +-
 include/boot/binfo.h                          |  14 +-
 6 files changed, 373 insertions(+), 110 deletions(-)
 create mode 100644 Architecture/amd64/Bootstrap/Multiboot2/MB2MemoryMapper.cpp

diff --git a/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm b/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
index ddcf1df6..6c7c0d95 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
@@ -16,10 +16,22 @@ global MB2_start
 extern MB2_start_c
 
 [bits 32]
+
+section .bootstrap.data
+global MB2_HeaderMagic
+MB2_HeaderMagic:
+    times (0x64) dq 0
+
+global MB2_HeaderInfo
+MB2_HeaderInfo:
+	times (0x64) dq 0
+
 section .bootstrap.text
 MB2_start:
 	cli
 	mov word [0xb8F00], 0x072E ; .
+    mov [MB2_HeaderMagic], eax
+    mov [MB2_HeaderInfo], ebx
 
 	; We need to check if the CPU supports 64-bit mode
 	call DetectCPUID
@@ -88,10 +100,11 @@ HigherHalfStart:
 
 	mov word [0xb8F08], 0x072E ; .
 	mov rsp, (KernelStack + KERNEL_STACK_SIZE)
+	mov rbp, (KernelStack + KERNEL_STACK_SIZE)
+
+	cld
+	cli
 
-	push rax ; Multiboot2 Magic
-	add rbx, KERNEL_VIRTUAL_BASE
-	push rbx ; Multiboot2 Header
 	call Multiboot2Entry
 	.Loop:
 		hlt
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/MB2MemoryMapper.cpp b/Architecture/amd64/Bootstrap/Multiboot2/MB2MemoryMapper.cpp
new file mode 100644
index 00000000..a128b496
--- /dev/null
+++ b/Architecture/amd64/Bootstrap/Multiboot2/MB2MemoryMapper.cpp
@@ -0,0 +1,281 @@
+#include <types.h>
+
+union __attribute__((packed)) PageTableEntry
+{
+    struct
+    {
+        bool Present : 1;            // 0
+        bool ReadWrite : 1;          // 1
+        bool UserSupervisor : 1;     // 2
+        bool WriteThrough : 1;       // 3
+        bool CacheDisable : 1;       // 4
+        bool Accessed : 1;           // 5
+        bool Dirty : 1;              // 6
+        bool PageAttributeTable : 1; // 7
+        bool Global : 1;             // 8
+        uint8_t Available0 : 3;      // 9-11
+        uint64_t Address : 40;       // 12-51
+        uint32_t Available1 : 7;     // 52-58
+        uint8_t ProtectionKey : 4;   // 59-62
+        bool ExecuteDisable : 1;     // 63
+    };
+    uint64_t raw;
+
+    __always_inline inline SafeFunction NIF void SetAddress(uintptr_t _Address)
+    {
+        _Address &= 0x000000FFFFFFFFFF;
+        this->raw &= 0xFFF0000000000FFF;
+        this->raw |= (_Address << 12);
+    }
+
+    __always_inline inline SafeFunction NIF uintptr_t GetAddress() { return (this->raw & 0x000FFFFFFFFFF000) >> 12; }
+};
+
+struct __attribute__((packed)) PageTableEntryPtr
+{
+    PageTableEntry Entries[511];
+};
+
+union __attribute__((packed)) PageDirectoryEntry
+{
+    struct
+    {
+        bool Present : 1;         // 0
+        bool ReadWrite : 1;       // 1
+        bool UserSupervisor : 1;  // 2
+        bool WriteThrough : 1;    // 3
+        bool CacheDisable : 1;    // 4
+        bool Accessed : 1;        // 5
+        bool Available0 : 1;      // 6
+        bool PageSize : 1;        // 7
+        uint8_t Available1 : 4;   // 8-11
+        uint64_t Address : 40;    // 12-51
+        uint32_t Available2 : 11; // 52-62
+        bool ExecuteDisable : 1;  // 63
+    };
+    uint64_t raw;
+
+    __always_inline inline SafeFunction NIF void SetAddress(uintptr_t _Address)
+    {
+        _Address &= 0x000000FFFFFFFFFF;
+        this->raw &= 0xFFF0000000000FFF;
+        this->raw |= (_Address << 12);
+    }
+
+    __always_inline inline SafeFunction NIF uintptr_t GetAddress() { return (this->raw & 0x000FFFFFFFFFF000) >> 12; }
+};
+
+struct __attribute__((packed)) PageDirectoryEntryPtr
+{
+    PageDirectoryEntry Entries[511];
+};
+
+union __attribute__((packed)) PageDirectoryPointerTableEntry
+{
+    struct
+    {
+        bool Present : 1;         // 0
+        bool ReadWrite : 1;       // 1
+        bool UserSupervisor : 1;  // 2
+        bool WriteThrough : 1;    // 3
+        bool CacheDisable : 1;    // 4
+        bool Accessed : 1;        // 5
+        bool Available0 : 1;      // 6
+        bool PageSize : 1;        // 7
+        uint8_t Available1 : 4;   // 8-11
+        uint64_t Address : 40;    // 12-51
+        uint32_t Available2 : 11; // 52-62
+        bool ExecuteDisable : 1;  // 63
+    };
+    uint64_t raw;
+
+    __always_inline inline SafeFunction NIF void SetAddress(uintptr_t _Address)
+    {
+        _Address &= 0x000000FFFFFFFFFF;
+        this->raw &= 0xFFF0000000000FFF;
+        this->raw |= (_Address << 12);
+    }
+
+    __always_inline inline SafeFunction NIF uintptr_t GetAddress() { return (this->raw & 0x000FFFFFFFFFF000) >> 12; }
+};
+
+struct __attribute__((packed)) PageDirectoryPointerTableEntryPtr
+{
+    PageDirectoryPointerTableEntry Entries[511];
+};
+
+union __attribute__((packed)) PageMapLevel4
+{
+    struct
+    {
+        bool Present : 1;         // 0
+        bool ReadWrite : 1;       // 1
+        bool UserSupervisor : 1;  // 2
+        bool WriteThrough : 1;    // 3
+        bool CacheDisable : 1;    // 4
+        bool Accessed : 1;        // 5
+        bool Available0 : 1;      // 6
+        bool Reserved0 : 1;       // 7
+        uint8_t Available1 : 4;   // 8-11
+        uint64_t Address : 40;    // 12-51
+        uint32_t Available2 : 11; // 52-62
+        bool ExecuteDisable : 1;  // 63
+    };
+    uint64_t raw;
+
+    __always_inline inline SafeFunction NIF void SetAddress(uintptr_t _Address)
+    {
+        _Address &= 0x000000FFFFFFFFFF;
+        this->raw &= 0xFFF0000000000FFF;
+        this->raw |= (_Address << 12);
+    }
+
+    __always_inline inline SafeFunction NIF uintptr_t GetAddress() { return (this->raw & 0x000FFFFFFFFFF000) >> 12; }
+};
+
+struct PageTable4
+{
+    PageMapLevel4 Entries[511];
+} __attribute__((aligned(0x1000)));
+
+extern "C" char BootPageTable[];
+extern uintptr_t _kernel_start, _kernel_end;
+
+__attribute__((section(".bootstrap.data"))) static PageTable4 *BPTable = (PageTable4 *)BootPageTable;
+__attribute__((section(".bootstrap.data"))) static size_t BPT_Allocated = 0x4000;
+
+__always_inline inline SafeFunction NIF void *RequestPage()
+{
+    void *Page = (void *)(BootPageTable + BPT_Allocated);
+    BPT_Allocated += 0x1000;
+    if (BPT_Allocated >= 0x10000) /* The length of BootPageTable */
+    {
+        while (true)
+            ;
+    }
+    return Page;
+}
+
+class PageMapIndexer
+{
+public:
+    uintptr_t PMLIndex = 0;
+    uintptr_t PDPTEIndex = 0;
+    uintptr_t PDEIndex = 0;
+    uintptr_t PTEIndex = 0;
+    __always_inline inline SafeFunction NIF PageMapIndexer(uintptr_t VirtualAddress)
+    {
+        uintptr_t Address = VirtualAddress;
+        Address >>= 12;
+        this->PTEIndex = Address & 0x1FF;
+        Address >>= 9;
+        this->PDEIndex = Address & 0x1FF;
+        Address >>= 9;
+        this->PDPTEIndex = Address & 0x1FF;
+        Address >>= 9;
+        this->PMLIndex = Address & 0x1FF;
+    }
+};
+
+__always_inline inline SafeFunction NIF void Map(void *VirtualAddress, void *PhysicalAddress, uint64_t Flags)
+{
+    PageMapIndexer Index = PageMapIndexer((uintptr_t)VirtualAddress);
+    // Clear any flags that are not 1 << 0 (Present) - 1 << 5 (Accessed) because rest are for page table entries only
+    uint64_t DirectoryFlags = Flags & 0x3F;
+
+    PageMapLevel4 PML4 = BPTable->Entries[Index.PMLIndex];
+    PageDirectoryPointerTableEntryPtr *PDPTEPtr = nullptr;
+    if (!PML4.Present)
+    {
+        PDPTEPtr = (PageDirectoryPointerTableEntryPtr *)RequestPage();
+        {
+            void *ptr = PDPTEPtr;
+            int value = 0;
+            size_t num = 0x1000;
+            uint8_t *p = (uint8_t *)ptr;
+            for (size_t i = 0; i < num; i++)
+                p[i] = value;
+        }
+        PML4.Present = true;
+        PML4.SetAddress((uintptr_t)PDPTEPtr >> 12);
+    }
+    else
+        PDPTEPtr = (PageDirectoryPointerTableEntryPtr *)((uintptr_t)PML4.GetAddress() << 12);
+    PML4.raw |= DirectoryFlags;
+    BPTable->Entries[Index.PMLIndex] = PML4;
+
+    PageDirectoryPointerTableEntry PDPTE = PDPTEPtr->Entries[Index.PDPTEIndex];
+    PageDirectoryEntryPtr *PDEPtr = nullptr;
+    if (!PDPTE.Present)
+    {
+        PDEPtr = (PageDirectoryEntryPtr *)RequestPage();
+        {
+            void *ptr = PDEPtr;
+            int value = 0;
+            size_t num = 0x1000;
+            uint8_t *p = (uint8_t *)ptr;
+            for (size_t i = 0; i < num; i++)
+                p[i] = value;
+        }
+        PDPTE.Present = true;
+        PDPTE.SetAddress((uintptr_t)PDEPtr >> 12);
+    }
+    else
+        PDEPtr = (PageDirectoryEntryPtr *)((uintptr_t)PDPTE.GetAddress() << 12);
+    PDPTE.raw |= DirectoryFlags;
+    PDPTEPtr->Entries[Index.PDPTEIndex] = PDPTE;
+
+    PageDirectoryEntry PDE = PDEPtr->Entries[Index.PDEIndex];
+    PageTableEntryPtr *PTEPtr = nullptr;
+    if (!PDE.Present)
+    {
+        PTEPtr = (PageTableEntryPtr *)RequestPage();
+        {
+            void *ptr = PTEPtr;
+            int value = 0;
+            size_t num = 0x1000;
+            uint8_t *p = (uint8_t *)ptr;
+            for (size_t i = 0; i < num; i++)
+                p[i] = value;
+        }
+        PDE.Present = true;
+        PDE.SetAddress((uintptr_t)PTEPtr >> 12);
+    }
+    else
+        PTEPtr = (PageTableEntryPtr *)((uintptr_t)PDE.GetAddress() << 12);
+    PDE.raw |= DirectoryFlags;
+    PDEPtr->Entries[Index.PDEIndex] = PDE;
+
+    PageTableEntry PTE = PTEPtr->Entries[Index.PTEIndex];
+    PTE.Present = true;
+    PTE.raw |= Flags;
+    PTE.SetAddress((uintptr_t)PhysicalAddress >> 12);
+    PTEPtr->Entries[Index.PTEIndex] = PTE;
+    asmv("invlpg (%0)"
+         :
+         : "r"(VirtualAddress)
+         : "memory");
+}
+
+EXTERNC __attribute__((section(".bootstrap.text"))) SafeFunction NIF __attribute__((section(".bootstrap.text"))) void UpdatePageTable64()
+{
+    BPTable = (PageTable4 *)BootPageTable;
+
+    // for (size_t i = 0; i < 0x10000000; i += 0x1000)
+    //     Map((void *)i, (void *)i, 0x3);
+
+    uintptr_t KernelStart = (uintptr_t)&_kernel_start;
+    uintptr_t KernelEnd = (uintptr_t)&_kernel_end;
+    uintptr_t PhysicalStart = KernelStart - 0xFFFFFFFF80000000;
+    for (uintptr_t i = KernelStart; i < KernelEnd; i += 0x1000)
+    {
+        Map((void *)i, (void *)PhysicalStart, 0x3);
+        PhysicalStart += 0x1000;
+    }
+
+    asmv("mov %%cr3, %%rax\n"
+         "mov %%rax, %%cr3\n"
+         :
+         :
+         : "rax");
+}
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp b/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
index f85ac3b0..f7748b97 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
@@ -6,8 +6,6 @@
 
 #include "../../../../kernel.h"
 
-BootInfo mb2binfo;
-
 enum VideoType
 {
     VIDEO_TYPE_NONE = 0x00,
@@ -50,9 +48,37 @@ void GetSMBIOS()
     }
 }
 
-void ProcessMB2(unsigned long Info)
+extern "C" unsigned int MB2_HeaderMagic;
+extern "C" unsigned long MB2_HeaderInfo;
+
+EXTERNC void Multiboot2Entry()
 {
-    uint8_t *VideoBuffer = (uint8_t *)0xB8F00 + 0xC0000000;
+    unsigned long Info = MB2_HeaderInfo;
+    unsigned int Magic = MB2_HeaderMagic;
+    if (Info == NULL || Magic == NULL)
+    {
+        if (Magic == NULL)
+            error("Multiboot magic is NULL");
+        if (Info == NULL)
+            error("Multiboot info is NULL");
+        CPU::Stop();
+    }
+    else if (Magic != MULTIBOOT2_BOOTLOADER_MAGIC)
+    {
+        error("Multiboot magic is invalid (%#x != %#x)", Magic, MULTIBOOT2_BOOTLOADER_MAGIC);
+        CPU::Stop();
+    }
+
+    uint64_t div = 1193180 / 1000;
+    outb(0x43, 0xB6);
+    outb(0x42, (uint8_t)div);
+    outb(0x42, (uint8_t)(div >> 8));
+    uint8_t tmp = inb(0x61);
+    if (tmp != (tmp | 3))
+        outb(0x61, tmp | 3);
+
+    BootInfo mb2binfo;
+    uint8_t *VideoBuffer = (uint8_t *)0xB8F00;
     int pos = 0;
     auto InfoAddress = Info;
     for (auto Tag = (struct multiboot_tag *)((uint8_t *)InfoAddress + 8);
@@ -90,7 +116,7 @@ void ProcessMB2(unsigned long Info)
         {
             multiboot_tag_module *module = (multiboot_tag_module *)Tag;
             static int module_count = 0;
-            mb2binfo.Modules[module_count++].Address = (void *)module->mod_start;
+            mb2binfo.Modules[module_count++].Address = (void *)(uint64_t)module->mod_start;
             mb2binfo.Modules[module_count++].Size = module->size;
             strncpy(mb2binfo.Modules[module_count++].Path, "(null)", 6);
             strncpy(mb2binfo.Modules[module_count++].CommandLine, module->cmdline,
@@ -187,11 +213,12 @@ void ProcessMB2(unsigned long Info)
             {
             case MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED:
             {
-                fixme("indexed");
+                mb2binfo.Framebuffer[fb_count].Type = Indexed;
                 break;
             }
             case MULTIBOOT_FRAMEBUFFER_TYPE_RGB:
             {
+                mb2binfo.Framebuffer[fb_count].Type = RGB;
                 mb2binfo.Framebuffer[fb_count].RedMaskSize = fb->framebuffer_red_mask_size;
                 mb2binfo.Framebuffer[fb_count].RedMaskShift = fb->framebuffer_red_field_position;
                 mb2binfo.Framebuffer[fb_count].GreenMaskSize = fb->framebuffer_green_mask_size;
@@ -202,11 +229,11 @@ void ProcessMB2(unsigned long Info)
             }
             case MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT:
             {
-                fixme("ega_text");
+                mb2binfo.Framebuffer[fb_count].Type = EGA;
                 break;
             }
             }
-            debug("Framebuffer %d: %dx%d %d bpp", Tag, fb->common.framebuffer_width, fb->common.framebuffer_height, fb->common.framebuffer_bpp);
+            debug("Framebuffer %d: %dx%d %d bpp", fb_count, fb->common.framebuffer_width, fb->common.framebuffer_height, fb->common.framebuffer_bpp);
             debug("More info:\nAddress: %p\nPitch: %lld\nMemoryModel: %d\nRedMaskSize: %d\nRedMaskShift: %d\nGreenMaskSize: %d\nGreenMaskShift: %d\nBlueMaskSize: %d\nBlueMaskShift: %d",
                   fb->common.framebuffer_addr, fb->common.framebuffer_pitch, fb->common.framebuffer_type,
                   fb->framebuffer_red_mask_size, fb->framebuffer_red_field_position, fb->framebuffer_green_mask_size,
@@ -291,8 +318,8 @@ void ProcessMB2(unsigned long Info)
         case MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDR:
         {
             multiboot_tag_load_base_addr *load_base_addr = (multiboot_tag_load_base_addr *)Tag;
-            mb2binfo.Kernel.PhysicalBase = (void *)load_base_addr->load_base_addr;
-            mb2binfo.Kernel.VirtualBase = (void *)(load_base_addr->load_base_addr + 0xC0000000);
+            mb2binfo.Kernel.PhysicalBase = (void *)(uint64_t)load_base_addr->load_base_addr;
+            mb2binfo.Kernel.VirtualBase = (void *)(uint64_t)(load_base_addr->load_base_addr + 0xFFFFFFFF80000000);
             debug("Kernel base: %p (physical) %p (virtual)", mb2binfo.Kernel.PhysicalBase, mb2binfo.Kernel.VirtualBase);
             break;
         }
@@ -303,37 +330,9 @@ void ProcessMB2(unsigned long Info)
         }
         }
     }
-}
-
-EXTERNC void Multiboot2Entry(unsigned long Info, unsigned int Magic)
-{
-    if (Info == NULL || Magic == NULL)
-    {
-        if (Magic == NULL)
-            error("Multiboot magic is NULL");
-        if (Info == NULL)
-            error("Multiboot info is NULL");
-        CPU::Stop();
-    }
-    else if (Magic != MULTIBOOT2_BOOTLOADER_MAGIC)
-    {
-        error("Multiboot magic is invalid (%#x != %#x)", Magic, MULTIBOOT2_BOOTLOADER_MAGIC);
-        CPU::Stop();
-    }
-
-    uint64_t div = 1193180 / 1000;
-    outb(0x43, 0xB6);
-    outb(0x42, (uint8_t)div);
-    outb(0x42, (uint8_t)(div >> 8));
-    uint8_t tmp = inb(0x61);
-    if (tmp != (tmp | 3))
-        outb(0x61, tmp | 3);
-
-    ProcessMB2(Info);
 
     tmp = inb(0x61) & 0xFC;
     outb(0x61, tmp);
 
-    CPU::Stop();
     Entry(&mb2binfo);
 }
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm b/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm
index f6525d54..eba5546c 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm
+++ b/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm
@@ -10,76 +10,36 @@ BootPageTable:
 section .bootstrap.text
 global UpdatePageTable
 UpdatePageTable:
-	mov edi, (BootPageTable + 0x0000)
+	mov edi, (BootPageTable + 0x0000) ; First PML4E
+	mov eax, (BootPageTable + 0x1000) ; First PDPTE
+	or eax, 11b ; Bitwise OR on rax (PDPTE) with 11b (Present, Write)
+	mov dword [edi], eax ; Write 11b to PML4E
 
-	mov eax, (BootPageTable + 0x1000)
-	or eax, 0x3
-	mov dword [edi], eax
-
-	mov ecx, PAGE_TABLE_SIZE
-	mov edi, (BootPageTable + 0x1000)
-	mov eax, (BootPageTable + 0x2000)
-	or eax, 0x3
-	mov ebx, 0x0
+	mov edi, (BootPageTable + 0x1000) ; First PDPTE
+	mov eax, (BootPageTable + 0x2000) ; First PDE
+	or eax, 11b ; Bitwise OR on rax (PDE) with 11b (Present, Write)
 
+	mov ecx, PAGE_TABLE_SIZE ; For loop instruction
+	mov ebx, 0x0 ; Value to store in the next 4 bytes
 	.FillPageTableLevel3:
-		mov dword [edi], eax
-		mov dword [edi + 4], ebx
-		add eax, 1 << 12
-		adc ebx, 0
-		add edi, 8
-		loop .FillPageTableLevel3
+		mov dword [edi], eax ; Store modified PDE in PDPTE
+		mov dword [edi + 4], ebx ; Store the rbx value in the next 4 bytes
+		add eax, 0x1000 ; Increment (page size)
+		adc ebx, 0 ; Add 0 to carry flag
+		add edi, 8 ; Add 8 to rdi (next PDE)
+		loop .FillPageTableLevel3 ; Loop until rcx is 0
 
-	mov ecx, (512 * PAGE_TABLE_SIZE)
-	mov edi, (BootPageTable + 0x2000)
-	mov eax, 0x0 | 0x3 | 1 << 7
-	mov ebx, 0x0
+	mov edi, (BootPageTable + 0x2000) ; First PDE
+	mov eax, 11b | 10000000b ; Present, Write, Large Page
 
+	mov ecx, (512 * PAGE_TABLE_SIZE) ; For loop instruction
+	mov ebx, 0x0 ; Value to store in the next 4 bytes
 	.FillPageTableLevel2:
-		mov dword [edi], eax
-		mov dword [edi + 4], ebx
-		add eax, 1 << 21
-		adc ebx, 0
-		add edi, 8
-		loop .FillPageTableLevel2
-
-	ret
-
-[bits 64]
-section .bootstrap.text
-global UpdatePageTable64
-UpdatePageTable64:
-	mov rdi, (BootPageTable + 0x0000)
-
-	mov rax, (BootPageTable + 0x1000)
-	or rax, 0x3
-	mov [rdi], rax
-
-	mov rcx, PAGE_TABLE_SIZE
-	mov rdi, (BootPageTable + 0x1000)
-	mov rax, (BootPageTable + 0x2000)
-	or rax, 0x3
-	mov rbx, 0x0
-
-	.FillPageTableLevel3:
-		mov [rdi], rax
-		mov [rdi + 4], rbx
-		add rax, 1 << 12
-		adc rbx, 0
-		add rdi, 8
-		loop .FillPageTableLevel3
-
-	mov rcx, (512 * PAGE_TABLE_SIZE)
-	mov rdi, (BootPageTable + 0x2000)
-	mov rax, 0x0 | 0x3 | 1 << 7
-	mov rbx, 0x0
-
-	.FillPageTableLevel2:
-		mov [rdi], rax
-		mov [rdi + 4], rbx
-		add rax, 1 << 21
-		adc rbx, 0
-		add rdi, 8
-		loop .FillPageTableLevel2
+		mov dword [edi], eax ; Store modified PDE in PDPTE
+		mov dword [edi + 4], ebx ; Store the rbx value in the next 4 bytes
+		add eax, 1 << 21 ; Increment (page size)
+		adc ebx, 0 ; Add 0 (carry flag) to rbx to increment if there was a carry
+		add edi, 8 ; Add 8 to rdi (next PDE)
+		loop .FillPageTableLevel2 ; Loop until rcx is 0
 
 	ret
diff --git a/Core/Memory/Memory.cpp b/Core/Memory/Memory.cpp
index 968072ea..1dca2f74 100644
--- a/Core/Memory/Memory.cpp
+++ b/Core/Memory/Memory.cpp
@@ -71,8 +71,8 @@ NIF void MapFromZero(PageTable4 *PT, BootInfo *Info)
         for (size_t t = 0; t < MemSize; t += PAGE_SIZE)
         {
             va.Map((void *)t, (void *)t, PTFlag::RW /* | PTFlag::US */);
-            va.Map((void *)VirtualOffsetNormalVMA, (void *)t, PTFlag::RW /* | PTFlag::US */);
-            VirtualOffsetNormalVMA += PAGE_SIZE;
+            // va.Map((void *)VirtualOffsetNormalVMA, (void *)t, PTFlag::RW /* | PTFlag::US */);
+            // VirtualOffsetNormalVMA += PAGE_SIZE;
         }
     }
     else
diff --git a/include/boot/binfo.h b/include/boot/binfo.h
index 944b7f03..01947c7e 100644
--- a/include/boot/binfo.h
+++ b/include/boot/binfo.h
@@ -3,7 +3,7 @@
 
 enum MemoryType
 {
-    Unknown,
+    Unknown_Memory_Type,
     Usable,
     Reserved,
     ACPIReclaimable,
@@ -11,7 +11,16 @@ enum MemoryType
     BadMemory,
     BootloaderReclaimable,
     KernelAndModules,
-    Framebuffer
+    Framebuffer,
+    Unknown
+};
+
+enum FramebufferType
+{
+    Unknown_Framebuffer_Type,
+    Indexed,
+    RGB,
+    EGA
 };
 
 #define MAX_FRAMEBUFFERS 16
@@ -22,6 +31,7 @@ struct BootInfo
 {
     struct FramebufferInfo
     {
+        enum FramebufferType Type;
         void *BaseAddress;
         __UINT64_TYPE__ Width;
         __UINT64_TYPE__ Height;

From fea5485958f6a4dae7d5c29db24a4a4292c96610 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Wed, 19 Apr 2023 04:17:11 +0300
Subject: [PATCH 6/7] todo MB2MemoryMapper.cpp

---
 .../amd64/Bootstrap/Multiboot2/Detection.asm   |  4 ++--
 .../amd64/Bootstrap/Multiboot2/Entry.asm       | 10 +++++-----
 .../amd64/Bootstrap/Multiboot2/Header.asm      | 18 ++++++++++++++++++
 .../Bootstrap/Multiboot2/MB2MemoryMapper.cpp   |  4 ++++
 .../amd64/Bootstrap/Multiboot2/PageTable.asm   |  4 ++--
 Architecture/amd64/linker.ld                   |  2 +-
 Core/Memory/PhysicalMemoryManager.cpp          |  6 +++++-
 7 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/Architecture/amd64/Bootstrap/Multiboot2/Detection.asm b/Architecture/amd64/Bootstrap/Multiboot2/Detection.asm
index ee6166a7..f0ba7021 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/Detection.asm
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Detection.asm
@@ -16,7 +16,7 @@ DetectCPUID:
     jz .NoCPUID
     ret
 .NoCPUID:
-    mov word [0xb8F00], 0xF00F ; .
+    ; mov word [0xb8F00], 0xF00F ; .
 .Loop:
     cli
     hlt
@@ -34,7 +34,7 @@ Detect64Bit:
     jz .NoLongMode
     ret
 .NoLongMode:
-    mov word [0xb8F00], 0xF00A ; .
+    ; mov word [0xb8F00], 0xF00A ; .
 .Loop:
     cli
     hlt
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm b/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
index 6c7c0d95..7a169234 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Entry.asm
@@ -29,7 +29,7 @@ MB2_HeaderInfo:
 section .bootstrap.text
 MB2_start:
 	cli
-	mov word [0xb8F00], 0x072E ; .
+	; mov word [0xb8F00], 0x072E ; .
     mov [MB2_HeaderMagic], eax
     mov [MB2_HeaderInfo], ebx
 
@@ -37,7 +37,7 @@ MB2_start:
 	call DetectCPUID
 	call Detect64Bit
 
-	mov word [0xb8F02], 0x072E ; .
+	; mov word [0xb8F02], 0x072E ; .
 
 	mov ecx, cr0
 	and ecx, 0x7fffffff ; Clear PG
@@ -56,7 +56,7 @@ MB2_start:
 	mov edi, BootPageTable
 	mov cr3, edi
 
-	mov word [0xb8F04], 0x072E ; .
+	; mov word [0xb8F04], 0x072E ; .
 
 	; Enable long mode
 	mov ecx, 0xC0000080 ; EFER
@@ -84,7 +84,7 @@ MB2_start:
 [bits 64]
 HigherHalfStart:
 	cli
-	mov word [0xb8F06], 0x072E ; .
+	; mov word [0xb8F06], 0x072E ; .
 	call UpdatePageTable64
 
 	; Load the new page table
@@ -98,7 +98,7 @@ HigherHalfStart:
 	mov gs, ax
 	mov ss, ax
 
-	mov word [0xb8F08], 0x072E ; .
+	; mov word [0xb8F08], 0x072E ; .
 	mov rsp, (KernelStack + KERNEL_STACK_SIZE)
 	mov rbp, (KernelStack + KERNEL_STACK_SIZE)
 
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/Header.asm b/Architecture/amd64/Bootstrap/Multiboot2/Header.asm
index b05828df..844b61d7 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/Header.asm
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Header.asm
@@ -1,3 +1,5 @@
+extern MB2_start
+
 [bits 32]
 section .multiboot2
 align 4096
@@ -34,6 +36,22 @@ MB2_INFO_REQUEST_TAG_START:
     dd 21 ; Load Base Address
 MB2_INFO_REQUEST_TAG_END:
 align 8
+MB2_ENTRY_TAG:        
+    dw 3
+    dw 0
+    dd MB2_ENTRY_TAG_END - MB2_ENTRY_TAG
+    dd MB2_start
+MB2_ENTRY_TAG_END:
+align 8
+MB2_FRAMEBUFFER_TAG_START:
+    dw 5
+    dw 1
+    dd MB2_FRAMEBUFFER_TAG_END - MB2_FRAMEBUFFER_TAG_START
+    dd 1280 ; Width
+    dd 720 ; Height
+    dd 32 ; Depth
+MB2_FRAMEBUFFER_TAG_END:
+align 8
 MB2_TAG_START:
     dw 0
     dw 0
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/MB2MemoryMapper.cpp b/Architecture/amd64/Bootstrap/Multiboot2/MB2MemoryMapper.cpp
index a128b496..fb3b16b0 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/MB2MemoryMapper.cpp
+++ b/Architecture/amd64/Bootstrap/Multiboot2/MB2MemoryMapper.cpp
@@ -259,6 +259,10 @@ __always_inline inline SafeFunction NIF void Map(void *VirtualAddress, void *Phy
 
 EXTERNC __attribute__((section(".bootstrap.text"))) SafeFunction NIF __attribute__((section(".bootstrap.text"))) void UpdatePageTable64()
 {
+    /*
+    TODO: this code corrupts the page table
+    */
+
     BPTable = (PageTable4 *)BootPageTable;
 
     // for (size_t i = 0; i < 0x10000000; i += 0x1000)
diff --git a/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm b/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm
index eba5546c..11982e26 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm
+++ b/Architecture/amd64/Bootstrap/Multiboot2/PageTable.asm
@@ -1,7 +1,7 @@
-PAGE_TABLE_SIZE equ 0x4 ; 1GB
+PAGE_TABLE_SIZE equ 0x8 ; 2GB
 [bits 32]
 
-section .bootstrap.data
+section .bootstrap.bss
 align 0x1000
 global BootPageTable
 BootPageTable:
diff --git a/Architecture/amd64/linker.ld b/Architecture/amd64/linker.ld
index 96e0e549..9a938bae 100644
--- a/Architecture/amd64/linker.ld
+++ b/Architecture/amd64/linker.ld
@@ -4,7 +4,7 @@ OUTPUT_ARCH(i386:x86-64)
 KERNEL_LMA = 16M;
 KERNEL_VMA = 0xFFFFFFFF80000000;
 
-ENTRY(MB2_start)
+ENTRY(_start)
 
 SECTIONS
 {
diff --git a/Core/Memory/PhysicalMemoryManager.cpp b/Core/Memory/PhysicalMemoryManager.cpp
index 0da3ab13..21424d73 100644
--- a/Core/Memory/PhysicalMemoryManager.cpp
+++ b/Core/Memory/PhysicalMemoryManager.cpp
@@ -7,6 +7,8 @@
 
 #include "../../kernel.h"
 
+extern "C" char BootPageTable[]; // 0x10000 in length
+
 namespace Memory
 {
     uint64_t Physical::GetTotalMemory()
@@ -371,8 +373,10 @@ namespace Memory
         for (uint64_t i = 0; i < Info->Memory.Entries; i++)
             if (Info->Memory.Entry[i].Type != Usable)
                 this->ReservePages((void *)Info->Memory.Entry[i].BaseAddress, Info->Memory.Entry[i].Length / PAGE_SIZE + 1);
-        trace("Locking bitmap pages...");
+
         this->ReservePages(0, 0x100);
+        this->ReservePages(BootPageTable, TO_PAGES(0x10000));
+        trace("Locking bitmap pages...");
         this->LockPages(PageBitmap.Buffer, PageBitmap.Size / PAGE_SIZE + 1);
     }
 

From 1a3bdbb843500339a4e2a23addaf46ed5b5c9d2d Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Sat, 29 Apr 2023 07:02:57 +0300
Subject: [PATCH 7/7] Display &elf->sections too

---
 Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp b/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
index f7748b97..08f4cf64 100644
--- a/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
+++ b/Architecture/amd64/Bootstrap/Multiboot2/Multiboot2.cpp
@@ -244,8 +244,8 @@ EXTERNC void Multiboot2Entry()
         case MULTIBOOT_TAG_TYPE_ELF_SECTIONS:
         {
             multiboot_tag_elf_sections *elf = (multiboot_tag_elf_sections *)Tag;
-            fixme("elf_sections->[num=%d, size=%d, entsize=%d, shndx=%d]",
-                  elf->num, elf->size, elf->entsize, elf->shndx);
+            fixme("elf_sections->[sections=%#lx num=%d, size=%d, entsize=%d, shndx=%d]",
+                  &elf->sections, elf->num, elf->size, elf->entsize, elf->shndx);
             break;
         }
         case MULTIBOOT_TAG_TYPE_APM: