Switched to grub

This really isn't what I wanted because grub is very big and bloaty but
my own bootloader was very poorly written and I really want to implement
a filesystem like ext2 which wouldn't work with my own bootloader.
Furthermore this commit fixes many small issues including the one
occurring due to the statically linked user binary (I just removed
the linking for now).

19 files changed, 310 insertions, 1006 deletions

diff --git a/run b/run
index 8c2a8c9..91f1f73 100755
--- a/run
+++ b/run
@@ -111,43 +111,42 @@ make_build() {
 		compile_with_flags -O2 -c ./"${line}" -I ./src/userspace -o ./build/userspace/"${stripped}"
 	done <./build/tmp
 	rm ./build/tmp
-	compile_with_flags -emain -O2 ./build/userspace/*.o -T ./src/userspace/linker.ld -I ./src/userspace -o ./build/user.bin
+	compile_with_flags -emain -O2 ./build/userspace/*.o -I ./src/userspace -o ./build/user.bin
 
 	# Create ISO
-	mkdir -p ./iso/boot/
-	mv ./build/melvix.bin ./iso/boot/kernel.bin
-	nasm ./src/bootloader/cd.asm -f bin -o ./iso/boot/cd.bin || exit 1
-	nasm ./src/bootloader/hdd1.asm -f bin -o ./iso/boot/hdd1.bin || exit 1
-	nasm ./src/bootloader/hdd2.asm -f bin -o ./iso/boot/hdd2.bin || exit 1
-	cp ./build/user.bin ./iso/user.bin || exit 1
-	cp ./build/font.bin ./iso/font.bin || exit 1
-	genisoimage -quiet -input-charset utf-8 -no-emul-boot -b boot/cd.bin -o ./build/melvix.iso ./iso
+	mkdir -p ./iso/boot/grub/
+	cp ./build/melvix.bin ./iso/boot/kernel.bin
+	cp ./src/bootloader/grub.cfg ./iso/boot/grub/
+	cp ./build/user.bin ./iso/user.bin
+	cp ./build/font.bin ./iso/font.bin
+	grub-mkrescue -o ./build/melvix.iso ./iso/
 	head -c 10485760 /dev/zero >./build/hdd10M.img
 
 	printf "Build finshed successfully!\n\n"
 }
 
 make_test() {
-	qemu_with_flags -cdrom ./build/melvix.iso -drive file=./build/hdd10M.img,format=raw
+	qemu_with_flags -cdrom ./build/melvix.iso #-drive file=./build/hdd10M.img,format=raw
 }
 
 make_debug() {
-	qemu_with_flags -s -cdrom ./build/melvix.iso -drive file=./build/hdd10M.img,format=raw
+	qemu_with_flags -s -cdrom ./build/melvix.iso #-drive file=./build/hdd10M.img,format=raw
 }
 
 make_image_debug() {
-	qemu_with_flags -cdrom ./build/melvix.iso -drive file=./build/hdd10M.img,format=raw
-	qemu_with_flags -drive file=./build/hdd10M.img,format=raw
+	qemu_with_flags -cdrom ./build/melvix.iso #-drive file=./build/hdd10M.img,format=raw
+	#qemu_with_flags -drive file=./build/hdd10M.img,format=raw
 }
 
 make_image() {
-	start=$(date +%s.%N)
-	qemu_with_flags -nographic -cdrom ./build/melvix.iso -drive file=./build/hdd10M.img,format=raw >install.log
-	end=$(date +%s.%N)
-	cat install.log
-	printf "[LOG END]\n\n"
-	tail install.log | grep -q "Installation successful!" && echo Booted and installed within "$(echo "$end - $start" | bc -l)" seconds || echo Installation failed! && exit 1
-	rm install.log
+	#start=$(date +%s.%N)
+	#qemu_with_flags -nographic -cdrom ./build/melvix.iso -drive file=./build/hdd10M.img,format=raw >install.log
+	#end=$(date +%s.%N)
+	#cat install.log
+	#printf "[LOG END]\n\n"
+	#tail install.log | grep -q "Installation successful!" && echo Booted and installed within "$(echo "$end - $start" | bc -l)" seconds || echo Installation failed! && exit 1
+	#rm install.log
+	echo "This test is currently disabled"
 }
 
 make_sync() {
diff --git a/src/bootloader/cd.asm b/src/bootloader/cd.asm
deleted file mode 100644
index 1661df1..0000000
--- a/src/bootloader/cd.asm
+++ /dev/null
@@ -1,443 +0,0 @@
-BITS 16
-ORG 0x7C00
-
-; Save the boot drive id
-mov [bootDriveID], dl
-
-jmp start
-
-print:
-    mov ah, 0x0E
-    xor bh, bh
-    .print_L:
-        lodsb
-        test al, al
-        jz .print_end
-        int 0x10
-        jmp .print_L
-    .print_end:
-    ret
-
-bootDriveID: db 0
-
-dapack:
-    dapack_size: db 0x10
-    dapack_null: db 0x00
-    dapack_blkcount: dw 0x0001
-    dapack_boffset: dw 0x9000
-    dapack_bsegment: dw 0x0000
-    dapack_start: dd 0x00000000
-    dapack_upper_lba_bits: dd 0x00000000
-
-readsector:
-    mov dword [dapack_start], eax
-    mov ah, 0x42
-    mov dl, [bootDriveID]
-    xor bx, bx
-    mov ds, bx
-    mov si, dapack
-    int 0x13
-    ret
-
-filenameLength dw 1
-filename dw 1
-
-findfile:
-    mov bx, [esp+2]
-    mov ax, [esp+4]
-    mov [filenameLength], ax
-    mov ax, [esp+6]
-    mov [filename], ax
-
-    .findfile_L:
-        mov al, [bx]
-
-        test al, al
-        jz .findfile_notfound
-
-        mov ah, [bx+32]
-        cmp ah, byte [filenameLength]
-        jnz .findfile_keep
-
-        call findfile_check
-        test ax, ax
-        jz findfile_found
-
-        .findfile_keep:
-        mov al, [bx]
-        xor ah, ah
-        add bx, ax
-        jmp .findfile_L
-
-    .findfile_notfound:
-        xor ax, ax
-        inc ax
-        ret
-
-    findfile_check:
-        pusha
-        add bx, 33
-        mov ax, bx
-
-        xor cx, cx
-        .findfile_check_L:
-            mov bx, [filename]
-            add bx, cx
-            mov dh, [bx]
-            mov bx, ax
-            add bx, cx
-            mov dl, [bx]
-            cmp dh, dl
-            jnz .findfile_check_fail
-
-            inc cx
-            cmp cx, word [filenameLength]
-            jz .findfile_check_success
-            jmp .findfile_check_L
-
-            .findfile_check_fail:
-                popa
-                xor ax, ax
-                inc ax
-                ret
-            .findfile_check_success:
-                popa
-                xor ax, ax
-                ret
-
-    findfile_found:
-        xor ax, ax
-        ret
-
-LOAD_PVD:
-    mov eax, 0x10
-    PVD_L:
-        call readsector
-        mov bx, [dapack_boffset]
-        mov bl, [bx]
-        cmp bl, 0x01
-        jz PVD_FOUND
-        inc eax
-        jmp PVD_L
-    PVD_FOUND:
-    ret
-
-checkA20:
-    ; Stolen from https://wiki.osdev.org/A20_Line
-    pushf
-    push ds
-    push es
-    push di
-    push si
-    cli
-    xor ax, ax
-    mov es, ax
-    not ax
-    mov ds, ax
-    mov di, 0x0500
-    mov si, 0x0510
-    mov al, byte [es:di]
-    push ax
-    mov al, byte [ds:si]
-    push ax
-    mov byte [es:di], 0x00
-    mov byte [ds:si], 0xFF
-    cmp byte [es:di], 0xFF
-    pop ax
-    mov byte [ds:si], al
-    pop ax
-    mov byte [es:di], al
-    mov ax, 0
-    jz checkA20_exit
-    mov ax, 1
-    checkA20_exit:
-        pop si
-        pop di
-        pop es
-        pop ds
-        popf
-        ret
-
-welcome db "Melvix", 0x0A, 0x0D, 0x00
-nolba db "BIOS lacks support for lba addressing.", 0x00
-noboot db "Boot directory could not be found.", 0x00
-noa20 db "A20 could not be enabled.", 0
-loading db "Loading kernel...", 0x0A, 0x0D, 0x00
-nokernel db "kernel.bin could not be found!", 0
-booting db "Booting...", 0x0A, 0x0D, 0x00
-nomem db "BIOS does not support memory detection!", 0
-memno20 db "BIOS returns memory detection with 24 bytes. This has never been seen!", 0
-
-start:
-    ; Check if lba is supported by the BIOS.
-    mov ah, 0x41
-    mov bx, 0x55AA
-    int 0x13
-    jc lba_not_supported
-    cmp bx, 0xAA55
-    jnz lba_not_supported
-
-    call checkA20
-    test ax, ax
-    jnz A20_ENABLED
-
-    in al, 0x92
-    or al, 2
-    out 0x92, al
-
-    call checkA20
-    test ax, ax
-    jnz A20_ENABLED
-
-    mov si, noa20
-    call print
-    jmp $
-
-A20_ENABLED:
-    ; Inspired by https://wiki.osdev.org/Unreal_Mode
-    cli
-    push ds
-    lgdt [gdtinfo]
-
-    mov eax, cr0
-    or al, 1
-    mov cr0, eax
-
-    jmp $+2
-
-    mov bx, 0x08
-    mov ds, bx
-
-    and al, 0xFE
-    mov cr0, eax
-    pop ds
-
-    mov si, loading
-    call print
-
-    call LOAD_PVD
-
-    mov bx, 0x9000
-    add bx, 156
-    add bx, 2
-    mov eax, dword [bx]
-    call readsector
-
-    push boot
-    push boot_len
-    push 0x9000
-    call findfile
-    add esp, 6
-    test ax, ax
-    jz continue_BOOT
-
-    mov si, noboot
-    call print
-    jmp $
-
-continue_BOOT:
-    mov word [dapack_blkcount], 0x0001
-    add bx, 2
-    mov eax, [bx]
-    call readsector
-
-    push kernelbin
-    push kernelbin_len
-    push 0x9000
-    call findfile
-    add esp, 6
-    test ax, ax
-    jz continue_KERNEL
-
-    mov si, nokernel
-    call print
-    jmp $
-
-continue_KERNEL:
-    mov word [dapack_blkcount], 1
-    mov word [dapack_boffset], 0x9000
-
-    push bx
-    add bx, 10
-    mov eax, [bx]
-    xor edx, edx
-    mov ebx, 2048
-    div ebx
-    inc eax
-    pop bx
-    push eax
-
-    add bx, 2
-    mov eax, [bx]
-    push eax
-
-    ; Offsetless count.
-    xor ecx, ecx
-LOAD_KERNEL:
-    mov eax, [esp]
-    add eax, ecx
-    call readsector
-
-    mov eax, ecx
-    shl eax, 11
-    add eax, 0x200000
-
-    push ecx
-    xor ecx, ecx
-    .LOAD_KERNEL_L:
-        mov ebx, ecx
-        add ebx, 0x9000
-        mov ebx, dword [ebx]
-
-        mov edx, ebx
-        mov ebx, eax
-        add ebx, ecx
-        mov dword [ebx], edx
-
-        add ecx, 4
-        cmp ecx, 2048
-        jl .LOAD_KERNEL_L
-    pop ecx
-
-    inc ecx
-    cmp ecx, dword [esp+4]
-    jl LOAD_KERNEL
-
-mov si, booting
-call print
-
-mov dl, [bootDriveID]
-mov byte [0x9000], dl
-
-mov di, 0xA000
-mov eax, 0xE820
-xor ebx, ebx
-mov ecx, 24
-mov edx, 0x534D4150
-int 0x15
-
-jc BIOS_NO_MEM
-cmp eax, 0x534D4150
-jnz BIOS_NO_MEM
-cmp cl, 20
-jnz BIOS_MEM_NO20
-
-MEM_L:
-    test ebx, ebx
-    jz MEM_FINISHED
-
-    mov ax, di
-    xor ch, ch
-    add ax, cx
-    mov di, ax
-
-    mov eax, 0xE820
-    mov ecx, 24
-    int 0x15
-    jmp MEM_L
-
-MEM_FINISHED:
-    mov eax, cr0
-    or al, 1
-    mov cr0, eax
-
-    mov ax, 0x08
-    mov ds, ax
-    mov es, ax
-    mov fs, ax
-    mov gs, ax
-    mov ss, ax
-
-; Infomation: https://wiki.osdev.org/ELF
-mov ebx, 0x20002C
-mov dl, byte [ebx]
-push dx
-
-mov ebx, 0x20001C
-mov ebx, dword [ebx]
-push ebx
-
-xor dh, dh
-PHT:
-    xor eax, eax
-    mov al, dh
-    shl eax, 5
-    add eax, dword [esp]
-    add eax, 0x200000
-    mov ebx, eax
-
-    mov eax, dword [ebx]
-    cmp eax, 1
-    jnz .PHT_ignore
-
-    add ebx, 4
-    mov eax, dword [ebx]
-    add eax, 0x200000
-    push eax
-
-    add ebx, 4
-    mov eax, dword [ebx]
-    push eax
-
-    add ebx, 8
-    mov eax, dword [ebx]
-    push eax
-
-    push dx
-    xor ecx, ecx
-    .MOVE_KERNEL_L:
-        mov ebx, [esp+10]
-        add ebx, ecx
-        mov ebx, dword [ebx]
-
-        mov eax, ebx
-        mov ebx, dword [esp+6]
-        add ebx, ecx
-        mov dword [ebx], eax
-
-        add ecx, 4
-        cmp ecx, dword [esp+2]
-        jl .MOVE_KERNEL_L
-    pop dx
-    add esp, 12
-
-    .PHT_ignore:
-        inc dh
-        cmp dh, dl
-        jl PHT
-
-jmp (codedesc - gdt):protectedMode
-
-protectedMode:
-    BITS 32
-    mov ebx, 0x100000
-    mov eax, dword [ebx]
-    jmp eax
-
-BITS 16
-BIOS_NO_MEM:
-    mov si, nomem
-    call print
-    jmp $
-BIOS_MEM_NO20:
-    mov si, memno20
-    call print
-    jmp $
-
-gdtinfo:
-    dw gdt_end - gdt - 1
-    dd gdt
-    gdt dd 0, 0
-    flatdesc db 0xff, 0xff, 0, 0, 0, 10010010b, 11001111b, 0
-    codedesc db 0xff, 0xff, 0, 0, 0, 10011010b, 11001111b, 0
-    gdt_end:
-
-lba_not_supported:
-    mov si, nolba
-    call print
-    jmp $
-
-boot db "BOOT"
-boot_len equ ($ - boot)
-kernelbin db "KERNEL.BIN", 0x3B, "1"
-kernelbin_len equ ($ - kernelbin)
\ No newline at end of file
diff --git a/src/bootloader/grub.cfg b/src/bootloader/grub.cfg
new file mode 100644
index 0000000..227030e
--- /dev/null
+++ b/src/bootloader/grub.cfg
@@ -0,0 +1,6 @@
+set timeout=0
+set default=0
+menuentry "Melvix" {
+    multiboot /boot/kernel.bin
+    boot
+}
\ No newline at end of file
diff --git a/src/bootloader/hdd1.asm b/src/bootloader/hdd1.asm
deleted file mode 100644
index 514deca..0000000
--- a/src/bootloader/hdd1.asm
+++ /dev/null
@@ -1,118 +0,0 @@
-BITS 16
-ORG 0x7C00
-
-%define INODE_ADDRESS 0xF000
-%define INODE_NBLOCKS 20
-%define INODE_DBP0 24
-
-; Save the boot drive id
-mov [bootDriveID], dl
-
-jmp start
-
-print:
-    mov ah, 0x0E
-    xor bh, bh
-    .print_L:
-        lodsb
-        test al, al
-        jz .print_end
-        int 0x10
-        jmp .print_L
-    .print_end:
-    ret
-
-bootDriveID: db 0
-
-dapack:
-    dapack_size: db 0x10
-    dapack_null: db 0x00
-    dapack_blkcount: dw 0x0001
-    dapack_boffset: dw 0x8000
-    dapack_bsegment: dw 0x0000
-    dapack_start: dd 0x00000000
-    dapack_upper_lba_bits: dd 0x00000000
-
-readsector:
-    mov dword [dapack_start], eax
-    mov ah, 0x42
-    mov dl, [bootDriveID]
-    xor bx, bx
-    mov ds, bx
-    mov si, dapack
-    int 0x13
-    ret
-
-; 5K max
-readwholefile:
-    mov bx, word [dapack_boffset]
-    push bx
-    mov bx, INODE_ADDRESS
-    mov word [dapack_boffset], bx
-    call readsector
-    pop bx
-    mov word [dapack_boffset], bx
-
-    mov edx, [INODE_ADDRESS+INODE_NBLOCKS]
-
-    xor ecx, ecx
-    .readwholefile_L:
-        lea bx, [INODE_ADDRESS + INODE_DBP0 + (ecx*4)]
-        mov eax, dword [bx]
-
-        push dx
-        call readsector
-        pop dx
-
-        add dword [dapack_boffset], 512
-
-        inc cx
-        cmp cx, dx
-        jl .readwholefile_L
-    ret
-
-welcome db "Melvix", 0x0A, 0x0D, 0x00
-nolba db "BIOS lacks support for lba addressing.", 0x00
-signaturebad db "Bad disk signature.", 0x00
-
-start:
-    mov ax, 0x0003
-    int 0x10
-
-    mov si, welcome
-    call print
-
-    mov ah, 0x41
-    mov bx, 0x55AA
-    int 0x13
-    jc lba_not_supported
-    cmp bx, 0xAA55
-    jnz lba_not_supported
-
-    mov eax, 1
-    call readsector
-
-    mov eax, [0x8000+0]
-    cmp eax, 0x34B59645
-    jnz signature_BAD
-    mov eax, [0x8000+4]
-    cmp eax, 0x1083B99F
-    jnz signature_BAD
-
-    mov eax, 2
-    call readwholefile
-
-    jmp 0x8000
-
-lba_not_supported:
-    mov si, nolba
-    call print
-    jmp $
-
-signature_BAD:
-    mov si, signaturebad
-    call print
-    jmp $
-
-times 510-($-$$) db 0
-dw 0xAA55
\ No newline at end of file
diff --git a/src/bootloader/hdd2.asm b/src/bootloader/hdd2.asm
deleted file mode 100644
index db5aa38..0000000
--- a/src/bootloader/hdd2.asm
+++ /dev/null
@@ -1,388 +0,0 @@
-BITS 16
-ORG 0x8000
-
-%define SECTOR_BUFFER 0x9000
-%define INODE_NBLOCKS 20
-%define INODE_DBP0 24
-%define INODE_SIBP 64
-%define INODE_DIBP 68
-%define INODE_TIBP 72
-%define INODE_QIBP 76
-
-mov esp, 0xFFFF
-jmp start
-
-checkA20:
-    ; Stolen from https://wiki.osdev.org/A20_Line
-    pushf
-    push ds
-    push es
-    push di
-    push si
-    cli
-    xor ax, ax
-    mov es, ax
-    not ax
-    mov ds, ax
-    mov di, 0x0500
-    mov si, 0x0510
-    mov al, byte [es:di]
-    push ax
-    mov al, byte [ds:si]
-    push ax
-    mov byte [es:di], 0x00
-    mov byte [ds:si], 0xFF
-    cmp byte [es:di], 0xFF
-    pop ax
-    mov byte [ds:si], al
-    pop ax
-    mov byte [es:di], al
-    mov ax, 0
-    jz checkA20_exit
-    mov ax, 1
-    checkA20_exit:
-    pop si
-    pop di
-    pop es
-    pop ds
-    popf
-    ret
-
-last_max_level db 0
-getrecursive:
-    push edi
-    push esi
-    push ecx
-
-    mov eax, edi
-    cmp al, byte [last_max_level]
-    jna .last_max_level_updated
-    mov byte [last_max_level], al
-    .last_max_level_updated:
-
-    mov eax, esi
-    call 0x7c26
-
-    mov eax, dword [esp]
-    sub eax, 10
-
-    cmp byte [last_max_level], 1
-    jna .check1
-    mov ebx, 1
-    shl ebx, 7
-    sub eax, ebx
-    .check1:
-        cmp byte [last_max_level], 2
-        jna .check2
-        mov ebx, 1
-        shl ebx, 14
-        sub eax, ebx
-    .check2:
-        cmp byte [last_max_level], 3
-        jna .check3
-        mov ebx, 1
-        shl ebx, 21
-        sub eax, ebx
-    .check3:
-        mov ecx, dword [esp+8]
-        dec ecx
-        push ecx
-        shl ecx, 3
-        sub ecx, dword [esp]
-        add esp, 4
-        shr eax, cl
-
-        mov eax, dword [SECTOR_BUFFER+(4*eax)]
-
-        cmp dword [esp+8], 1
-        jna .finish_recursion
-        mov edi, [esp+8]
-        dec edi
-        mov esi, eax
-        mov ecx, [esp]
-        call getrecursive
-    .finish_recursion:
-        mov byte [last_max_level], 0
-
-        pop ecx
-        pop esi
-        pop edi
-        ret
-
-get_block:
-    push ecx
-    push ebx
-
-    xor ebx, ebx
-    inc ebx
-    shl ebx, 21
-    add ebx, 9
-    cmp ecx, ebx
-    jna .gtb1
-
-    mov edi, 4
-    mov esi, dword [SECTOR_BUFFER+INODE_QIBP]
-    call getrecursive
-    jmp .get_block_end
-
-    .gtb1:
-        xor ebx, ebx
-        inc ebx
-        shl ebx, 14
-        add ebx, 9
-        cmp ecx, ebx
-        jna .gtb2
-
-        mov edi, 3
-        mov esi, dword [SECTOR_BUFFER+INODE_TIBP]
-        call getrecursive
-        jmp .get_block_end
-
-    .gtb2:
-        xor ebx, ebx
-        inc ebx
-        shl ebx, 7
-        add ebx, 9
-        cmp ecx, ebx
-        jna .gtb3
-
-        mov edi, 2
-        mov esi, dword [SECTOR_BUFFER+INODE_DIBP]
-        call getrecursive
-        jmp .get_block_end
-
-    .gtb3:
-        cmp ecx, 9
-        jna .gtb4
-
-        mov edi, 1
-        mov esi, dword [SECTOR_BUFFER+INODE_SIBP]
-        call getrecursive
-        jmp .get_block_end
-
-    .gtb4:
-        mov eax, SECTOR_BUFFER+INODE_DBP0
-        mov eax, dword [eax+(4*ecx)]
-
-    .get_block_end:
-        pop ebx
-        pop ecx
-        ret
-
-noa20 db "A20 could not be enabled.", 0
-loading db "Loading kernel...", 0x0A, 0x0D, 0x00
-booting db "Booting...", 0x0A, 0x0D, 0x00
-nomem db "BIOS does not support memory detection!", 0
-memno20 db "BIOS returns memory detection with 24 bytes. This has never been seen!", 0
-
-start:
-    call checkA20
-    test ax, ax
-    jnz A20_ENABLED
-
-    in al, 0x92
-    or al, 2
-    out 0x92, al
-
-    call checkA20
-    test ax, ax
-    jnz A20_ENABLED
-
-    mov si, noa20
-    call 0x7c07
-    jmp $
-
-A20_ENABLED:
-    ; Inspired by https://wiki.osdev.org/Unreal_Mode
-    cli
-    push ds
-    lgdt [gdtinfo]
-
-    mov eax, cr0
-    or al, 1
-    mov cr0, eax
-
-    jmp $+2
-
-    mov bx, 0x08
-    mov ds, bx
-
-    and al, 0xFE
-    mov cr0, eax
-    pop ds
-
-    mov si, loading
-    call 0x7c07
-
-    mov word [0x7c1a], SECTOR_BUFFER
-
-    mov eax, 3
-    call 0x7c26
-    mov edx, dword [SECTOR_BUFFER + INODE_NBLOCKS]
-
-    xor ecx, ecx
-LOAD_KERNEL:
-    push edx
-
-    mov eax, 3
-    call 0x7c26
-    call get_block
-    call 0x7c26
-
-    mov eax, ecx
-    shl eax, 9
-    add eax, 0x200000
-
-    push ecx
-    xor ecx, ecx
-    .LOAD_KERNEL_L:
-        mov ebx, ecx
-        add ebx, SECTOR_BUFFER
-        mov ebx, dword [ebx]
-
-        mov edx, ebx
-        mov ebx, eax
-        add ebx, ecx
-        mov dword [ebx], edx
-
-        add ecx, 4
-        cmp ecx, 2048
-        jl .LOAD_KERNEL_L
-    pop ecx
-
-    inc ecx
-    pop edx
-    cmp ecx, edx
-    jl LOAD_KERNEL
-
-mov si, booting
-call 0x7c07
-
-mov dl, [0x7c15]
-mov byte [0x9000], dl
-
-mov di, 0xA000
-mov eax, 0xE820
-xor ebx, ebx
-mov ecx, 24
-mov edx, 0x534D4150
-int 0x15
-
-jc BIOS_NO_MEM
-cmp eax, 0x534D4150
-jnz BIOS_NO_MEM
-cmp cl, 20
-jnz BIOS_MEM_NO20
-
-MEM_L:
-    test ebx, ebx
-    jz MEM_FINISHED
-
-    mov ax, di
-    xor ch, ch
-    add ax, cx
-    mov di, ax
-
-    mov eax, 0xE820
-    mov ecx, 24
-    int 0x15
-    jmp MEM_L
-
-MEM_FINISHED:
-    mov eax, cr0
-    or al, 1
-    mov cr0, eax
-
-    mov ax, 0x08
-    mov ds, ax
-    mov es, ax
-    mov fs, ax
-    mov gs, ax
-    mov ss, ax
-
-; Infomation: https://wiki.osdev.org/ELF
-mov ebx, 0x20002C
-mov dl, byte [ebx]
-push dx
-
-mov ebx, 0x20001C
-mov ebx, dword [ebx]
-push ebx
-
-xor dh, dh
-PHT:
-    xor eax, eax
-    mov al, dh
-    shl eax, 5
-    add eax, dword [esp]
-    add eax, 0x200000
-    mov ebx, eax
-
-    mov eax, dword [ebx]
-    cmp eax, 1
-    jnz .PHT_ignore
-
-    add ebx, 4
-    mov eax, dword [ebx]
-    add eax, 0x200000
-    push eax
-
-    add ebx, 4
-    mov eax, dword [ebx]
-    push eax
-
-    add ebx, 8
-    mov eax, dword [ebx]
-    push eax
-
-    push dx
-    xor ecx, ecx
-    .MOVE_KERNEL_L:
-        mov ebx, [esp+10]
-        add ebx, ecx
-        mov ebx, dword [ebx]
-
-        mov eax, ebx
-        mov ebx, dword [esp+6]
-        add ebx, ecx
-        mov dword [ebx], eax
-
-        add ecx, 4
-        cmp ecx, dword [esp+2]
-        jl .MOVE_KERNEL_L
-    pop dx
-    add esp, 12
-
-    .PHT_ignore:
-        inc dh
-        cmp dh, dl
-        jl PHT
-
-jmp (codedesc - gdt):protectedMode
-
-protectedMode:
-    BITS 32
-    mov ebx, 0x100000
-    mov eax, dword [ebx]
-    jmp eax
-
-BITS 16
-BIOS_NO_MEM:
-    mov si, nomem
-    call 0x7c07
-    jmp $
-BIOS_MEM_NO20:
-    mov si, memno20
-    call 0x7c07
-    jmp $
-
-gdtinfo:
-    dw gdt_end - gdt - 1
-    dd gdt
-    gdt dd 0, 0
-    flatdesc db 0xff, 0xff, 0, 0, 0, 10010010b, 11001111b, 0
-    codedesc db 0xff, 0xff, 0, 0, 0, 10011010b, 11001111b, 0
-    gdt_end:
-
-kernelbin db "KERNEL.BIN", 0x3B, "1"
-kernelbin_len equ ($ - kernelbin)
\ No newline at end of file
diff --git a/src/kernel/acpi/acpi.c b/src/kernel/acpi/acpi.c
index 57ecc58..e129a95 100644
--- a/src/kernel/acpi/acpi.c
+++ b/src/kernel/acpi/acpi.c
@@ -166,10 +166,10 @@ int acpi_install()
 			}
 			if (memcmp((unsigned int *)*ptr, "HPET", 4) == 0) {
 				hpet = (struct HPET *)*ptr;
-				serial_printf("%c%c%c%c", hpet->signature[0], hpet->signature[1],
-					      hpet->signature[2], hpet->signature[3]);
-				serial_printf("%d", hpet->legacy_replacement);
-				serial_printf("%d", hpet->address.address);
+				//serial_printf("%c%c%c%c", hpet->signature[0], hpet->signature[1],
+				//hpet->signature[2], hpet->signature[3]);
+				//serial_printf("%d", hpet->legacy_replacement);
+				//serial_printf("%d", hpet->address.address);
 			}
 			ptr++;
 		} // Else: no valid FADT present
diff --git a/src/kernel/boot.asm b/src/kernel/boot.asm
index 06411ea..968a824 100644
--- a/src/kernel/boot.asm
+++ b/src/kernel/boot.asm
@@ -1,3 +1,15 @@
+%define ALIGN    1 ; Align loaded modules on page boundaries
+%define MEMINFO  2 ; Provide memory map
+%define FLAGS    3 ; Flags (ALIGN | MEMINFO)
+%define MAGIC    0x1BADB002
+%define CHECKSUM -(MAGIC + FLAGS)
+
+section .multiboot
+    align 4
+    dd MAGIC
+    dd FLAGS
+    dd CHECKSUM
+
 section .start_section
     dd _start
 
@@ -15,7 +27,9 @@ section .text
     global _start
     extern kernel_main
     _start:
-        push esp
+        mov esp, STACK_TOP
+        push ebx
+        push eax
         cli
         call kernel_main
         cli
diff --git a/src/kernel/fs/load.c b/src/kernel/fs/load.c
index b717e4f..49d31e1 100644
--- a/src/kernel/fs/load.c
+++ b/src/kernel/fs/load.c
@@ -13,8 +13,7 @@ void load_binaries()
 	userspace = (uint32_t)kmalloc(10000);
 	font = (struct font *)kmalloc(100000); // High quality shit
 
-	uint8_t boot_drive_id = (uint8_t)(*((uint8_t *)0x9000));
-	if (boot_drive_id != 0xE0) {
+	if (multiboot_header->boot_device != 0xE0FFFFFF) {
 		struct ata_interface *primary_master = new_ata(1, 0x1F0);
 		marfs_init(primary_master);
 		marfs_read_whole_file(4, (uint8_t *)userspace);
@@ -33,6 +32,11 @@ void load_binaries()
 			panic("Userspace binary not found!");
 		ATAPI_granular_read(1 + (user_e->length / 2048), user_e->lba, (uint8_t *)userspace);
 		kfree(user_e);
+
+		if (font->magic != 0xf0f0f0f0) {
+			serial_printf("0x%x: WRONG FONT MAGIC!", font->magic);
+			halt_loop();
+		}
 	}
 	vga_log("Successfully loaded binaries");
 }
\ No newline at end of file
diff --git a/src/kernel/fs/load.h b/src/kernel/fs/load.h
index 3730b0b..d4833ce 100644
--- a/src/kernel/fs/load.h
+++ b/src/kernel/fs/load.h
@@ -12,6 +12,7 @@ struct font {
 	uint16_t font_24[758][24];
 	uint8_t font_16[758][16];
 	uint16_t cursor[19];
+	uint32_t magic;
 };
 
 void load_binaries();
diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index 80439bc..d06ea4d 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -1,3 +1,4 @@
+#include <kernel/multiboot.h>
 #include <kernel/graphics/vesa.h>
 #include <kernel/gdt/gdt.h>
 #include <kernel/interrupts/interrupts.h>
@@ -15,20 +16,24 @@
 #include <kernel/fs/elf.h>
 #include <kernel/lib/stdio.h>
 
-void kernel_main(uint32_t initial_stack)
+void kernel_main(uint32_t magic, multiboot_info_t *grub_header)
 {
-	initial_esp = initial_stack;
+	if (magic != MULTIBOOT_BOOTLOADER_MAGIC) {
+		vga_log("Invalid boot magic!");
+		halt_loop();
+	}
 	vga_log("Installing basic features of Melvix...");
 
 	// Install features
-	memory_init();
 	gdt_install();
 	init_serial();
 	acpi_install();
 	idt_install();
 	isrs_install();
 	irq_install();
+	memory_init(grub_header);
 	paging_install();
+	memory_print();
 
 	load_binaries();
 	set_optimal_resolution();
@@ -49,6 +54,7 @@ void kernel_main(uint32_t initial_stack)
 
 	// Print total memory
 	info("Total memory found: %dMiB", (memory_get_all() >> 10) + 1);
+	serial_printf("Total memory found: %dMiB", (memory_get_all() >> 10) + 1);
 
 #ifdef INSTALL_MELVIX
 #include <kernel/fs/install.h>
@@ -57,12 +63,12 @@ void kernel_main(uint32_t initial_stack)
 		install_melvix();
 #endif
 
-	load_elf((char *)userspace);
+	// load_elf((char *)userspace);
 
 	// syscalls_install();
 	// exec(userspace);
 
-	panic("This should NOT happen!");
+	// panic("This should NOT happen!");
 
 	// asm ("div %0" :: "r"(0)); // Exception testing x/0
 }
\ No newline at end of file
diff --git a/src/kernel/lib/lib.h b/src/kernel/lib/lib.h
index b2b7056..ae8ee9c 100644
--- a/src/kernel/lib/lib.h
+++ b/src/kernel/lib/lib.h
@@ -3,6 +3,7 @@
 
 #include <stddef.h>
 #include <stdint.h>
+#include <kernel/multiboot.h>
 
 /**
  * Copy n data from src to dest
@@ -31,7 +32,9 @@ void *memset(void *dest, char val, size_t count);
  */
 int memcmp(const void *a_ptr, const void *b_ptr, size_t size);
 
-void memory_init();
+void memory_init(multiboot_info_t *grub_header);
+
+void memory_print();
 
 uint32_t memory_get_all();
 
diff --git a/src/kernel/lib/memory.c b/src/kernel/lib/memory.c
index f9e0054..4763ca0 100644
--- a/src/kernel/lib/memory.c
+++ b/src/kernel/lib/memory.c
@@ -1,5 +1,9 @@
 #include <stddef.h>
 #include <stdint.h>
+#include <kernel/system.h>
+#include <kernel/lib/stdio.h>
+#include <kernel/memory/paging.h>
+#include <kernel/multiboot.h>
 
 void *memcpy(void *dest, const void *src, size_t count)
 {
@@ -31,39 +35,29 @@ int memcmp(const void *a_ptr, const void *b_ptr, size_t size)
 	return 0;
 }
 
-uint32_t total_memory;
+multiboot_info_t *multiboot_header;
 
-struct memory_entry {
-	uint64_t base;
-	uint64_t length;
-	uint32_t type;
-} __attribute__((packed));
-
-struct memory_entry *memory_get_entries()
+void memory_print()
 {
-	return (struct memory_entry *)0xA000;
+	if (multiboot_header->flags & MULTIBOOT_INFO_MEMORY) {
+		serial_printf("Mem lower: 0x%x", multiboot_header->mem_lower);
+		serial_printf("Mem upper: 0x%x", multiboot_header->mem_upper);
+	} else {
+		serial_printf("No memory information available!");
+	}
 }
 
-void memory_init()
+void memory_init(multiboot_info_t *grub_header)
 {
-	uint64_t max_base = 0;
-	uint64_t max_length = 0;
-	for (struct memory_entry *i = memory_get_entries(); i->type; i++) {
-		if (i->type == 1 && i->base > max_base) {
-			max_base = i->base;
-			max_length = i->length;
-		}
-	}
-	total_memory = (uint32_t)(max_base + max_length);
-	total_memory /= 1024;
+	multiboot_header = grub_header;
 }
 
 uint32_t memory_get_free()
 {
-	return total_memory; // - paging_get_used_pages() * 4;
+	return multiboot_header->mem_upper - paging_get_used_pages() * 4;
 }
 
 uint32_t memory_get_all()
 {
-	return total_memory;
+	return multiboot_header->mem_upper;
 }
\ No newline at end of file
diff --git a/src/kernel/linker.ld b/src/kernel/linker.ld
index 50edc46..ff04c17 100644
--- a/src/kernel/linker.ld
+++ b/src/kernel/linker.ld
@@ -4,6 +4,7 @@ SECTIONS {
 	. = 1M;
 
 	.text BLOCK(4K) : ALIGN(4K) {
+		*(.multiboot)
 		*(.start_section)
 		*(.text)
 	}
diff --git a/src/kernel/memory/paging.c b/src/kernel/memory/paging.c
index a29d7db..8b5de59 100644
--- a/src/kernel/memory/paging.c
+++ b/src/kernel/memory/paging.c
@@ -2,6 +2,7 @@
 #include <kernel/memory/paging.h>
 #include <kernel/system.h>
 #include <kernel/lib/lib.h>
+#include <kernel/io/io.h>
 
 int paging_enabled = 0;
 
@@ -40,7 +41,6 @@ void paging_install()
 	paging_set_used(0, ((uint32_t)ASM_KERNEL_END >> 12) + 1); // /4096
 
 	paging_enable();
-
 	vga_log("Installed paging");
 }
 
diff --git a/src/kernel/multiboot.h b/src/kernel/multiboot.h
new file mode 100644
index 0000000..5a98a00
--- /dev/null
+++ b/src/kernel/multiboot.h
@@ -0,0 +1,216 @@
+/* multiboot.h - Multiboot header file. */
+/* Copyright (C) 1999,2003,2007,2008,2009  Free Software Foundation, Inc.
+  *
+  *  Permission is hereby granted, free of charge, to any person obtaining a copy
+  *  of this software and associated documentation files (the "Software"), to
+  *  deal in the Software without restriction, including without limitation the
+  *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+  *  sell copies of the Software, and to permit persons to whom the Software is
+  *  furnished to do so, subject to the following conditions:
+  *
+  *  The above copyright notice and this permission notice shall be included in
+  *  all copies or substantial portions of the Software.
+  *
+  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL ANY
+  *  DEVELOPER OR DISTRIBUTOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+  *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+  *  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+  */
+
+#ifndef MULTIBOOT_HEADER
+#define MULTIBOOT_HEADER 1
+
+/* How many bytes from the start of the file we search for the header. */
+#define MULTIBOOT_SEARCH 8192
+
+/* The magic field should contain this. */
+#define MULTIBOOT_HEADER_MAGIC 0x1BADB002
+
+/* This should be in %eax. */
+#define MULTIBOOT_BOOTLOADER_MAGIC 0x2BADB002
+
+/* The bits in the required part of flags field we don't support. */
+#define MULTIBOOT_UNSUPPORTED 0x0000fffc
+
+/* Alignment of multiboot modules. */
+#define MULTIBOOT_MOD_ALIGN 0x00001000
+
+/* Alignment of the multiboot info structure. */
+#define MULTIBOOT_INFO_ALIGN 0x00000004
+
+/* Flags set in the 'flags' member of the multiboot header. */
+
+/* Align all boot modules on i386 page (4KB) boundaries. */
+#define MULTIBOOT_PAGE_ALIGN 0x00000001
+
+/* Must pass memory information to OS. */
+#define MULTIBOOT_MEMORY_INFO 0x00000002
+
+/* Must pass video information to OS. */
+#define MULTIBOOT_VIDEO_MODE 0x00000004
+
+/* This flag indicates the use of the address fields in the header. */
+#define MULTIBOOT_AOUT_KLUDGE 0x00010000
+
+/* Flags to be set in the 'flags' member of the multiboot info structure. */
+
+/* is there basic lower/upper memory information? */
+#define MULTIBOOT_INFO_MEMORY 0x00000001
+/* is there a boot device set? */
+#define MULTIBOOT_INFO_BOOTDEV 0x00000002
+/* is the command-line defined? */
+#define MULTIBOOT_INFO_CMDLINE 0x00000004
+/* are there modules to do something with? */
+#define MULTIBOOT_INFO_MODS 0x00000008
+
+/* These next two are mutually exclusive */
+
+/* is there a symbol table loaded? */
+#define MULTIBOOT_INFO_AOUT_SYMS 0x00000010
+/* is there an ELF section header table? */
+#define MULTIBOOT_INFO_ELF_SHDR 0X00000020
+
+/* is there a full memory map? */
+#define MULTIBOOT_INFO_MEM_MAP 0x00000040
+
+/* Is there drive info? */
+#define MULTIBOOT_INFO_DRIVE_INFO 0x00000080
+
+/* Is there a config table? */
+#define MULTIBOOT_INFO_CONFIG_TABLE 0x00000100
+
+/* Is there a boot loader name? */
+#define MULTIBOOT_INFO_BOOT_LOADER_NAME 0x00000200
+
+/* Is there a APM table? */
+#define MULTIBOOT_INFO_APM_TABLE 0x00000400
+
+/* Is there video information? */
+#define MULTIBOOT_INFO_VIDEO_INFO 0x00000800
+
+#ifndef ASM_FILE
+
+typedef unsigned short multiboot_uint16_t;
+typedef unsigned int multiboot_uint32_t;
+typedef unsigned long long multiboot_uint64_t;
+
+struct multiboot_header {
+	/* Must be MULTIBOOT_MAGIC - see above. */
+	multiboot_uint32_t magic;
+
+	/* Feature flags. */
+	multiboot_uint32_t flags;
+
+	/* The above fields plus this one must equal 0 mod 2^32. */
+	multiboot_uint32_t checksum;
+
+	/* These are only valid if MULTIBOOT_AOUT_KLUDGE is set. */
+	multiboot_uint32_t header_addr;
+	multiboot_uint32_t load_addr;
+	multiboot_uint32_t load_end_addr;
+	multiboot_uint32_t bss_end_addr;
+	multiboot_uint32_t entry_addr;
+
+	/* These are only valid if MULTIBOOT_VIDEO_MODE is set. */
+	multiboot_uint32_t mode_type;
+	multiboot_uint32_t width;
+	multiboot_uint32_t height;
+	multiboot_uint32_t depth;
+};
+
+/* The symbol table for a.out. */
+struct multiboot_aout_symbol_table {
+	multiboot_uint32_t tabsize;
+	multiboot_uint32_t strsize;
+	multiboot_uint32_t addr;
+	multiboot_uint32_t reserved;
+};
+typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;
+
+/* The section header table for ELF. */
+struct multiboot_elf_section_header_table {
+	multiboot_uint32_t num;
+	multiboot_uint32_t size;
+	multiboot_uint32_t addr;
+	multiboot_uint32_t shndx;
+};
+typedef struct multiboot_elf_section_header_table multiboot_elf_section_header_table_t;
+
+struct multiboot_info {
+	/* Multiboot info version number */
+	multiboot_uint32_t flags;
+
+	/* Available memory from BIOS */
+	multiboot_uint32_t mem_lower;
+	multiboot_uint32_t mem_upper;
+
+	/* "root" partition */
+	multiboot_uint32_t boot_device;
+
+	/* Kernel command line */
+	multiboot_uint32_t cmdline;
+
+	/* Boot-Module list */
+	multiboot_uint32_t mods_count;
+	multiboot_uint32_t mods_addr;
+
+	union {
+		multiboot_aout_symbol_table_t aout_sym;
+		multiboot_elf_section_header_table_t elf_sec;
+	} u;
+
+	/* Memory Mapping buffer */
+	multiboot_uint32_t mmap_length;
+	multiboot_uint32_t mmap_addr;
+
+	/* Drive Info buffer */
+	multiboot_uint32_t drives_length;
+	multiboot_uint32_t drives_addr;
+
+	/* ROM configuration table */
+	multiboot_uint32_t config_table;
+
+	/* Boot Loader Name */
+	multiboot_uint32_t boot_loader_name;
+
+	/* APM table */
+	multiboot_uint32_t apm_table;
+
+	/* Video */
+	multiboot_uint32_t vbe_control_info;
+	multiboot_uint32_t vbe_mode_info;
+	multiboot_uint16_t vbe_mode;
+	multiboot_uint16_t vbe_interface_seg;
+	multiboot_uint16_t vbe_interface_off;
+	multiboot_uint16_t vbe_interface_len;
+};
+typedef struct multiboot_info multiboot_info_t;
+
+struct multiboot_mmap_entry {
+	multiboot_uint32_t size;
+	multiboot_uint64_t addr;
+	multiboot_uint64_t len;
+#define MULTIBOOT_MEMORY_AVAILABLE 1
+#define MULTIBOOT_MEMORY_RESERVED 2
+	multiboot_uint32_t type;
+} __attribute__((packed));
+typedef struct multiboot_mmap_entry multiboot_memory_map_t;
+
+struct multiboot_mod_list {
+	/* the memory used goes from bytes 'mod_start' to 'mod_end-1' inclusive */
+	multiboot_uint32_t mod_start;
+	multiboot_uint32_t mod_end;
+
+	/* Module command line */
+	multiboot_uint32_t cmdline;
+
+	/* padding to take it to 16 bytes (must be zero) */
+	multiboot_uint32_t pad;
+};
+typedef struct multiboot_mod_list multiboot_module_t;
+
+#endif /* ! ASM_FILE */
+
+#endif /* ! MULTIBOOT_HEADER */
\ No newline at end of file
diff --git a/src/kernel/system.c b/src/kernel/system.c
index b58472b..c58949e 100644
--- a/src/kernel/system.c
+++ b/src/kernel/system.c
@@ -28,6 +28,7 @@ void vga_log(char *msg)
 	uint16_t *terminal_buffer = (uint16_t *)0xB8000;
 	for (size_t i = 0; i < strlen(msg); i++)
 		terminal_buffer[line * 80 + i] = (uint16_t)msg[i] | (uint16_t)0x700;
+	serial_printf(msg);
 	char string[80];
 	strcpy(string, "[");
 	strcat(string, itoa((int)get_time()));
diff --git a/src/kernel/system.h b/src/kernel/system.h
index 687649f..90535f6 100644
--- a/src/kernel/system.h
+++ b/src/kernel/system.h
@@ -3,6 +3,7 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#include <kernel/multiboot.h>
 
 /**
  * The kernel end
@@ -15,6 +16,11 @@ extern void ASM_KERNEL_END();
 uint32_t initial_esp;
 
 /**
+ * Multiboot structure pointer by grub
+ */
+multiboot_info_t *multiboot_header;
+
+/**
  * Initialize the basic features of the OS
  */
 void init();
diff --git a/src/resources/conv.sh b/src/resources/conv.sh
index 36a17d0..8b38016 100755
--- a/src/resources/conv.sh
+++ b/src/resources/conv.sh
@@ -4,7 +4,7 @@
 
 printf "// Generated using the Spleen font and the bdf2c converter (modified using the conv.sh script)\n// Spleen font: (c) 2018-2019, Frederic Cambus, License: MIT\n // bdf2c: (c) 2009-2010 Lutz Sammer, License: AGPLv3\n\n" >font.c
 
-printf "#include <stdint.h>\n\nuint16_t cursor[19]={0b100000000000,0b110000000000,0b111000000000,0b111100000000,0b111110000000,0b111111000000,0b111111100000,0b111111110000,0b111111111000,0b111111111100,0b111111111110,0b111111111111,0b111111111111,0b111111110000,0b111101111000,0b111001111000,0b110000111100,0b000000111100,0b000000011000};\n" >>font.c
+printf "#include <stdint.h>\n\nuint32_t magic=0xf0f0f0f0;\n\nuint16_t cursor[19]={0b100000000000,0b110000000000,0b111000000000,0b111100000000,0b111110000000,0b111111000000,0b111111100000,0b111111110000,0b111111111000,0b111111111100,0b111111111110,0b111111111111,0b111111111111,0b111111110000,0b111101111000,0b111001111000,0b110000111100,0b000000111100,0b000000011000};\n" >>font.c
 
 generate() {
 	font_url="https://raw.githubusercontent.com/fcambus/spleen/master/spleen-$1x$2.bdf"
diff --git a/src/resources/font.c b/src/resources/font.c
index de5dda1..4269b35 100644
--- a/src/resources/font.c
+++ b/src/resources/font.c
@@ -4,6 +4,8 @@
 
 #include <stdint.h>
 
+uint32_t magic = 0xf0f0f0f0;
+
 uint16_t cursor[19] = { 0b100000000000, 0b110000000000, 0b111000000000, 0b111100000000,
 			0b111110000000, 0b111111000000, 0b111111100000, 0b111111110000,
 			0b111111111000, 0b111111111100, 0b111111111110, 0b111111111111,