0.326s-boot: enable long-mode but no kernel

LINES

+2021-2-8 0.326: 326 lines, 2 files

boot/Makefile

+remake: 
+	echo "*** If there isn't 'bootloader.bin', use 'make first' ***"
+	rm bootloader.bin
+	make cunix.img
+
+first: 
+	make cunix.img
+
+boot.bin: boot.asm
+	nasm boot.asm -o boot.bin
+
+loader.bin: loader.asm
+	nasm loader.asm -o loader.bin
+
+bootloader.bin: boot.bin loader.bin
+	cat boot.bin loader.bin >> bootloader.bin
+
+cunix.img: bootloader.bin
+	dd if=/dev/zero of=cunix.img bs=1024 count=1440
+	dd if=bootloader.bin of=cunix.img conv=notrunc
+
+
+clear:
+	rm *.bin cunix.img

boot/boot.asm

+; Copyright (C) 2021 Rain
+
+; This file is part of Cunix. 
+; Cunix is free software: you can redistribute it and/or modify 
+; it under the terms of the GNU General Public License as published by 
+; the Free Software Foundation, either version 3 of the License, or 
+; (at your option) and later version. 
+
+; Cunix is distributed in the hope that it will be useful, 
+; but WITHOUT ANY WARRANTY; without even the implied warranty of 
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
+; GNU General Public License for more details. 
+
+; You should have received a copy of the GNU General Public License 
+; along with Cunix. If not, see <https://www.gnu.org/licenses/>.  
+
+
+
+
+BI_BOOTDEV equ 0x7e00
+
+org 0x7c00
+
+
+xor ax, ax
+
+mov ds, ax
+mov es, ax
+
+mov ss, ax
+mov sp, 0x7c00
+
+; display message: `Cunix is booting...`
+
+
+; boot device driver number is in DL (by BIOS-19)
+mov [BI_BOOTDEV], dl
+
+
+mov si, message
+call print
+
+call load_loader
+
+jmp 0x0000:0x8000
+
+
+message: db "Cunix is booting...", 0x0d, 0x0a, 0x00
+diskpanic_message: db "read disk failed", 0x0d, 0x0a, 0x00
+panic_message: db "panic: ", 0x00
+
+print:
+	; SI: message address
+	mov al, [si]
+	add si, 1
+
+	cmp al, 0x00
+	je .ret
+
+	mov ah, 0x0e
+	mov bx, 0x0f
+	int 0x10
+
+	jmp print
+
+.ret:
+	ret
+
+
+load_loader:
+	mov ax, 0x0201
+	mov dx, 0x0000
+	mov dl, [BI_BOOTDEV]
+	mov cx, 0x0002
+	mov bx, 0x8000
+	int 0x13
+
+	mov di, diskpanic_message
+
+	jc .try_lba
+
+	ret
+
+.try_lba:
+	mov ax, 0x0002
+	mov cl, 0x0001
+	mov bx, 0x8000
+	call read_lba
+
+	jc panic
+	ret
+
+read_lba:
+	push dword 0x00000000
+	push dword eax
+	push word es
+	push word bx
+	push word cx
+	push word 0x0010
+
+	mov ah, 0x42
+	mov dl, 0x00
+	mov si, sp
+	int 0x13
+	add sp, 0x10
+
+	ret
+
+
+panic:
+	mov si, panic_message
+	call print
+
+	mov si, di
+	call print
+
+	hlt
+	jmp $
+
+
+
+times 510 - ($ - $$) db 0x00
+db 0x55, 0xaa
+

boot/loader.asm

+; Copyright (C) 2021 Rain
+
+; This file is part of Cunix. 
+
+; Cunix is free software: you can redistribute it and/or modify 
+it under the terms of the GNU General Public Licene and published by 
+; the Free Software Foundation, either version 3 of the License, or 
+; (at your option) any later version. 
+
+; Cunix is distributed in the hope that it will be useful, 
+; but WITHOUT ANY WARRANTY; without even the implied warranty of 
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
+; GNU General Public License for more details. 
+
+; You should have recceived a copy of the GNU General Public License 
+; along with Cunix. If not, see <https://www.gnu.org/licenses/>. 
+
+
+
+
+org 0x8000
+
+bits 16
+
+_start:	
+	mov si, message
+	call print
+
+.to_protect_mode:
+	cli
+	lgdt [gdt32_descriptor]
+
+	mov eax, cr0
+	; set CR0.bit 1 (Protect-mode Enable)
+	or eax, 1
+	mov cr0, eax
+
+	jmp dword code32:init_protect_mode
+
+print:
+	mov al, [si]
+	add si, 1
+	
+	cmp al, 0x00
+	je .do_ret
+
+	mov ah, 0x0e
+	mov bx, 0x0f
+
+	int 0x10
+
+	jmp print
+
+.do_ret:
+	ret
+
+bits 32
+
+init_protect_mode:
+	mov ax, 0x10
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+
+	mov ss, ax
+	mov esp, 0x00007c00
+
+.to_long_mode:
+	; page map at 0x7000
+	; set pagemap level-4
+	mov dword [0x70000], 0x71007
+	mov dword [0x70004], 0x00000
+	mov dword [0x70800], 0x70007
+	mov dword [0x70804], 0x00000
+
+	; ...and, page directory pointer table
+	mov dword [0x71000], 0x72007
+	mov dword [0x71008], 0x00000
+
+	; then, page directory entry (2 MB size)
+	mov dword [0x72000], 0x000083
+	mov dword [0x72004], 0x000000
+
+	mov dword [0x72008], 0x200083
+	mov dword [0x7200c], 0x000000
+
+	mov dword [0x72010], 0x400083
+	mov dword [0x72014], 0x000000
+
+	mov dword [0x72018], 0x600083
+	mov dword [0x7201c], 0x000000
+	
+	mov dword [0x72020], 0x800083
+	mov dword [0x72024], 0x000000
+	
+	mov dword [0x72028], 0xa00083
+	mov dword [0x7202c], 0x000000
+	
+	
+
+	lgdt [gdt64_descriptor]
+
+	mov ax, 0x10
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+
+	mov ss, ax
+	mov esp, 0x00007c00
+
+	mov eax, cr4
+	bts eax, 5
+	mov cr4, eax
+
+	; page table
+	mov eax, 0x70000
+	mov cr3, eax
+
+	; enable long-mode before paging
+	mov ecx, 0xc0000080
+	rdmsr
+
+	bts eax, 8
+	wrmsr
+
+	mov eax, cr0
+	or eax, 1
+	bts eax, 31
+	mov cr0, eax
+	
+	
+	jmp code64:init_long_mode
+
+bits 64
+
+init_long_mode:
+	mov ax, 0x10
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+
+	mov ss, ax
+	mov rsp, 0x0000000000007c00
+
+e:
+	hlt
+	jmp e
+	
+
+message: db "Cunix is loading...", 0x0d, 0x0a, 0x00
+t32_message: db "changing to protect mode...", 0x00
+ok_message: db "OK", 0x0d, 0x0a, 0x00
+fail_message: db "FAILED", 0x0d, 0x0a, 0x00
+
+
+display_point: dw 0x0000
+cur_position: db 0x00
+line_position: db 0x00
+
+
+gdt32:
+	dd 0x00000000, 0x00000000
+
+gdt32_code:
+	dd 0x0000ffff, 0x00cf9a00
+
+gdt32_data:
+	dd 0x0000ffff, 0x00cf9200
+
+gdt32_len equ $ - gdt32
+
+gdt32_descriptor:
+	dw gdt32_len - 1
+	dd gdt32
+
+code32 equ gdt32_code - gdt32
+data32 equ gdt32_data - gdt32
+
+
+gdt64:
+	dq 0x0000000000000000
+
+gdt64_code:
+	dq 0x0020980000000000
+
+gdt64_data:
+	dq 0x0000920000000000
+
+gdt64_len equ $ - gdt64
+
+gdt64_descriptor:
+	dw gdt64_len - 1
+	dd gdt64
+
+code64 equ gdt64_code - gdt64
+data64 equ gdt64_data - gdt64
+
+
+