Initial Commit

.gitignore

@@ -0,0 +1,3 @@
+bin
+mount
+image.bin

makefile

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+CC := gcc
+AS := nasm
+BL_ASFLAGS := -f bin
+
+all: bootloader
+	cp bin/bootloader.bin image.bin
+	qemu-img resize image.bin 512M
+	qemu-system-i386 bin/bootloader.bin --no-reboot --no-shutdown -m 32m -smp 2
+
+bootloader:
+	$(AS) src/bootloader/main.s $(BL_ASFLAGS) -o bin/bootloader.bin
+init:
+	@mkdir mount
+	@mkdir bin
+	@mkdir bin/boot
+	@mkdir bin/kernel
+
+clean:
+	@rm -rf bin/
+	@rm -rf mount/

src/bootloader/main.s

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+org 0x7c00
+
+bits 16
+
+%macro debug 0
+    mov ah, 0xe
+    mov al, 0x41
+    int 0x10
+%endmacro
+
+;TODO:
+;Enable A20 line
+;Enable unreal mode
+;Load GDT
+;Load part2
+;Set video mode
+;get memory map
+;enable paging
+;read filesystem
+;load kernel
+;parse ELF format
+;pass memory and video information to kernel
+;relocate and jump to kernel
+
+jump:
+    jmp short start
+    times 3-($-$$) db 0x90
+fat_bpb:
+    .oem:
+        db "KIMI'SOS"
+    .bytes_per_sector:
+        dw 512
+    .sectors_per_cluster:
+        db 8
+    .reserved_sectors:
+        dw 32
+    .fat_count:
+        db 2
+    .root_dir_entries:
+        dw 0
+    .sectors_in_volume:
+        dw 0
+    .media_type:
+        db 0xf8
+    .sectors_per_fat:
+        dw 0
+    .sectors_per_track:
+        dw 63
+    .heads:
+        dw 8
+    .part_start:
+        dd 0
+    .large_sector_count:
+        dd 1048576
+fat_ebpb32:
+    .sectors_per_fat:
+        dd 1024
+    .flags:
+        dw 0
+    .version:
+        db 0, 1
+    .root_dir_cluster:
+        dd 2 
+    .fs_info_sector:
+        dw 1
+    .backup_boot:
+        dw 0
+    .reserved:
+        times 12 db 0
+    .drive_num:
+        db 0x80
+    .ntflags:
+        db 0
+    .sig:
+        db 0x29
+    .vid_Serial:
+        dd 0
+    .label:
+        db " Kimi's OS "
+    .sysid:
+        db "FAT32   "
+    
+start:
+    mov sp, 0x7000
+    mov bp, 0x7000
+    mov ax, ds
+    xor bx, bx
+    mov ds, bx
+    mov [data.part_seg], ax
+    mov [data.part_off], si
+    jmp 0:set_cs
+set_cs:
+    xor cx, cx
+check_a20:
+    inc cx
+    mov ax, 0xffff
+    mov es, ax
+    mov ax, [es:0x7e0e]
+    cmp ax, [ds:0x7dfe]
+    jne load_gdt
+enable_a20:
+    cmp cx, 4
+    je no_a20
+    cmp cx, 3
+    je .fast_a20
+    cmp cx, 2
+    je .kb_en
+    .bios_en:
+        mov ax, 0x2401
+        int 0x15
+        jmp check_a20
+    .fast_a20:
+        in al, 0x92
+        or al, 2
+        out 0x92, al
+        mov ax, 100000
+        .lp:
+            dec ax
+            cmp ax, 0
+            jge .lp
+        jmp check_a20
+    .kb_en:
+        cli
+        mov al, 0xad
+        out 0x64, al
+
+        call .wait
+        mov al, 0xd0
+        out 0x64, al
+
+        call .wait2
+        in al, 0x60
+        push eax
+
+        call .wait
+        mov al, 0xd1
+        out 0x64, al
+
+        call .wait
+        pop eax
+        or al, 2
+        out 0x60, al
+
+        call .wait
+        mov al, 0xae
+        out 0x64, al
+
+        call .wait
+        sti
+        jmp check_a20
+
+    .wait:
+        in al, 0x64
+        test al,2 
+        jnz .wait
+        ret
+    .wait2:
+        in al, 0x64
+        test al, 1
+        jnz .wait2
+        ret
+
+load_gdt:
+load_part2:
+    jmp $
+no_a20:
+    mov ah, 0xe
+    mov al, 'E'
+    int 0x10
+    jmp $
+DAP:
+    .sz: db 0x10
+    .unused: db 0
+    .read_count: dw 7
+    .offset: dw 0x7e00
+    .segment: dw 0
+    .sector_start:
+        dd 1
+        dd 0
+
+
+data:
+    .boot_disc: db 0
+    .part_seg: dw 0
+    .part_off: dw 0
+
+times 510-($-$$) db 0
+db 0x55, 0xaa
+fs_info:
+    .id: dd 0x41615252 
+    .reserved0: times 480 db 0
+    .sig: dd 0x61417272
+    .last_known_free: dd 0xFFFFFFFF
+    .free_search_start: dd 3
+    .reserved: times 12 db 0
+    .trail: dd 0xAA550000 
+times 1024-($-$$) db 0
+part_2:
+load_part3:
+get_mmap:
+set_video_mode:
+times 4096-($-$$) db 0