diff options
| -rw-r--r-- | .gitignore | 3 | ||||
| -rwxr-xr-x | boot.asm | 117 | ||||
| -rwxr-xr-x | makefile | 12 |
3 files changed, 132 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..bc15830 --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +*.bin +*.iso +*.flp diff --git a/boot.asm b/boot.asm new file mode 100755 index 0000000..e687586 --- /dev/null +++ b/boot.asm @@ -0,0 +1,117 @@ +[org 0x7c00] + +;main code----------------------------------------------------- + +mov bp, 0x8000 +mov sp, bp + +mov si, msg +call print + +mov bx, 0x9000 ;where to load (ES:BX) +mov dh, 0x02 +mov dl, [boot_drive] +call disk_load + +mov dx, [0x9000] +call print_hex + +mov dx, [0x9200] +call print_hex + +;hang-------------------------- +cli +jmp $ + +;functions----------------------------------------------------- + +;print------------------------------------------- +print: +pusha +mov ah, 0x0e ;teletype output +a: +mov al, [si] ;char to print +cmp al, 0x0 +je b +int 0x10 +inc si +jmp a +b: +popa +ret + +;print_hex--------------------------------------- +print_hex: +pusha +;manipulate hex_out---------- +mov bx, dx +shr bx, 12 +and bx, 0x000f +mov bx, [hex + bx] +mov [hex_out + 2], bl + +mov bx, dx +shr bx, 8 +and bx, 0x000f +mov bx, [hex + bx] +mov [hex_out + 3], bl + +mov bx, dx +shr bx, 4 +and bx, 0x000f +mov bx, [hex + bx] +mov [hex_out + 4], bl + +mov bx, dx +shr bx, 0 +and bx, 0x000f +mov bx, [hex + bx] +mov [hex_out + 5], bl +;end of manipulation--------- +mov si, hex_out +call print +popa +ret + +;load to memory------------------------------------------------ +disk_load: +pusha +push dx ;save to cmp later +;dh-num_sec, dl-floppy/hdd/cd +mov ah, 0x02 ;read sectors from drive +mov al, dh ;number of sectors to read +mov dh, 0x00 ;head +mov ch, 0x00 ;cylinder +mov cl, 0x02 ;sector (second sector) +int 0x13 + +jc disk_err +pop dx +cmp dh, al +jne disk_err + +popa +ret + +disk_err: +mov si, lerr +call print +mov dx, ax +call print_hex +cli +jmp $ + +;data---------------------------------------------------------- +msg: db "Data loaded from boot drive:", 0x0a, 0x0d, 0x0 +hex_out: db "0x0000", 0x0a, 0x0d, 0x0 +hex: db "0123456789ABCDEF" +lerr: db "Error: INT 13H -> AX: ", 0x0 +boot_drive: db 0x80 ;floppy-iso(0x00) or hdd-qemu(0x80) + +;boot number--------------------------------------------------- +times 510-($-$$) db 0 +dw 0xaa55 + +;other sectors------------------------------------------------- +times 256 dw 0xb10c +times 256 dw 0xcafe diff --git a/makefile b/makefile new file mode 100755 index 0000000..f181ac6 --- /dev/null +++ b/makefile @@ -0,0 +1,12 @@ +boot.bin: boot.asm + nasm -f bin boot.asm -o boot.bin +all: boot.bin + truncate boot.bin -s 1200k + mkisofs -o boot.iso -b boot.bin ./ + dd if=boot.bin of=boot.flp bs=512 count=2880 +clean: + rm boot.bin + rm boot.iso + rm boot.flp +run: boot.bin + qemu-system-x86_64 boot.bin |