From ae38fa16c1ee45ccd9acb4a91ad9ccf01955f6a6 Mon Sep 17 00:00:00 2001 From: Michal Idziorek Date: Tue, 19 Aug 2014 09:25:44 +0200 Subject: Added minimal mbr for testing --- boot/test.asm | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 boot/test.asm (limited to 'boot') diff --git a/boot/test.asm b/boot/test.asm new file mode 100644 index 0000000..62110b6 --- /dev/null +++ b/boot/test.asm @@ -0,0 +1,48 @@ +[org 0x7c00] + +[bits 16] +jmp boot_16 ;start boot process + +STR_VERSION: + + db "FoolOs~",0 + +;print_string routine ([bx]) +;this routine will print a null terminated string at [bx] to the screen. +print_string: + + pusha ;push all registers + mov ah,0x0e + + print_string_loop: + + ;check if value at [bx] is "\0" (end of string) + mov cl,[bx] + cmp cl,0 + je print_string_finish + + ;otherwise instruct BIOS to print the current char + mov al,cl + int 0x10 + + ;proceed with next char + inc bx + jmp print_string_loop + + print_string_finish: + + popa ;pop all registers + ret ;return to caller + +boot_16: + + mov bx, STR_VERSION + call print_string + + jmp boot_16 + +times 510-($-$$) db 0 +dw 0xaa55 + + + -- cgit v1.2.3