diff options
Diffstat (limited to 'boot0')
| -rw-r--r-- | boot0/Makefile | 16 | ||||
| -rw-r--r-- | boot0/mbr.asm | 4 | ||||
| -rw-r--r-- | boot0/print_string_16.asm | 115 |
3 files changed, 133 insertions, 2 deletions
diff --git a/boot0/Makefile b/boot0/Makefile new file mode 100644 index 0000000..e930498 --- /dev/null +++ b/boot0/Makefile @@ -0,0 +1,16 @@ +#master boot record + +include ../Makefile.common + +MBR=mbr.bin + +ASM_SOURCES=$(wildcard *.asm) + +$(MBR): $(ASM_SOURCES) + +clean: + -rm $(MBR) + + + + diff --git a/boot0/mbr.asm b/boot0/mbr.asm index 1673c0c..c0a555d 100644 --- a/boot0/mbr.asm +++ b/boot0/mbr.asm @@ -40,8 +40,8 @@ STR_BOOT: db "Boot drive: ",0 BOOT_DRIVE: db 0xff ; include print and disk load routines -%include "boot/print_string_16.asm" -%include "boot0/disk_load_16.asm" +%include "print_string_16.asm" +%include "disk_load_16.asm" ; Here we start! stage1: diff --git a/boot0/print_string_16.asm b/boot0/print_string_16.asm new file mode 100644 index 0000000..9f81a87 --- /dev/null +++ b/boot0/print_string_16.asm @@ -0,0 +1,115 @@ +[bits 16] + +BLANK: + db 0x12 + +SPACE: + db " ",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 + +print_clear: + +pusha + mov ah,0x6 ;func + mov al,0 ;scroll one line + mov bh,[BLANK] ;blank char + + mov ch,0 ;upper left corner + mov cl,0 + mov dh,20 ;lower right corner + mov dl,40 + int 0x10 + + mov ah,0x2 + mov bh,0 + mov dl,0 + mov dh,20 + int 0x10 +popa + +print_nextline: + + pusha + + mov ah,0x6 ;func + mov al,1 ;scroll one line + mov bh,[BLANK] ;blank char + + mov ch,0 ;upper left corner + mov cl,0 + mov dh,20 ;lower right corner + mov dl,40 + int 0x10 + + + mov ah,0x3 + mov bh,0 + int 0x10 + + + mov ah,0x2 + mov dl,0 + int 0x10 + + mov bx,SPACE + call print_string + + popa + ret + + +;print byte from al to screen + print_hex_byte: + + pusha + + mov [.temp],al + shr al,4 + cmp al,10 + sbb al,69h + das + + mov ah,0Eh + int 10h + + mov al,[.temp] + ror al,4 + shr al,4 + cmp al,10 + sbb al,69h + das + + mov ah,0Eh + int 10h + +popa + + ret + + .temp db 0 |