| 15 | | * Accesso diretto alla macchina fisica `mioboot-nobios-simple.asm` |
| 16 | | {{{ |
| 17 | | bits 16 ; 16 bit real mode |
| 18 | | org 0x7C00 ; origine indirizzo 0000:7C00 |
| 19 | | |
| 20 | | start: |
| 21 | | mov ax, 0xb800 ; text video memory |
| 22 | | mov ds, ax |
| 23 | | mov eax, 10 |
| 24 | | write: |
| 25 | | cmp eax, 0 |
| 26 | | jz end |
| 27 | | mov byte [eax], 'm' |
| 28 | | mov byte [eax+1], 0x0F ; attrib = white on black |
| 29 | | sub eax, 2 |
| 30 | | jmp write |
| 31 | | end: |
| 32 | | hlt |
| 33 | | |
| 34 | | times 510-($-$$) db 0 ; 0-padding |
| 35 | | dw 0xAA55 |
| 36 | | }}} |
| 37 | | {{{ |
| 38 | | #!sh |
| 39 | | nasm -l mioboot-nobios-simple.lst -o mioboot-nobios-simple.img mioboot-nobios-simple.asm |
| 40 | | qemu mioboot-nobios-simple.img |
| 41 | | }}} |
| 42 | | |
| 43 | | |
| 44 | | * Uso dei servizi del BIOS `mioboot.asm` |
| 45 | | {{{ |
| 46 | | bits 16 ; 16 bit real mode |
| 47 | | org 0x7C00 ; origine indirizzo 0000:7C00 |
| 48 | | |
| 49 | | start: |
| 50 | | cld ; clears direction flag (index regs incremented) |
| 51 | | mov si, boot |
| 52 | | call message |
| 53 | | working: |
| 54 | | mov si, work |
| 55 | | call message |
| 56 | | |
| 57 | | call waitenter |
| 58 | | jmp working |
| 59 | | |
| 60 | | message: |
| 61 | | lodsb ; carica un byte da [DS:SI] in AL e inc SI |
| 62 | | cmp al, 0 |
| 63 | | jz done |
| 64 | | mov ah, 0x0E ; write char to screen in text mode |
| 65 | | mov bx, 0 ; BH page number BL foreground color |
| 66 | | int 0x10 ; write AL to screen (BIOS) |
| 67 | | jmp message |
| 68 | | done: ret |
| 69 | | |
| 70 | | boot: db "Loading unuseful system...." , 10, 13, 0 |
| 71 | | work: db "I've done my unuseful stuff!" , 10, 13, 0 |
| 72 | | cont: db "Hit ENTER to continue...", 10, 13, 0 |
| 73 | | wow: db "Great! Hello world!" , 10, 13, 0 |
| 74 | | |
| 75 | | waitenter: mov si, cont |
| 76 | | call message |
| 77 | | mov ah, 0 |
| 78 | | int 0x16 ; Wait for keypress (BIOS) |
| 79 | | cmp al, 'm' |
| 80 | | jz egg |
| 81 | | cmp al, 'b' |
| 82 | | jz basic |
| 83 | | cmp al, 13 |
| 84 | | jnz waitenter |
| 85 | | ret |
| 86 | | egg: mov si, wow |
| 87 | | call message |
| 88 | | jmp waitenter |
| 89 | | basic: int 0x18 ; basic (BIOS) |
| 90 | | hlt |
| 91 | | |
| 92 | | times 510-($-$$) db 0 |
| 93 | | dw 0xAA55 |
| 94 | | }}} |
| | 15 | * Accesso diretto alla macchina fisica source:trunk/mioboot-nobios-simple.asm |
| | 16 | * Uso dei servizi del BIOS source:trunk/mioboot.asm |
| | 17 | |