projects / apple / boot.git / blame
| Commit | Line | Data |
|---|---|---|
| 14c7c974 A |
1 | ; bootnot.asm - boot1 written for turbo assembler, since gas only\r |
| 2 | ; generates 32 bit code and this must run in real mode. | |
| 3 | ; To compile as floppy boot1f.not: | |
| 4 | ; tasm /m3 /dBOOTDEV=FLOPPY boot1 ,boot1f | |
| 5 | ; tlink boot1f | |
| 6 | ; exe2bin boot1f | |
| 7 | ; ren boot1f.bin boot1f.not | |
| 8 | \r | |
| 9 | ;***********************************************************************\r | |
| 10 | ; This is the code for the NeXT boot1 bootsector. | |
| 11 | ;***********************************************************************\r | |
| 12 | \r | |
| 13 | P486 ;enable i386 instructions\r | |
| 14 | IDEAL\r | |
| 15 | SEGMENT CSEG\r | |
| 16 | ASSUME CS:CSEG,DS:CSEG\r | |
| 17 | \r | |
| 18 | SDEBUG = 0\r | |
| 19 | \r | |
| 20 | ;BOOTSEG = 100h ; boot will be loaded at 4k\r | |
| 21 | ;BOOTOFF = 0000h | |
| 22 | BOOTSEG = 00h | |
| 23 | BOOTOFF = 1000h | |
| 24 | BUFSZ = 2000h ; 8K disk transfer buffer\r | |
| 25 | \r\r | |
| 26 | ; This code is a replacement for boot1. It is loaded at 0x0:0x7c00\r | |
| 27 | \r | |
| 28 | start:\r | |
| 29 | mov ax,BOOTSEG | |
| 30 | cli ; interrupts off\r | |
| 31 | mov ss,ax ; set up stack seg\r | |
| 32 | mov sp,0fff0h\r | |
| 33 | sti ; reenable interrupts\r | |
| 34 | ||
| 35 | xor ax,ax | |
| 36 | mov es,ax | |
| 37 | mov ds,ax | |
| 38 | mov si,7C00h | |
| 39 | cld ; so pointers will get updated\r | |
| 40 | mov di,0E000h ; relocate boot program to 0xE000\r | |
| 41 | mov cx,100h ; copy 256x2 bytes\r | |
| 42 | repnz movsw ; move it\r | |
| 43 | off1 = 0E000h + (a1 - start)\r | |
| 44 | jmp FAR 0000:off1 ; jump to a1 in relocated place\r | |
| 45 | ||
| 46 | a1:\r | |
| 47 | mov ax,0E00h\r | |
| 48 | mov ds,ax\r | |
| 49 | mov ax,BOOTSEG\r | |
| 50 | mov es,ax\r | |
| 51 | ||
| 52 | mov si, OFFSET not_boot\r | |
| 53 | call message ; display intro message\r | |
| 54 | ||
| 55 | halt: | |
| 56 | mov ah, 00h | |
| 57 | int 16h | |
| 58 | jmp halt ; get key and loop forever | |
| 59 | \r | |
| 60 | message: ; write the error message in ds:esi | |
| 61 | ; to console\r | |
| 62 | push es\r | |
| 63 | mov ax,ds\r | |
| 64 | mov es,ax\r | |
| 65 | \r | |
| 66 | mov bx, 1 ; bh=0, bl=1 (blue)\r | |
| 67 | cld\r | |
| 68 | \r | |
| 69 | nextb:\r | |
| 70 | lodsb ; load a byte into al\r | |
| 71 | cmp al, 0\r | |
| 72 | je done\r | |
| 73 | mov ah, 0eh ; bios int 10, function 0xe\r | |
| 74 | int 10h ; bios display a byte in tty mode\r | |
| 75 | jmp nextb\r | |
| 76 | done: pop es\r | |
| 77 | ret\r | |
| 78 | \r | |
| 79 | putchr:\r | |
| 80 | push bx\r | |
| 81 | mov bx, 1 ; bh=0, bl=1 (blue)\r | |
| 82 | mov ah, 0eh ; bios int 10, function 0xe\r | |
| 83 | int 10h ; bios display a byte in tty mode\r | |
| 84 | pop bx\r | |
| 85 | ret\r | |
| 86 | \r\r | |
| 87 | \r | |
| 88 | not_boot: | |
| 89 | db 10,13 | |
| 90 | db 'The disk in the floppy disk drive isn''t a startup disk:' | |
| 91 | db 10,13 | |
| 92 | db 'It doesn''t contain ' | |
| 93 | db 'the system files required to start up the computer.' | |
| 94 | db 10,13 | |
| 95 | db 'Please eject this disk and restart the computer' | |
| 96 | db ' with a floppy disk,' | |
| 97 | db 10,13 | |
| 98 | db 'hard disk, or CD-ROM that is a startup disk.' | |
| 99 | db 10,13 | |
| 100 | db 0 | |
| 101 | ||
| 102 | ; the last 2 bytes in the sector contain the signature\r | |
| 103 | d1:\r | |
| 104 | a2 = 510 - (d1 - start)\r | |
| 105 | DB a2 dup (0)\r | |
| 106 | DW 0AA55h\r | |
| 107 | ENDS\r | |
| 108 | END\r |