rdos/kernel/main.asm

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cpu 8086
org 0x0000
db 0x55, 0xAA
optrom_length:
db 0x00
jmp optrom_init
str_vendor:
db "Nero", 0
align 16
str_product:
db "Nero DOS", 0
times (0x1A - ($-$$)) db 0
dw pnp
align 16
pnp:
db "$PnP"
db 1 ; version 1
db 2 ; 2 * 16 length
dw 0 ; offset of next header
db 0
db 0 ; checksum (filled by fix-rom)
dd 0 ; device identifier
dw str_vendor ; manufacturer string
dw str_product ; product name string
db 0,0,0 ; device type string
db 0x20 ; device indicator, bit for "read cacheable" set
dw 0 ; boot connection vector
dw 0 ; boot disconnect vector
dw start ; bootstrap entry point
dw 0 ; reserved
dw 0
align 16
optrom_init:
xor ax, ax
mov es, ax
mov di, 0x0060 ; vector (0x18 * 4 bytes)
mov ax, start
stosw
mov ax, cs
stosw
retf
putc:
push bx
push cx
mov ah, 0x0e
mov bx, 0x0000
int 0x10
pop cx
pop bx
ret
announce:
push cs
mov ax, str_product
push ax
call printf
db "%S (CS=%Xh)", 0x0A, 0x0D, 0x00
add sp, 4
ret
start:
mov ax, cs
mov ds, ax
call announce
; clear memory until 0x01000
xor ax, ax
mov es, ax
mov di, 0x500
mov cx, 0xB00
rep stosb
call intr_init
sti
sub sp, 0x10
mov si, sp
mov word [ss:si+0x00], 0
mov word [ss:si+0x02], 1
mov word [ss:si+0x04], 0
mov word [ss:si+0x06], 0x2000
mov word [ss:si+0x08], 0x07fc
mov word [ss:si+0x0A], 0
mov word [ss:si+0x0C], 0
mov word [ss:si+0x0E], 0
mov ah, 0x42
push ss
pop ds
call ramdisk_io
push ax
call printf
db "AX=%X", 0x0A, 0x0D, 0x00
pop ax
add sp, 0x10
.halt:
hlt
jmp .halt
%include "ramdisk.inc"
%include "printf.inc"
%include "intr.asm"
%include "debug.asm"
%include "kprintf.asm"
%include "dosapi.asm"
_reloc_end:
align 512