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k_main()
{

k_clear_screen();

k_printf("Carregado com sucesso...!\n2piv.0.1"", 0);

};

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[BITS 32]

[global start]
[extern _k_main]

start:

  lgdt [gdt_ptr]

  mov ax,LINEAR_DATA_SEL
  mov ds,ax
  mov es,ax
  mov ss,ax
  mov fs,ax
  mov gs,ax

  call _k_main

  jmp $

SECTION .data

gdt:
; NULL descriptor
dw 0; limit 15:0
dw 0; base 15:0
db 0; base 23:16
db 0; type
db 0; limit 19:16, flags
db 0; base 31:24

; unused descriptor
dw 0
dw 0
db 0
db 0
db 0
db 0

LINEAR_DATA_SELequ$-gdt
dw 0FFFFh
dw 0
db 0
db 92h; present, ring 0, data, expand-up, writable
db 0CFh; page-granular (4 gig limit), 32-bit
db 0

LINEAR_CODE_SELequ$-gdt
dw 0FFFFh
dw 0
db 0
db 9Ah; present,ring 0,code,non-conforming,readable
db 0CFh; page-granular (4 gig limit), 32-bit
db 0
gdt_end:

gdt_ptr:
dw gdt_end - gdt - 1
dd gdt

Code: Select all

define WHITE_TXT 0x07



void k_clear_screen()
{

char *vidmem = (char *) 0xb8000;

unsigned int i=0;

while(i < (80*25*2))

{

vidmem[i]=' ';

i++;

vidmem[i]=WHITE_TXT;

i++;

};

};

unsigned int k_printf(char *message, unsigned int line)

{

char *vidmem = (char *) 0xb8000;

unsigned int i=0;



i=(line*80*2);



while(*message!=0)

{

if(*message=='\n')
{

line++;

i=(line*80*2);

*message++;

} else {

vidmem[i]=*message;

*message++;

i++;

vidmem[i]=WHITE_TXT;

i++;

};

};



return(1);

};

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OUTPUT_FORMAT("binary")
ENTRY(start)
SECTIONS
{
  .text  0xFF800000 : {
    *(.text)
  }
  .data  : {
    *(.data)
  }
  .bss  :
  {
    *(.bss)
  }
}

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# Makefile for Kernel
CC:= C:\djgpp\bin\gcc       <- Aqui é definido o local onde está instalado o DJGPP
COBJS   := kernel.o video.c <- Para cada arquivo *.c criado para nosso OS
ASMOBJS:= k_entry.o         <- Para cada arquivo *.asm criado para nosso OS
OBJS:= $(COBJS) $(ASMOBJS)
CFILES  := $(COBJS:%.o=%.c)
ASMFILES:= $(ASMOBJS:%.o=%.asm)
ASM:=C:\djgpp\bin\nasm             <- Aqui é definido o local onde está instalado o NASM
LD := C:\djgpp\bin\ld      <- Aqui é definido o local onde está instalado o Link

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@echo off
del *.bin
C:\djgpp\bin\MAKE
PAUSE