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My Problem:
----------

I have these files

Kernel.c
--------

void print(char *text)
{
char *vidmem = (char *)0xB8000;

while(*text != 0)
{
  *vidmem = *text;
  vidmem++;
  *vidmem = 0x07;
  vidmem++;
  text++;
}

}

void Dmain()
{
print("Hello World !!!");
}


Start.asm
---------
extern _Dmain
global _main

[SEGMENT .text]
[BITS 32]

_main:
        call _Dmain
        mov ax,0x0
        ret
        hlt


link.ld
-------
SECTIONS
{
  .text 0x00100000 :
  {
   *(.text)
  }

}


---------------------

Now I created coff files from these files and they are kernel.o and start.o.

And then I linked them using ld using the following command

ld -T link.ld kernel.o start.o --oformat binary -o kernel.bin

Now when I try to load my kernel I get a triple fault exception (definitely not what I expected).

I don't know what's the problem - something tells me that the problem is in my linker script.

Can someone tell me how to get 16-bit output from gcc( I tried the asm(".code16gcc") - didn't work)

Please help me.


cheers

ksk

Hi,
1)
-        call _Dmain
-        mov ax,0x0
-        ret     // this may not be needed, it may coz reboot if u r in pmode
-        hlt

2) if u r losding the kernel after setting up the pmode, then u have to use the seg selector to write 2 the video memory, u shouldn't write like this.

   it doesn't matter if u r producing 16 or 32 bit code, better write ur own bootloader.

rgds,
YogaRamanan.T

I dont think you should have the
mov ax,0
ret
instead use
cli
hlt

and try using GRUB to boot the file

Dont forget the entry point in the linker script

After actually reading your code just put ENTRY(_main) in your linker script.
Also in your link.ld you should have this OUTPUT_FORMAT("binary")
so link.ld should look like this
OUTPUT_FORMAT("binary")
ENTRY(_main)

SECTIONS
{
  .text 0x00100000 :
  {
   *(.text)
  }

}
also your linking it wrong:
ld -T link.ld start.o kernel.o --oformat binary -o kernel.bin
that is the right way.

or if you want it all in one file you could do this

void Dmain(void)
{
        print("Hello, World\n");
        asm(
        "mov %ax,$0      \n"
        "cli \n"
        "hlt");
}
and in link.ld
ENTRY(_Dmain)
and you wouldnt need start.asm
I did it in my kernel and it works fine
Althought its just a suggestion.

Good Luck
--KERNEL PANIC--
SystemHalted