OSDev.org

I am recently trying to wrote a simple kernel in pmode. The sequence goes like:
1) A boot loader loads a pure binary file into memory location 0x1000. And passes the control to this file.
2) This binary file loads simple kernel file into memory, enters pmode, and passes control to kernel. The assembly kernel stub of kernel is:

[bits 32]

[EXTERN _kernel_main]
[GLOBAL start]
[GLOBAL _sayhello]

start:
   mov ax,SYS_DATA_SEL_KERNEL
   mov ds,ax      ; not segments anymore: SELECTORS
   mov ss,ax
   nop
   mov es,ax
   mov fs,ax
   mov ax,LINEAR_SEL
   mov gs,ax

   jmp SYS_CODE_SEL_KERNEL:jumpEmpty
   jumpEmpty:

jmp $ ; halt


_sayhello:
   mov ax,LINEAR_SEL
   mov gs,ax


   mov byte [gs:0xB8000],'H'
   mov byte [gs:0xB8001],07h

   mov byte [gs:0xB8002],'E'
   mov byte [gs:0xB8003],07h

   mov byte [gs:0xB8004],'L'
   mov byte [gs:0xB8005],07h

   mov byte [gs:0xB8006],'L'
   mov byte [gs:0xB8007],07h

   mov byte [gs:0xB8008],'O'
   mov byte [gs:0xB8009],07h
ret

In that code,
jmp SYS_CODE_SEL_KERNEL:jumpEmpty
   jumpEmpty:

makes the cpu triple faulted.???. Any ideas about where the problem can be? The gdt is loaded by file loaded into 0x1000. It is copy-pasted into this kernel stub but I did not include it here. Also I checked that the problem was not about the value of SYS_CODE_SEL_KERNEL. I mean it has the value that it should have: It contains the selector which points to segment of the kernel. 10x...

I had forgot to say that the kernel is loaded into 0x5000... Also forgive me about bad English... ;D

Try:

Thanx for answer, It worked and I have found the problem...