Very Computer

I have some problems switching to protected mode.

This code is loaded at segment 0x1000 and starts execution at start

GDT:
        .word   0, 0, 0, 0

        .word   0xffff
        .word   0x0000    /* boot segment 0x1000 */
        .word   0x9a01
        .word   0x0040

        .word   0xffff
        .word   0x0000
        .word   0x9c01
        .word   0x0040

GDTR:
        .word   19, 0, 0

start:
        .byte   0x66
        mov     $GDT, %eax
        .byte   0x67             /* address prefix */
        .byte   0x66             /* data prefix */
        movl    %eax, GDTR + 2

        cli

        .byte   0x67, 0x66
        lgdt    GDTR

        mov     %cr0, %eax
        .byte   0x66
        or      $1, %eax
        mov     %eax, %cr0

        .byte   0x66
        ljmp    $0x08, $prot

prot:
        movw    $0x10, %ax
        mov     %ax, %ds
        mov     %ax, %ss
        mov     %ax, %es

This (nicely ?) reboots my machine.

What is wrong. Thank you for your help.

Nicolas

I thought Linux was ALWAYS in protected mode... I can't imagine a user
process being allowed to change that setting!  Are you writing a kernel
or something?

Good luck,
-BenRI

Quote:> What is wrong. Thank you for your help.

        Stefan "hope it helps"

My $0.0002

Martynas