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    SubjectRe: [i386] Questions regarding provisional page tables initialization
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    Hi Andreas,

    On Mon, Jul 02, 2007 at 11:18:08AM +0200, Andreas Schwab wrote:
    > "Ahmed S. Darwish" <darwish.07@gmail.com> writes:
    >
    > > yes, but isn't the displacement here (0x007) a _bytes_ displacement ?. so
    > > effectively, %ecx now contains physical address of pg0 + 7bytes. Is it A
    > > meaningful place/address ?.
    >
    > It's not pg0 + 7bytes, it is pg0 plus 3 flag bits. Since a page address
    > is always page aligned, the low bits are reused for flags.
    >

    I'm sure there's a problem in _my_ understanding, but isn't the displacement
    - as specified by AT&T syntax - represented in bytes ?. I've wrote a small
    assembly function to be sure:

    .data
    integer:
    .string "%d\n"

    .text
    test_func:
    push %ebp
    mov %esp, %ebp
    push 0x008(%ebp) ## 8 bytes displacement (the first arg), right ?
    push $integer
    call printf
    mov %ebp, %esp
    pop %ebp
    ret

    The above method works fine and prints "5" to stdout by the code:

    .global main
    main:
    mov $5, %eax
    push %eax
    call test_func

    movl $1, %eax
    movl $0, %ebx
    int $0x80

    now back to head.S code:
    leal 0x007(%edi),%ecx /* Create PDE entry */

    Isn't the above line the same condition (bytes, not bits displacement) ?.
    Thanks for your patience !.

    (For other kind replies, don't understand me wrong. I did my homework and
    studied the pte format before asking ;). It's just the bytes/bits issue
    above that confuses me).

    --
    Ahmed S. Darwish
    HomePage: http://darwish.07.googlepages.com
    Blog: http://darwish-07.blogspot.com
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