[U-Boot] [PATCH 1/8] x86: Initialize GDT entry 1 to be the 32-bit CS as well

[Simon Glass]

On Thursday, 24 September 2015, Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Some OS (like VxWorks) requires GDT entry 1 to be the 32-bit CS.
>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
>
>  arch/x86/cpu/cpu.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
> index 1b76ca1..812c5e4 100644
> --- a/arch/x86/cpu/cpu.c
> +++ b/arch/x86/cpu/cpu.c
> @@ -142,7 +142,12 @@ void arch_setup_gd(gd_t *new_gd)
>
>         gdt_addr = new_gd->arch.gdt;
>
> -       /* CS: code, read/execute, 4 GB, base 0 */
> +       /*
> +        * CS: code, read/execute, 4 GB, base 0
> +        *
> +        * Some OS (like VxWorks) requires GDT entry 1 to be the 32-bit CS
> +        */
> +       gdt_addr[X86_GDT_ENTRY_UNUSED] = GDT_ENTRY(0xc09b, 0, 0xfffff);
>         gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
>
>         /* DS: data, read/write, 4 GB, base 0 */
> --
> 1.8.2.1
>

 Acked-by: Simon Glass <sjg at chromium.org>