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

On Thursday, 24 September 2015, Bin Meng bmeng.cn@gmail.com wrote:

Some OS (like VxWorks) requires GDT entry 1 to be the 32-bit CS.

Signed-off-by: Bin Meng bmeng.cn@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@chromium.org