On 6 June 2015 at 21:33, Bin Meng <bmeng...@gmail.com> wrote: > Currently the FSP execution environment GDT is setup by U-Boot in > arch/x86/cpu/start16.S, which works pretty well. But if we try to > move the FspInitEntry call a little bit later to better fit into > U-Boot's initialization sequence, FSP will fail to bring up the AP > due to #GP fault as AP's GDT is duplicated from BSP whose GDT is > now moved into CAR, and unfortunately FSP calls AP initialization > after it disables the CAR. So basically the BSP's GDT still refers > to the one in the CAR, whose content is no longer available, so > when AP starts up and loads its segment register, it blows up. > > To resolve this, we load GDT before calling into FspInitEntry. > The GDT is the same one used in arch/x86/cpu/start16.S, which is > in the ROM and exists forever. > > Signed-off-by: Bin Meng <bmeng...@gmail.com> > Tested-by: Andrew Bradford <andrew.bradf...@kodakalaris.com> > Tested-by: Simon Glass <s...@chromium.org> > > --- > > Changes in v3: > - Rename gdt in arch/x86/cpu/start16.S to gdt_rom > - Change 'extern u32 gdt' to 'extern char gdt_rom[]' > - Add comments to setup_fsp_gdt()
Acked-by: Simon Glass <s...@chromium.org> _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
