[PATCH 3/5] x86: cpu: Skip init code when chain loading

[Simon Glass]

Hi Bin,

On Mon, 3 Feb 2020 at 04:11, Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Hi Simon,
>
> On Sun, Dec 22, 2019 at 12:13 AM Simon Glass <sjg at chromium.org> wrote:
> >
> > When U-Boot is not the first-stage bootloader the interrupt and cache init
> > must be skipped, as well as init for various peripherals. Update the code
> > to add checks for this.
> >
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> > ---
> >
> >  arch/x86/cpu/cpu.c            | 4 +++-
> >  arch/x86/cpu/i386/interrupt.c | 3 +++
> >  arch/x86/lib/init_helpers.c   | 3 +++
> >  3 files changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
> > index d626e38fd1..d82305303a 100644
> > --- a/arch/x86/cpu/cpu.c
> > +++ b/arch/x86/cpu/cpu.c
> > @@ -238,8 +238,10 @@ int cpu_init_r(void)
> >         struct udevice *dev;
> >         int ret;
> >
> > -       if (!ll_boot_init())
> > +       if (!ll_boot_init()) {
> > +               uclass_first_device(UCLASS_PCI, &dev);
> >                 return 0;
> > +       }
> >
> >         ret = x86_init_cpus();
> >         if (ret)
> > diff --git a/arch/x86/cpu/i386/interrupt.c b/arch/x86/cpu/i386/interrupt.c
> > index 78aa51a3ea..c33ca165d8 100644
> > --- a/arch/x86/cpu/i386/interrupt.c
> > +++ b/arch/x86/cpu/i386/interrupt.c
> > @@ -261,6 +261,9 @@ int interrupt_init(void)
> >         struct udevice *dev;
> >         int ret;
> >
> > +       if (!ll_boot_init())
> > +               return 0;
> > +
>
> If you scroll down a little bit in this function, you see there is
> already a ll_boot_init() check. We need some consolidation here.
>
> >         /* Try to set up the interrupt router, but don't require one */
> >         ret = uclass_first_device_err(UCLASS_IRQ, &dev);
> >         if (ret && ret != -ENODEV)
> > diff --git a/arch/x86/lib/init_helpers.c b/arch/x86/lib/init_helpers.c
> > index 5bb55e256f..d906b528b3 100644
> > --- a/arch/x86/lib/init_helpers.c
> > +++ b/arch/x86/lib/init_helpers.c
> > @@ -30,6 +30,9 @@ int init_cache_f_r(void)
> >                         return ret;
> >         }
> >
> > +       if (!ll_boot_init())
> > +               return 0;
>
> I am not convinced that we should add the ll_boot_init() check here.
> This function already has a do_mtrr variable that is based on the
> config options.

Yes but as per my other explanation, we are not using those config
options. The idea is to boot an image as close as possible to the
bare-metal one.

Regards,
Simon