[U-Boot] [PATCH v2 1/2] x86: Add efi runtime reset

[Simon Glass]

Hi Alex,

On Mon, 28 Jan 2019 at 12:15, Alexander Graf <agraf at suse.de> wrote:
>
>
>
> On 28.01.19 20:13, Simon Glass wrote:
> > Hi,
> >
> > On Mon, 28 Jan 2019 at 08:42, Alexander Graf <agraf at suse.de> wrote:
> >>
> >> Our selftest will soon test the actual runtime reset function rather than
> >> the boot time one. For this, we need to ensure that the runtime version
> >> actually succeeds on x86 to keep our travis tests work.
> >>
> >> So this patch implements an x86 runtime reset function. It is missing
> >> shutdown functionality today, but OSs usually implement that via ACPI
> >> and this function does more than the stub from before, so it's at least
> >> an improvement.
> >>
> >> Signed-off-by: Alexander Graf <agraf at suse.de>
> >> ---
> >>  drivers/sysreset/sysreset_x86.c | 23 +++++++++++++++++++++++
> >>  1 file changed, 23 insertions(+)
> >>
> >> diff --git a/drivers/sysreset/sysreset_x86.c b/drivers/sysreset/sysreset_x86.c
> >> index 20b958cfd4..efed45ccb7 100644
> >> --- a/drivers/sysreset/sysreset_x86.c
> >> +++ b/drivers/sysreset/sysreset_x86.c
> >> @@ -10,6 +10,29 @@
> >>  #include <sysreset.h>
> >>  #include <asm/io.h>
> >>  #include <asm/processor.h>
> >> +#include <efi_loader.h>
> >> +
> >> +#ifdef CONFIG_EFI_LOADER
> >> +void __efi_runtime EFIAPI efi_reset_system(
> >> +                       enum efi_reset_type reset_type,
> >> +                       efi_status_t reset_status,
> >> +                       unsigned long data_size, void *reset_data)
> >> +{
> >> +       u32 value = 0;
> >> +
> >> +       if (reset_type == EFI_RESET_COLD)
> >> +               value = SYS_RST | RST_CPU | FULL_RST;
> >> +       else if (reset_type == EFI_RESET_WARM)
> >> +               value = SYS_RST | RST_CPU;
> >
> > The EFI should use the sysreset driver and sysreset_walk() or similar,
> > rather than having a function called directly.
>
> It can't. At this point all of DM is long gone. We're in runtime space here.

This has come up before. We'll end up with a lot of duplication if we
cannot solve this. I think the run-time code will need to be built and
linked separately so that all necessary code is pulled in.

Regards,
Simon