Re: port-i386/52266: Double fault early in boot with AMD Am5x86 CPU

[Andreas Gustafsson <gson%gson.org@localhost>]

The following reply was made to PR port-i386/52266; it has been noted by GNATS.

From: Andreas Gustafsson <gson%gson.org@localhost>
To: Kimihiro Nonaka <nonakap%gmail.com@localhost>
Cc: "gnats-bugs\@netbsd.org" <gnats-bugs%netbsd.org@localhost>
Subject: Re: port-i386/52266: Double fault early in boot with AMD Am5x86 CPU
Date: Tue, 11 Jul 2017 16:31:20 +0300

 Kimihiro Nonaka wrote:
 > Could you try the following patch?
 > 
 > diff --git a/sys/arch/x86/x86/lapic.c b/sys/arch/x86/x86/lapic.c
 > index 415bb65b4e5..f87de042054 100644
 > --- a/sys/arch/x86/x86/lapic.c
 > +++ b/sys/arch/x86/x86/lapic.c
 > @@ -237,7 +237,8 @@ lapic_is_x2apic(void)
 >  {
 >      uint64_t msr;
 > 
 > -    if (rdmsr_safe(MSR_APICBASE, &msr) == EFAULT)
 > +    if (!ISSET(cpu_feature[0], CPUID_MSR) ||
 > +        rdmsr_safe(MSR_APICBASE, &msr) == EFAULT)
 >          return false;
 >      return (msr & (APICBASE_EN | APICBASE_EXTD)) ==
 >          (APICBASE_EN | APICBASE_EXTD);
 > 
 
 My Crusoe still reboots immediately after loading the kernel, even
 with the patch.
 -- 
 Andreas Gustafsson, gson%gson.org@localhost