Fatal trap 12: page fault on Acer Chromebook 720 (peppy)

[Michael Gmelin]

> On 22. Aug 2018, at 17:46, Konstantin Belousov <kostikbel at gmail.com> wrote:
> 
>> On Tue, Aug 21, 2018 at 12:14:35AM +0200, Michael Gmelin wrote:
>> 
>> 
>>>> On 20. Aug 2018, at 17:09, Konstantin Belousov <kostikbel at gmail.com> wrote:
>>>> 
>>>> On Mon, Aug 20, 2018 at 12:45:12AM +0200, Michael Gmelin wrote:
>>>> 
>>>> See here for a screenshot (also including the output of "show pte
>>>> 0xfffff80001000000"):
>>>> 
>>>> https://gist.github.com/grembo/78d0f2a100dd4f16775b85a118769658#file-ddb1-png
>>> It is too early for ddb routines to register.
>>> Ok can you try the following debugging patch, to verify my guess ?
>>> 
>>> diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
>>> index 18777d23f09..cd05fdb763f 100644
>>> --- a/sys/amd64/amd64/pmap.c
>>> +++ b/sys/amd64/amd64/pmap.c
>>> @@ -1052,8 +1052,7 @@ create_pagetables(vm_paddr_t *firstaddr)
>>>       pd_p = (pd_entry_t *)DMPDkernphys;
>>>       for (i = 0; i < (NPDEPG * nkdmpde); i++)
>>>           pd_p[i] = (i << PDRSHIFT) | X86_PG_V | PG_PS | pg_g |
>>> -                X86_PG_M | X86_PG_A | pg_nx |
>>> -                bootaddr_rwx(i << PDRSHIFT);
>>> +                X86_PG_M | X86_PG_A | pg_nx | X86_PG_RW;
>>>       for (i = 0; i < nkdmpde; i++)
>>>           pdp_p[i] = (DMPDkernphys + ptoa(i)) | X86_PG_RW |
>>>               X86_PG_V;
>> 
>> With this change it boots okay (mptramp_pagetables is 0x1000000, as expected).
> 
> Can you apply the following on top of the previous debugging patch and show
> me the line printed ?
> 
> diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
> index 3d70532b7fd..613fa9f2165 100644
> --- a/sys/amd64/amd64/pmap.c
> +++ b/sys/amd64/amd64/pmap.c
> @@ -2662,6 +2662,7 @@ pmap_pinit0(pmap_t pmap)
>        pmap->pm_pcids[i].pm_gen = 1;
>    }
>    pmap_activate_boot(pmap);
> +printf("bootaddr addr %#lx rwx %#lx btext %#lx _end %#lx brwsection %#lx etext %#lx KERNBASE %#lx\n", 0x1000000UL, bootaddr_rwx(0x1000000UL), (uintptr_t)btext, (uintptr_t)_end, (uintptr_t)brwsection, (uintptr_t)etext, (uintptr_t)KERNBASE);
> }
> 
> void

bootaddr addr 0x1000000 rwx 0 btext 0xffffffff80342000 _end 0xffffffff823cf840 brwsection #ffffffff81a00000 etext 0xffffffff812041e4 KERNBASE 0xffffffff80000000

Best,
Michael