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

[Michael Gmelin]

> 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).

Best,
Michael