On 2016-04-26, Theo de Raadt <dera...@cvs.openbsd.org> wrote:
>> int
>> selwd_probe(struct device *parent, void *match, void *aux)
>> {
>> struct isa_attach_args *ia = aux;
>> bus_space_tag_t iot;
>> bus_space_handle_t ioh;
>>
>> /* Match by device ID */
>> iot = ia->ia_iot;
>> if (bus_space_map(iot, ia->ipa_io[0].base, SELWD_IOSIZE, 0, &ioh))
>> return 0;
>
> ...
>
>> /* read model number */
>> char *model = malloc(sizeof(char)*16, M_DEVBUF, M_WAITOK | M_ZERO);
>> selwd_read_modelno(iot, ioh, model);
>
> This is worrying. It assumes that all systems have this hardware.
>
> And it starts by doing a "write".
Is there no WDRT or WDAT table in ACPI on this hardware? Most "modern"
(2006-on) watchdogs on PCs with ACPI support have the WDRT table described
in https://msdn.microsoft.com/en-us/windows/hardware/gg463320.aspx
Check for /tmp/acpi.WD[AR]T.* files after running acpidump -o /tmp/acpi ..
