Re: [PATCH v2 3/4 RESEND] MIPS: Loongson64: Add /proc/boardinfo

[Tiezhu Yang]

On 10/13/2020 08:15 AM, Jiaxun Yang wrote:
> 于 2020年10月12日 GMT+08:00 下午8:02:25, Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> 写到:
> > On 10/12/2020 06:38 PM, Thomas Bogendoerfer wrote:
> > > On Sun, Oct 11, 2020 at 07:47:53AM +0800, Tiezhu Yang wrote:
> > > > Add /proc/boardinfo to get mainboard and BIOS info easily on the Loongson
> > > > platform, this is useful to point out the current used mainboard type and
> > > > BIOS version when there exists problems related with hardware or firmware.
> > > >
> > > > E.g. with this patch:
> > > >
> > > > [loongson@linux ~]$ cat /proc/boardinfo
> > > > Board Info
> > > > Manufacturer            : LEMOTE
> > > > Board Name              : LEMOTE-LS3A4000-7A1000-1w-V01-pc
> > > > Family                  : LOONGSON3
> > > >
> > > > BIOS Info
> > > > Vendor                  : Kunlun
> > > > Version                 : Kunlun-A1901-V4.1.3-20200414093938
> > > > ROM Size                : 4 KB
> > > > Release Date            : 2020-04-14
> > > Why does Loongson64 need this extra file no other architecture or MIPS
> > > platform need ? Do others provide this information via a different method ?
> > > If yes, why can't Loongson64 do the same ?
> > Hi Thomas,
> >
> > This is related with the implementation of firmware.
> >
> > Using dmidecode command can get the similar info if there exists SMBIOS
> > in firmware, but the fact is there is no SMBIOS on some machines, we can
> > see nothing when execute dmidecode, like this:
> >
> > [root@linux loongson]# dmidecode
> > # dmidecode 2.12
> > # No SMBIOS nor DMI entry point found, sorry.
> >
> > The following three structures are already defined in the interface
> > specification about firmware and kernel on the Loongson platform,
> > this is common requirement and specific for Loongson64, so add a
> > new boardinfo.c file in arch/mips/loongson64.
> >
> > arch/mips/include/asm/mach-loongson64/boot_param.h
> > struct interface_info {
> >      u16 vers; /* version of the specificition */
> >      u16 size;
> >      u8  flag;
> >      char description[64];
> > } __packed;
> >
> > struct board_devices {
> >      char name[64];    /* hold the device name */
> >      u32 num_resources; /* number of device_resource */
> >      /* for each device's resource */
> >      struct resource_loongson resource[MAX_RESOURCE_NUMBER];
> >      /* arch specific additions */
> >      struct archdev_data archdata;
> > };
> >
> > struct loongson_special_attribute {
> >      u16 vers;     /* version of this special */
> >      char special_name[64]; /* special_atribute_name */
> >      u32 loongson_special_type; /* type of special device */
> >      /* for each device's resource */
> >      struct resource_loongson resource[MAX_RESOURCE_NUMBER];
> > };
> Hi Tiezhu,
>
> Through I don't think touching top level of proc would be a good idea. It's all about API consistency.
>
> If you intend to provide user an interface then I guess /sys/firmware/lefi
> like what DMI did or somewhere less critical is better.
>
> There is no guarantee that Loongson64 device would come with LEFI,
> although it's mandatory for now.

Hi Jiaxun,

Thank you very much.

Let us add /sys/firmware/lefi/boardinfo, I will do it and then send a 
new patch.

Thanks,
Tiezhu

> Thanks.
>
> - Jiaxun
>
> > Thanks,
> > Tiezhu
> >
> > > Thomas.