Re: [coreboot] Minnowboard

[Zoran Stojsavljevic]

> First thing is to make sure the microcode is right without that it will hang before giving any output.

IIRC, there are two types of BYT-i used for IOTG, in INTEL. The CPUIDs
are 0x30673 (for Revision B) and 0x30679 (for Revision D). You can
retrieve CPUID using simplistic CLI: dmesg | grep microcode after
bringing Linux up:

[vuser@localhost ~]$ dmesg | grep microcode
[    0.000000] Intel Spectre v2 broken microcode detected; disabling
Speculation Control
[    3.796088] microcode: sig=0x40651, pf=0x40, revision=0x21
[    3.796202] microcode: Microcode Update Driver: v2.2.
[vuser@localhost ~]$

Daniel,

I suggest to you to put/flash original BYT-I BIOS back and read from
CMOS the CPUID and MCU numbers. Then you'll know exactly what
ingredients you'll need for Coreboot.

Here are some MCU numbers for BYT-I CPUIDs: 0x30673 (Rev. B) and
0x30679 (Rev. D):
https://lists.denx.de/pipermail/u-boot/2016-May/255536.html

Best Regards,
Zoran
_______

On Thu, Mar 22, 2018 at 6:47 PM, Michael Graichen
 wrote:
> Hey Daniel,
>
> What type of Minnowboard do you use?
>
> First thing is to make sure the microcode is right without that it will hang
> before giving any output.
>
> Best regards
> Michael
>
> -------- Ursprüngliche Nachricht --------
> Von: Zoran Stojsavljevic 
> Datum: 21.03.18 13:23 (GMT+01:00)
> An: Daniel Wagner 
> Cc: coreboot 
> Betreff: Re: [coreboot] Minnowboard
>
> Hello Daniel,
>
> You need to properly build Coreboot, integrating BYT-I (as I recall
> minnow board) FSP, and the info about BYT-I FSP you can find here:
> https://github.com/IntelFsp/FSP
>
> Zoran
> _______
>
> On Wed, Mar 21, 2018 at 12:47 PM, Daniel Wagner  wrote:
> > Hi,
> >
> > I would like to test my -rt kernels releases on the minnowboard. Though
> > cyclictest always reports 2 to 4 ms spikes. It looks like that the
> > original firmware is stealing those cycles. So my plan was to try out
> > coreboot and see if my theory is correct or not.
> >
> > Now, I am struggling with getting anything working. All my attempts to
> > bake a working binary have been completely fruitless. Not a single char
> > on the serial port. If I would at least get something on the serial port
> > I could find my way through the maze.
> >
> > I am confident that flashing the device is works correctly via my
> > raspberry pi [2]. When I flash the original firmware, the device comes
> > back to live again.
> >
> > Unfortunately, the documentation on how to configure and build coreboot
> > a bit outdated [1]. My google-foo didn't help either.
> >
> > Could someone share his/her current config and also post the SHAs of
> > coreboot? This would rule out that part. I am not sure if my binary
> > blobs I extracted or downloaded are okay (fd, me, gbe, FSB).
> >
> > Thanks,
> > Daniel
> >
> > [1] https://elinux.org/Minnowboard:MinnowMaxCoreboot
> > [2]
> >
> > https://3mdeb.com/firmware/flashing-minnowboard-turbot-with-raspberry-pi-zer...