There are a number of issues here:

1) The microcode that is being included is not a part of coreboot, so it needs to be disabled for the default build so that abuild doesn't fail. Intel wants to release the microcode as part of the FSP package and not include it in the coreboot repo so that the microcode vs FSP versions can be matched up.

2) The microcode that's included for the intel FSP is for B2/B3 silicon, but it seems like many users are still using B0 silicon, which requires a different microcode patch. This shouldn't be a problem but since there are 4 SKUs of Bay Trail and using the microcode for the wrong SKU will *APPEAR* to work, but cause issues later, the microcode can cause massive amounts of confusion.

3) The way that the microcode is currently being included is (to my understanding) completely against the Intel licensing. We're compiling a .h file with a license that says that it *CANNOT* be made GPL into a file with a GPL header. As far as I understand, this is a "Bad Thing". I think that this goes for ALL of the Intel platforms in coreboot currently. If you look at the license from the Intel download site where the microcode that is currently checked into the coreboot tree comes from, I'm not convinced that what we're doing is really okay. I could be wrong, but my current thinking is that it really shouldn't be handled the way we're doing it. I've been working on turning the microcode into binary blobs that can be included without compiling and linking against the GPL code, but I don't have anything ready to submit yet.

4) The FSP is supposed to give a warning at boot time if the microcode doesn't load correctly, but I'm speculating that it may be accessing an MSR that is not legal if the microcode isn't loaded and is hanging instead. This prevents coreboot from notifying the user with a post code that the microcode wasn't loaded and just leaves a 0x0000 on the post code display. Because this is done before there's any serial output, the user has no way of knowing what the problem is.

5) The (b3) microcode should be included automatically already if the mainboard "Configure defaults for the Intel FSP package" option is selected. I'm trying to figure out why the Kconfig select statements in the bayleybay_fsp directory aren't enabling the correct options. As I said in my last note, the code is there to enable everything, and it works if nothing is selected, but once the selections are made, they don't change automatically the way I had intended. I'm still looking at this, but so far I haven't gotten it to work as I wanted. I may have to go back and re-write some of the other options to be selected by a default setting and then use the select to set the default. I'm not sure yet.

Martin


On 06/04/2014 12:59 PM, WANG FEI wrote:
I thought microcode files are kind of patches for CPU, it suppose to be loaded before MRC just in case it fixes any issues related with CPU. I actually did encounter an system random halt issue related with no loading microcode before MRC training.

Martin, how do you think to display a warning during coreboot compiling if PLATFORM_USES_FSP selected but microcode does not configure properly.


On Wed, Jun 4, 2014 at 5:43 PM, Martin Roth <[email protected] <mailto:[email protected]>> wrote:

    Thanks Paul.

    I'm working on a fix for this. Right now the option get selected
    correctly if you set it at the first menuconfig run. If you go
    back and select the microcode options later, they don't get
    correctly enabled even though they're turned on with a select
    statement.

    I hope to have a patch up for this today.

    Martin




    On 06/03/2014 04:17 PM, Paul Menzel wrote:

        Dear Gerald,


        Am Dienstag, den 03.06.2014, 14:03 +0200 schrieb Gerald Otter:

            I am trying to run coreboot + seabios payload on the
            bayley bay crb
            with the recently committed FSP integration, but have had
            no luck so
            far.
            This crb uses the bay trail I (now atom e3800) soc from intel.

            Following the instructions from commit d75800c7f , I have
            built a 2MB
            image and flashed it to the upper 2MB of the 8MB flash,
            leaving the
            TXE / flash descriptor intact.
            I have added the config from the build. The FSP I used is
            BAYTRAIL_FSP_GOLD_002_10-JANUARY-2014, together with the flash
            descriptor and TXE from the 80.21 bios provided by intel,
            and vga bios
            36.2.2.
            Fwiw, I have tried both the 32bit and 64bit releases of
            the bios, even
            though the flash descriptor and TXE binary seem to be
            exactly the
            same.

            The issue I’m running into is that I have no idea if
            anything is
            running at all.
            There is no output on the VGA/HDMI ports or uart.

            The legacy uart referred to in the source is working
            correctly with
            the original intel bios, but does not produce any output
            with the
            coreboot image.
            I have tried the most common baud rates (115200, 19200,
            9600 ) and did
            some measurements with a scope in case I got the baud rate
            wrong, but
            no cigar.
            The uart I’m using is the PCU uart, as opposed to
            hsuart1/2 and the
            superIO uart. This matches with the configuration in
            coreboot when
            compared to the datasheet, so I’m assuming I got this set up
            correctly.
            Unfortunately, this is about all the information I have,
            so I hope I
            am missing something obvious when building the image /
            flashing it,
            etc.

        […]

        it looks like you are missing the microcode. (Next time please
        also send
        the output of `build/cbfstool build/coreboot.rom print`.)

        Could you please test if selecting “Generate from tree” in the
        prompt
        “Include CPU microcode in CBFS”?

        In the `.config`, instead of

                 # CONFIG_CPU_MICROCODE_CBFS_GENERATE is not set
                 # CONFIG_CPU_MICROCODE_CBFS_EXTERNAL is not set
                 CONFIG_CPU_MICROCODE_CBFS_NONE=y

        you should have the one below.

                 CONFIG_CPU_MICROCODE_CBFS_GENERATE=y
                 # CONFIG_CPU_MICROCODE_CBFS_EXTERNAL is not set
                 # CONFIG_CPU_MICROCODE_CBFS_NONE is not set


        Thanks,

        Paul




-- coreboot mailing list: [email protected]
    <mailto:[email protected]>
    http://www.coreboot.org/mailman/listinfo/coreboot




--
coreboot mailing list: [email protected]
http://www.coreboot.org/mailman/listinfo/coreboot

Reply via email to