Re: [SeaBIOS] Does SeaBIOS support eMMC?

[Kevin O'Connor]

On Mon, Jan 11, 2016 at 03:49:19PM +0000, Scheithauer, Mario wrote:
> First I will clone a new coreboot with an actual SeaBIOS. After that
> I will give you a new log.
> But second I think sdcard setup is not ready for JEDEC Standard
> 84-B51. Maybe I'm wrong with that.

I did use that JEDEC standard as a reference when writing the code.
> Our eMMC flash has a size of 8GB but recognized are only 2GB and I
> believe for switching to high-speed mode there are some more steps
> necessary.

SeaBIOS does not attempt to enable high speed mode or to enable
multiple read data lines.  The goal is just to boot the OS - the OS
can then enable whatever optimizations it wants.

The drive is showing up as an 2TB drive, so something is clearly wrong
with the size detection.  Upon attempting to boot from the drive, a
read CRC error occurs.  I wonder if the drive is not in sync with the
controller on the number of data lines in use.

How many SD/MMC devices are in this machine?  In addition to the eMMC
drive that is detected, another device starts the detection on a
different controller but fails earlier in the process.  Is that
expected?

-Kevin

Does SeaBIOS support eMMC?

[Scheithauer, Mario]

Hi Kevin,
> -----Ursprüngliche Nachricht-----
> Von: Kevin O'Connor [mailto:[e-mail]]
> Gesendet: Dienstag, 12. Januar 2016 17:15
> An: Scheithauer, Mario
> Cc: [e-mail]
> Betreff: Re: [SeaBIOS] Does SeaBIOS support eMMC?
>
> On Mon, Jan 11, 2016 at 03:49:19PM +0000, Scheithauer, Mario wrote:
> > First I will clone a new coreboot with an actual SeaBIOS. After that I
> > will give you a new log.
> > But second I think sdcard setup is not ready for JEDEC Standard
> > 84-B51. Maybe I'm wrong with that.
>
> I did use that JEDEC standard as a reference when writing the code.
> > Our eMMC flash has a size of 8GB but recognized are only 2GB and I
> > believe for switching to high-speed mode there are some more steps
> > necessary.
>
> SeaBIOS does not attempt to enable high speed mode or to enable multiple read
> data lines.  The goal is just to boot the OS - the OS can then enable whatever
> optimizations it wants.

Well, I understand.
> The drive is showing up as an 2TB drive, so something is clearly wrong with the
> size detection.  Upon attempting to boot from the drive, a read CRC error occurs.
> I wonder if the drive is not in sync with the controller on the number of data lines in
> use.

I believe the mechanism to determine the size for eMMC4.5 devices are differently than up to now.
However, that is no problem.
> How many SD/MMC devices are in this machine?  In addition to the eMMC drive
> that is detected, another device starts the detection on a different controller but
> fails earlier in the process.  Is that expected?

We have two Storage Control Cluster, one for SDIO / SD and one for eMMC 4.5.
In my opinion a device should be only at the second SCC connected.
However, should the last version of Lubuntu not work with that?
Lubuntu detects an mmc block device (mmcblk0boot0 and mmcblk0boot1).
But the size is not correct. Both blocks have a size of 256kB.
Fdisk cannot install a partition and ends with the error message 'failed to write disklabel: Operation not permitted'.
Maybe we have a hardware issue, because the eMMC device is directly on the board.
Hm, but the first steps to initialize the device do not look at all so bad.
So, it's enough for today.
Bye!
> -Kevin