Question about u-boot on the i.MX6q SABRE SD platform

[frank_zhang]

Hi,all,

We bought an i.MX6q SABRE SD platform, and Android operation system was pre-installed in the SD card. Now we want to install an Ubuntu Linux operation system in the SD card, we followed the instruction on u-boot on the i.MX6 sabre sd platform in a few commands. Unfortunately, we failed when boot the SD card.

The SD card was property partitioned like:

fdisk -l /dev/sdb

Disk /dev/sdb: 7948 MB, 7948206080 bytes

255 heads, 63 sectors/track, 966 cylinders, total 15523840 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1            2048    15518789     7758371    b  W95 FAT32

Then we run the commands:

$ dd if=u-boot.imx of=/dev/sdb bs=1k seek=1

$ sync

with no warnings and errors reported.

But we are confused about why the u-boot.imx can not be seen in the SD card. Insert the SD card into the SD card slot of i.MX6 sabre sd platform, and connect to the USB to UART port with a serial terminal, we got the u-boot messages:

U-Boot 2014.07-rc3-00068-gd8a97f9 (Jun 13 2014 - 20:03:10)

CPU:   Freescale i.MX6Q rev1.2 at 792 MHz

Reset cause: POR

Board: MX6-SabreSD

DRAM:  1 GiB

MMC:   FSL_SDHC: 0, FSL_SDHC: 1, FSL_SDHC: 2

*** Warning - bad CRC, using default environment

No panel detected: default to Hannstar-XGA

Display: Hannstar-XGA (1024x768)

In:    serial

Out:   serial

Err:   serial

Net:   FEC [PRIME]

Hit any key to stop autoboot:  0

switch to partitions #0, OK

mmc1 is current device

reading boot.scr

** Unable to read file boot.scr **

reading zImage

** Unable to read file zImage **

Booting from net ...

FEC Waiting for PHY auto negotiation to complete......... TIMEOUT !

BOOTP broadcast 1

BOOTP broadcast 2

BOOTP broadcast 3

BOOTP broadcast 4

BOOTP broadcast 5

Can you find any mistakes in these operations? Should the SW6-Boot Mode Selector Switch be pre-configured that the U-boot in SD card, not the U-boot in onboard Flash(If it has) take effect?

Best Regards!

Yao

[yahuicao]

Hi, Yao:

       BOOT SD Card from Slot3(J507) :

       Switch   D1     D2       D3         D4      D5        D6       D7      D8

       SW6   OFF     ON     OFF     OFF     OFF     OFF     ON     OFF                  

The operations above you've made is correct, but there is more to be done to boot a Ubuntu Linux.

You are confused about why the u-boot.imx can not be seen in the SD card?

Because the u-boot.imx is written to the SD Card starting from the address of 1KB, which doesn't locate in the first partition. The first 1 KB of the SD/MMC card, that includes the partition table, will be preserved. Actually, the bootloader inside the i.MX6Q just read the RAW data starting from the address of 1KB of the SD Card.

After you dd the u-boot.imx into the SD Card, you boot it successfully:

……………………

** Unable to read file boot.scr **

reading zImage

** Unable to read file zImage **

Booting from net ...

But the u-boot can't find the linux kernel:

from the print log above, you can see that u-boot find the boot.scr first,, if failed,then read the zImage(which is the kernel) and if failed again, it boot from the net(download zImage from the tftp server).

So there is more to be done and I think you'd better refer to the i.MX 6Dual/6Quad SABRE-SD Linux User's Guide for more detail. And finally you'll make it!

https://www.freescale.com/webapp/Download?colCode=L3.0.35_4.1.0_LINUX_DOCS&location=null&fsrch=1&sr=...

[Meihui_Cao]

Hi,

Today we have installed a Ubuntu 12.04 Linux operate system successfully. But the LVDS display and spesker board doesn't work. During the boot process, it displayed as follows:

* Starting load fallback graphics devices

[fail]

Does it means that it doesn't have the graphics driver? How can we update the graphics driver?

Look forward to your reply.

Meihui Cao.

[yahuicao]

Well, the log shows that the driver didn't work. I suggest that you download the pre-compiled Ubuntu Image released from the Freescale website. This works OK for all Freescale boards.

link: i.MX 6Quad, i.MX 6Dual, i.MX 6DualLite, i.MX 6Solo and i.MX 6Sololite Linux File System for the Ubun...

And I think you'd better check the Freescale website(both software & documentation) for more details.

link: IMX6_SW: i.MX 6 Series Software and Development Tool Resources

[Meihui_Cao]

Hi,

Thank you very much for your reply. Now we have install a Ubuntu Linux operate system successfully. It shows 12.04 LTS is available, but when we use 'do-release-ungrade' to upgrade to 12.04 , we failed. And then we followed the instruction on Linaro Releases to install a 12.04 ubuntu, we failed.

How can we get a 12.04 Ubuntu Linux operation system?

    What's more, we followed the instruction ’i.MX_6Dual6Quad_SABRE-SD_Linux_Users_Guide.pdf‘ to boot up the system through rootfs in SD card through HannStar LVDS:

### For LVDS0 connection

MX6Q SABRESD U-Boot > setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/

mmcblk1p1 rootwait rw video=mxcfb0:dev=ldb,LDB-XGA,if=RGB666'

### For LVDS1 connection

MX6Q SABRESD U-Boot > setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/

mmcblk1p1 rootwait rw video=mxcfb0:dev=ldb,LDB-XGA,if=RGB666 ldb=sin1'

MX6Q SABRESD U-Boot >setenv bootcmd_mmc 'run bootargs_base bootargs_mmc;mmc dev 2;mmc

read ${loadaddr} 0x800 0x2000;bootm'

MX6Q SABRESD U-Boot > setenv bootcmd 'run bootcmd_mmc'

MX6Q SABRESD U-Boot > saveenv

Then we failed. How can we make the LVDS display and spesker board work?

[wallyyeh]

Hi, Yao:

    yes, SW6-Boot Mode need select to SD card(and in the Sabre-SD, there are slot 2 and 3 you need insert it in the correct slot) first. but through your log, these was one line:

"mmc1 is current device", so I guess you're already using the u-boot from your SD card?

    From log, your u-boot doesn't contain a correct u-boot environment to load kernel and trying to get it from net. maybe should using:

"print bootcmd" to see what is the boot command now.

[Meihui_Cao]

Hi,

Today we have installed a Ubuntu 12.04 Linux operate system successfully. But the LVDS display and spesker board doesn't work. During the boot process, it displayed as follows:

* Starting load fallback graphics devices

[fail]

Does it means that it doesn't have the graphics driver? How can we update the graphics driver?

Look forward to your reply.

Meihui Cao.