How to build Linux 3.10.17 for iMX6?

[jasonjiang]

Hi,

There should be three things I need to build: rootfs, kernel, and uboot.

I downloaded kernel from here: linux-2.6-imx.git - Freescale i.MX Linux Tree, and uboot from here: uboot-imx.git - Freescale i.MX u-boot Tree. But I couldn't find where to download rootfs. Could somebody help?

With the cross-compiler installed previously, I built kernel by doing this under the root folder:

1. exportPATH=/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/:$PATH
2. export ARCH=arm
3. export CROSS_COMPILE=arm-none-linux-gnueabi-
4. make imx_v7_defconfig
5. sudo apt-get install lzop (need to install zlop)
6. make uImage LOADADDR=0x70008000 (need to specify load address to avoid build error)

The output file uImage was put under ./arch/arm/boot.

I then tried to build uboot. The first three steps are the same as above. But at step 4, I couldn't find a config file in the whole uboot tree. Can somebody tell me how to build?

I used this as reference: Linux booting on IMX6 SABRESDB. I tried to follow Ed's notes, but when building uboot, I also couldn't find the config file.

Thanks a lot.

Jason

[fabio_estevam]

- For U-boot

make mrproper

make mx6qsabresd_config

make

Then flash it into the SD card: dd if=u-boot.imx of=/dev/mmcblk0 bs=512 seek=2; sync

- For kernel

make imx_v7_defconfig

make -j4 uImage LOADADDR=0x10008000

make imx6q-sabresd.dtb

(Your LOADADDR was incorrect).

- For rootfs

You can use your favourite rootfs (Yocto, LTIB, buldroot, etc). Yocto does all the above steps for you and generate you a sdcard image ready to boot.

Regards,

Fabio Estevam

[jasonjiang]

Fabio,

Thanks to your reply, I was able to build u-boot.

I chose buildroot to build rootfs. I got the latest one from http://www.buildroot.org/download.html. I tried to build it in the following way:

$ make menuconfig...

#  Target ARM (Little-Endian)

#  Target Cortex A-9

#  Under toolchain:

#      External

#      Sourcery Codebench ARM 2013.05

#      Downloaded and installed

#  Under System Configuration, chose ttymxc0 as the Port to run a getty (login prompt) on,

#  Under Target Packages->Filesystem and Flash utilities: enable dosfstools and e2fsprogs

#  Under Filesystem Images, selected Output cpio - gzipped; tar the root filesystem

$ make busybox-menuconfig...

#  Do nothing, just exit (this step probably isn't necessary).

$ make V=1 2>&1 | tee make.out

But at the end, I got link error: "/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/../lib/gcc/arm-fsl-linux-gnueabi/4.6.2/../../../../arm-fsl-linux-gnueabi/bin/ld: cannot find crti.o: No such file or directory". I googled around for the whole day and just couldn't figure out the solution. Could you help please?

Thank you so much!

Jason

[jasonjiang]

Hi Fabio,

To this point, I was able to build u-boot and kernel successfully. But after I flashed them to SD card, it won't boot (cannot even see u-boot prompt). I replaced u-boot on the SD card with the one I always used (3.0.35), then I could see u-boot prompt. But when it tried to load kernel from SD card, it failed on CRC check as below.

MX6Q SABRESD U-Boot > boot

mmc2 is current device

MMC read: dev # 2, block # 2048, count 8192 ... 8192 blocks read: OK

## Booting kernel from Legacy Image at 10800000 ...

   Image Name:   Linux-3.10.17

   Image Type:   ARM Linux Kernel Image (uncompressed)

   Data Size:    5201152 Bytes =  5 MB

   Load Address: 10008000

   Entry Point:  10008000

   Verifying Checksum ... Bad Data CRC

ERROR: can't get kernel image!

BTW, I used the following commands to program u-boot and kernel onto SD card:

      sudo dd if=u-boot-mx6q-sabresd.bin of=/dev/sde bs=512 seek=2 skip=2 conv=fsync

      sudo dd if=uImage of=/dev/sde bs=512 seek=2048 conv=fsync

Do you have any idea what's going on?

Thank you very much.

Jason

[fabio_estevam]

Recent U-boot versions are flashed like this:

dd if=u-boot.imx of=/dev/mmcblk0 bs=512 seek=2; sync

Regards,

Fabio Estevam

[jasonjiang]

Great. I used your command to flash U-boot and it can boot to the prompt now. Sorry I missed your first note about this command.

I then flashed the kernel to the card using the command "dd if=uImage of=/dev/sde bs=512 seek=2048; sync". I tweaked the boot env a little (attached at the end), but still got the same error.

U-Boot > boot

mmc1 is current device

MMC read: dev # 1, block # 2048, count 8192 ... 8192 blocks read: OK

## Booting kernel from Legacy Image at 12000000 ...

   Image Name:   Linux-3.10.17

   Image Type:   ARM Linux Kernel Image (uncompressed)

   Data Size:    5201152 Bytes = 5 MiB

   Load Address: 10008000

   Entry Point:  10008000

   Verifying Checksum ... Bad Data CRC

ERROR: can't get kernel image!

U-Boot >

The boot envs are:

U-Boot > printenv

baudrate=115200

boot_fdt=try

bootargs=console=ttymxc0,115200 root=/dev/mmcblk1p1 rootwait

bootargs_base=setenv bootargs console=ttymxc0,115200

bootargs_mmc=setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootwait

bootcmd=run bootcmd_mmc

bootcmd_mfg=run mfgtool_args;bootm ${loadaddr} ${initrd_addr} ${fdt_addr};

bootcmd_mmc=run bootargs_base bootargs_mmc; mmc dev 1; mmc read ${loadaddr} 0x800 0x2000; bootm

bootdelay=1

bootfile=imx6q-sabresd.dtb

bootscript=echo Running bootscript from mmc ...; source

console=ttymxc0

ethact=FEC

ethaddr=00:04:9f:02:6e:c4

ethprime=FEC

fdt_addr=0x18000000

fdt_file=imx6q-sabresd.dtb

fdt_high=0xffffffff

get_cmd=dhcp

initrd_addr=0x12C00000

initrd_high=0xffffffff

ip_dyn=yes

loadaddr=0x12000000

loadbootscript=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};

loadfdt=fatload mmc ${mmcdev}:${mmcpart} ${fdt_addr} ${fdt_file}

loaduimage=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${uimage}

mfgtool_args=setenv bootargs console=ttymxc0,115200 rdinit=/linuxrc g_mass_storage.stall=0 g_mass_storage.removable=1 g_mass_storage.idVendor=0x066F g_mass_storage.idProduct=0x37FF g_mass_storage.iSerialNumber="" enable_wait_mode=off

mmcargs=setenv bootargs console=${console},${baudrate} ${smp} root=${mmcroot}

mmcboot=echo Booting from mmc ...; run mmcargs; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if run loadfdt; then bootm ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootm; else echo WARN: Cannot load the DT; fi; fi; else bootm; fi;

mmcdev=1

mmcpart=1

mmcroot=/dev/mmcblk0p2 rootwait rw

netargs=setenv bootargs console=${console},${baudrate} ${smp} root=/dev/nfs ip=dhcp nfsroot=${serverip}:${nfsroot},v3,tcp

netboot=echo Booting from net ...; run netargs; if test ${ip_dyn} = yes; then setenv get_cmd dhcp; else setenv get_cmd tftp; fi; ${get_cmd} ${uimage}; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if ${get_cmd} ${fdt_addr} ${fdt_file}; then bootm ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootm; else echo WARN: Cannot load the DT; fi; fi; else bootm; fi;

script=boot.scr

uimage=uImage

video=mxcfb0:dev=hdmi,1920x1200M@60,if=RGB24

Environment size: 2221/8188 bytes

U-Boot >

Is there anything wrong somewhere?

Thanks,

Jason

[AnsonHuang]

Hi Jason

     I pasted of a simple guide of booting up dtb and kernel from SD/MMC, you can refer to it and have a try:

supposed uImage is flashed to 2M offset of SD, and dtb is flashed to 1M offset of SD.

Boot kernel:

1. 1) Set dtbaddr and loadaddr, default setting is incorrect, so run command “set dtbaddr 14000000” and “set loadaddr 10800000”;
2. 2) Read dtb and uImage from SD to DRAM, command is “mmc dev 0;mmc read 14000000 800 800;mmc read 10800000 1000 8000”;
3. 3) Boot up kernel with “bootm ${loadaddr} - ${dtbaddr}”;

My kernel command line is “setenv bootargs console=ttymxc0,115200n8 noinitrd no_console_suspend root=/dev/mmcblk0p1 rw rootwait;mmc dev 0;mmc read 14000000 800 800;mmc read 10800000 1000 8000;bootm ${loadaddr} - ${dtbaddr}”

[jasonjiang]

Hi Yongcai,

Your answer reminded me that I'm missing the .dtb file. My previous working u-boot/kernel didn't need it (maybe hardcoded everything), but this new u-boot/kernel DO need. After I built the .dtb file, I was able to boot.

Thank you so much.

Jason

[AnsonHuang]

Hi, Jason

     Great, then can you help close this topic? Thanks!

[jasonjiang]

I would suggest to strictly follow the instructions Ed provided here: Linux booting on IMX6 SABRESDB. It IS really working.

I didn't follow all of it the first time by skipping the dtb part, mainly because I didn't think it was necessary, since the Linux images 3.0.35 from Freescale didn't use .dtb files. Seems they hard-coded everything.

Thanks,

Jason

[YixingKong]

Jason

Had your issue got resolved? If yes, we are going to close the discussion in 3 days. If you still need help, please feel free to reply with an update to this discussion.

Thanks,

Yixing

[jasonjiang]

Actually it was not directly solved. But I got an new image from Freescale field engineer, so I stopped trying any more.

Thanks.

Jason

[YixingKong]

Jason

We are closing the DI now. If you still need help, please feel free to reply with an update to this discussion.

Thanks,

Yixing

[YixingKong]

Jason

Thanks you for your reply. As you got new image, we are going to close the discussion in 3 days. If you still need help, please feel free to reply with an update to this discussion.

Thanks,

Yixing

[AnsonHuang]

If you want to boot up L3.10.17 kernel, dtb is necessary, there is no hard coding device info for kernel.

[jasonjiang]

Hi Yongcai,

Thank you for the reply.

When I built u-boot and kernel, seems the dtb files were not built automatically. In my kernel, I found these dts files. Should I pick one of them (like imx6q-sabresd.dts) and build into .dtb file? If so, could you suggest how? I googled around and found "In a normal flow, the DTS file is edited and compiled into a DTB file using a special compiler which comes with the Linux kernel sources" from here: A Tutorial on the Device Tree (Zynq) -- Part I | xillybus.com. I'm confused what special compiler it is.

./arch/arm/boot/dts/imx6q-sabresd-hdcp.dts

./arch/arm/boot/dts/imx6sl-evk-ldo.dts

./arch/arm/boot/dts/imx6dl-sabreauto.dts

./arch/arm/boot/dts/imx6dl-sabresd.dts

./arch/arm/boot/dts/imx6sl-evk-csi.dts

./arch/arm/boot/dts/imx6dl-sabresd-ldo.dts

./arch/arm/boot/dts/imx6dl-sabresd-hdcp.dts

./arch/arm/boot/dts/imx6q-sabrelite.dts

./arch/arm/boot/dts/imx6q-sabresd.dts

./arch/arm/boot/dts/imx6dl-sabreauto-ecspi.dts

./arch/arm/boot/dts/imx6dl-wandboard.dts

./arch/arm/boot/dts/imx6q-sabresd-ldo.dts

./arch/arm/boot/dts/imx6q-sabreauto.dts

./arch/arm/boot/dts/imx6q-sabreauto-flexcan1.dts

./arch/arm/boot/dts/imx6dl-sabreauto-flexcan1.dts

./arch/arm/boot/dts/imx6q-sbc6x.dts

./arch/arm/boot/dts/imx6q-sabreauto-gpmi-weim.dts

./arch/arm/boot/dts/imx6q-sabreauto-ecspi.dts

./arch/arm/boot/dts/imx6dl-sabreauto-gpmi-weim.dts

./arch/arm/boot/dts/imx6q-arm2.dts

./arch/arm/boot/dts/imx6sl-evk.dts

Another question is: do I really need a .dtb file to boot? I didn't have it when booting with Linux 3.0.35 from Freescale.

In order to exclude other factors (SD card programming, etc.) and only to test kernel, I actually tried one more thing, which is to boot kernel from network. Here is the details:

1. Set up TFTP server on Ubuntu host, and put the kernel file uImage_3.10.17 into /tftpboot
2. on u-boot prompt, I ran these commands:
   • "setenv serverip 10.0.0.7"
   • "setenv ipaddr 10.0.0.11"
   • "tftp uImage_3.10.17" to copy kernel from Ubuntu to iMX6 RAM
   • "bootm" to boot from RAM

But the kernel hung at the very beginning:

U-Boot > tftp uImage_3.10.17

Using FEC device

TFTP from server 10.0.0.7; our IP address is 10.0.0.11

Filename 'uImage_3.10.17'.

Load address: 0x12000000

Loading: #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #################################################################

         #########################################

         1.1 MiB/s

done

Bytes transferred = 5201216 (4f5d40 hex)

U-Boot > bootm

## Booting kernel from Legacy Image at 12000000 ...

   Image Name:   Linux-3.10.17

   Image Type:   ARM Linux Kernel Image (uncompressed)

   Data Size:    5201152 Bytes = 5 MiB

   Load Address: 10008000

   Entry Point:  10008000

   Verifying Checksum ... OK

   Loading Kernel Image ... OK

OK

No gpc device node -9, force to ldo-enable.

Starting kernel ...

I also downloaded the latest Yocto kernel source code (ver 3.10.3) from linux-yocto-3.10 - Linux 3.10 Embedded Kernel, built and tried to boot from network, and got the exact same symptom. I'm wondering if there's anything wrong in my build process. This is how I built it (I mentioned previously, and I was able to build u-boot with the same process (with different defconfig of course):

• export PATH=/opt/freescale/usr/local/gcc-4.6.2-glibc-2.13-linaro-multilib-2011.12/fsl-linaro-toolchain/bin/:$PATH
• export ARCH=arm
• export CROSS_COMPILE=arm-none-linux-gnueabi-
• make imx_v7_defconfig
• make uImage LOADADDR=0x10008000

Could you comment?

Thanks a lot,

Jason

[fabio_estevam]

Hi Jason,

Sorry, but I have no experience with buildroot.

I would suggest you to send an email to the buildroot mailing list.

Regards,

Fabio Estevam