iMX6 TinyRex Basic U-Boot

U-Boot is a bootloader responsible for hardware initialization, loading and booting Linux kernel. It is also used for module flashing.

Build

Set toolchain

Export toolchain variables for every related terminal session.

Initial steps

Create working directory

mkdir -pv ~/workdir/imx6/bootloader/

U-Boot v2015.04

Download and extract source code

cd ~/workdir/imx6/bootloader/
git clone -b uboot-imx-v2015.04 --single-branch https://github.com/voipac/uboot-imx uboot-imx-v2015.04-rex
cd uboot-imx-v2015.04-rex

Compile

Output file is called u-boot.imx. All the compiled images are intended for production usage.

Compile for SD3 and Linux/Yocto

cd ~/workdir/imx6/bootloader/uboot-imx-v2015.04-rex
make distclean
make mx6tinyrexbasic_config
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-
cp -av u-boot.imx /srv/tftp/imx6/u-boot-imx6-tinyrexbasic.imx

Compile for SPI1 and Linux/Yocto

cd ~/workdir/imx6/bootloader/uboot-imx-v2015.04-rex
make distclean
make mx6tinyrexbasicrecovery_config
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-
cp -av u-boot.imx /srv/tftp/imx6/u-boot-imx6-tinyrexbasicrecovery.imx

How to Flash a new version

Flash Normal image into SD3

sudo dd if=u-boot-imx6-tinyrex*.imx of=/dev/sdc bs=1k seek=1 skip=0 oflag=dsync

Flash Recovery image into SPI1

setenv ipaddr 192.168.0.150
setenv serverip 192.168.0.1
mw.b 0x10800000 0xFF 0x80000
tftp 0x10800000 imx6/u-boot-imx6-tinyrex*recovery.imx
if sf probe 0:0; then sf erase 0x0 0x80000;sf write 0x10800000 0x400 0x7fc00; fi

Flashing log:

U-Boot 2015.04-g9de6034-dirty (Jan 08 2017 - 18:27:05)

CPU:   Freescale i.MX6D rev1.2 at 792 MHz
CPU:   Temperature 32 C
Reset cause: POR
Board: MX6 TinyRex - basic
I2C:   ready
DRAM:  1 GiB
MMC:   FSL_SDHC: 0, FSL_SDHC: 1, FSL_SDHC: 2
Card did not respond to voltage select!
MMC init failed
Using default environment

In:    serial
Out:   serial
Err:   serial
Net:   FEC [PRIME]
Boot from USB for mfgtools
Use default environment for mfgtools
Run bootcmd_mfg: <NULL>
TinyRex U-Boot > setenv ipaddr 192.168.1.150
TinyRex U-Boot > setenv serverip 192.168.1.1
TinyRex U-Boot > mw.b 0x10800000 0xFF 0x80000
TinyRex U-Boot > tftp 0x10800000 imx6/u-boot-imx6-tinyrexbasicrecovery.imx
Using FEC device
TFTP from server 192.168.1.1; our IP address is 192.168.1.150
Filename 'imx6/u-boot-imx6-tinyrexbasicrecovery.imx'.
Load address: 0x10800000
Loading: #######################
         3.5 MiB/s
done
Bytes transferred = 334848 (51c00 hex)
TinyRex U-Boot > sf probe 0:0;sf erase 0x0 0x80000;sf write 0x10800000 0x400 0x7fc00
SF: Detected SST25VF032B with page size 256 Bytes, erase size 4 KiB, total 4 MiB
SF: 524288 bytes @ 0x0 Erased: OK
SF: 523264 bytes @ 0x400 Written: OK
TinyRex U-Boot >

U-Boot v2014.10

Download & Extract source code

cd ~/workdir/imx6/bootloader/
git clone -b uboot-imx-v2014.10 --single-branch https://github.com/voipac/uboot-imx uboot-imx-v2014.10-rex
cd uboot-imx-v2014.10-rex

Compile

Output file is called u-boot.imx. The compiled image is intended for production usage.

Compile for Linux/Yocto

cd ~/workdir/imx6/bootloader/uboot-imx-v2014.10-rex
make distclean
make mx6tinyrexbasic_config
make
cp -av u-boot.imx /srv/tftp/imx6/u-boot-imx6-tinyrexbasic.imx

How to Flash a new version

Flash Normal image into SD3

sudo dd if=u-boot-imx6-tinyrex*.imx of=/dev/sdc bs=1k seek=1 skip=0 oflag=dsync

Configure

Manually erase configuration

env default -f -a
saveenv
reset

Manual boot options

Manually boot from SD3

mw.l 0x020d8040 0x00003040; mw.l 0x020d8044 0x10000000; reset

Manually boot from SPI1 SS0

mw.l 0x020d8040 0x08000030; mw.l 0x020d8044 0x10000000; reset

Manually boot from SD3 + recovery on SPI1 SS0

mw.l 0x020d8040 0x48003040; mw.l 0x020d8044 0x10000000; reset

Change display resolution

setenv video "video=mxcfb0:dev=hdmi,1280x720M@60,if=RGB24,bpp=32"
saveenv