It is often not easy to use company network to flash application, due to network security (proxy, etc...). We will see in this tutorial, how to flash a Linux application in a SD card with ONLY a SD card reader and simple standard Linux commands.
SD card Memory Map
A Linux application is divided in 3 parts:
- the bootloader
- the Linux Kernel
- the Linux Rootfs
We will flash sequentially these 3 parts
Flashing U-boot
With the SD card Reader, we will flash the yellow part. In the [...]/ltib/rootfs/boot/ folder
$ sudo dd if=u-boot.bin of=/dev/sdb bs=512 skip=2 seek=2 && sudo sync
Flashing Linux Kernel
With the SD card reader, we will flash the green part. Keep in mind that 1MB=1048576B -> Kernel Offset.
$ sudo dd if=uImage of=/dev/sdb bs=1048576 seek=1 && sudo sync
Configure U-boot variables
To launch the Kernel, you need to configure U-boot.
- Plug the serial cable on the EVK:
115kbps, 8 bits, 1 stop and no parity
- EVK switches must be configured as below:
| DS1 | DS2 | DS3 | DS4 | DS5 | DS5 | DS7 | DS8 | DS9 | DS10 | |
| Boot from SD/MMC Card | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 |
- Put the SD card in the EVK (bottom slot) and launch the app. In the hyperterminal type:
BBG U-Boot > printenv
To print environnement variables
- Modify the bootcmd:
BBG U-Boot > setenv bootcmd_mmc 'run bootargs_base bootargs_mmc;mmc read 0 ${loadaddr} 0x800 0x1800;bootm' "0x1800" is the size of the kernel. Must be bigger than uImage Kernel file (0x1800x512Byte=3MB)
- If you want to use the WVGA as display screen (kernel need to be configured with CLAA support), for LTIB1007 and after (before it was 'wvga' option):
Script for LTIB1007's u-boot on i.MX51 EVK (copy/paste in the hyperterminal):
setenv bootcmd_mmc 'run bootargs_base bootargs_mmc; mmc read 0 ${loadaddr} 800 1800 ; bootm'
setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/mmcblk0p1 rootwait rw init=/init' setenv bootargs_base'
setenv bootargs console=ttymxc0,115200 di1_primary console=tty1'
setenv bootcmd 'run bootcmd_mmc'
saveenv
Script for LTIB1007's u-boot on i.MX53 EVK (copy/paste in the hyperterminal):
setenv bootcmd_mmc 'run bootargs_base bootargs_mmc; mmc read 0 ${loadaddr} 800 1800 ; bootm'
setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/mmcblk0p1 rootwait rw init=/init'
setenv bootargs_base 'setenv bootargs console=ttymxc0,115200 di0_primary console=tty1'
setenv bootcmd 'run bootcmd_mmc'
saveenv
- You must have the following printenv:
BBG U-Boot > printenv
bootdelay=3
baudrate=115200
loadaddr=0x90800000
netdev=eth0
ethprime=FEC0
uboot_addr=0xa0000000
uboot=u-boot.bin
kernel=uImage
bootargs_nfs=setenv bootargs ${bootargs} root=/dev/nfs ip=dhcp nfsroot=${serveri
p}:${nfsroot},v3,tcp
bootcmd_net=run bootargs_base bootargs_nfs; tftpboot ${loadaddr} ${kernel}; boot
m
load_uboot=tftpboot ${loadaddr} ${uboot}
ethact=FEC0
bootargs=console=ttymxc0,115200 di1_primary root=/dev/mmcblk0p1 rootwait rw init
=/init
bootcmd_mmc=run bootargs_base bootargs_mmc; mmc read 0 ${loadaddr} 800 1800 ; bo
otm
bootargs_mmc=setenv bootargs ${bootargs} root=/dev/mmcblk0p1 rootwait rw init=/i
nit
bootargs_base=setenv bootargs console=ttymxc0,115200 di1_primary
bootcmd=run bootcmd_mmc
stdin=serial
stdout=serial
stderr=serial</br>
Environment size: 748/131068 bytes
BBG U-Boot >
Create ext3 partition
With the SD card reader, create an ext3 partition. You can use gparted, a graphical partition manager tool. Launch gparted:
$ sudo gparted
Create a new ext3 partition, with 20MB of offset:
Copying Linux
To copy rootfs folder generated by LTIB, type in the shell:
$ sudo cp -r /[…]/ltib/rootfs/* /media/FreescaleSD/ && sudo sync
Test application
Put the SD in the slot slot and launch the application. Password is root.
