How to replace u-boot environment in linux

[berniechen]

Dear all

I using kernel 3.0.35, ubuntu 11.10 , and we using sd card boot, below are my arguments in u-boot

setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/mmcblk1p1 rootwait rw video=mxcfb1:dev=ldb,LDB-XGA,if=RGB666 video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB2

setenv bootcmd_mmc 'run bootargs_base bootargs_mmc;mmc dev 2;mmc read ${loadaddr} 0x800 0x2000;bootm'

setenv bootcmd 'run bootcmd_mmc'

saveenv

run bootcmd

then we can into ubuntu. Please can someone kindly indicate how to replace uboot environment from linux. What tools that I should to use?

For example, I'd like replace LDB-XGA by LDB-WGA.

Thank you..

[igorpadykov]

Hi Bernie

please look at denx suggestion

HowCanIAccessUBootEnvironmentVariablesInLinux < DULG < DENX

Best regards

igor

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[berniechen]

Hi igorpadykov

Thanks your reply. I have build fw_printenv binary. But it looks to use it for flash memory in kernel (MTD), we use sd card

but there are no MTD in our linux.

root@linaro-ubuntu-desktop: cat  /proc/mtd

                                         dev:          size                 erasesize             name        

How can I change u-boot environments in sd card in linux

Thank you.

[berniechen]

I use sd card boot

I want to print u-boot environment in linux from my sd card, fw_printenv can't to access, because we have no device file in cat /proc/mtd

Thank you..