Whether or not does AM335x Starter Kit have a NAND flash?Where do the uboot environment variables stored in?

As the title shows, I want to know where AM335x Starter Kit saves its uboot environment variables.

I'm facing a problem now that I can't save my uboot environment variables by using command "saveenv". When I using the script "setup.sh" provided in ti-sdk-am335x-evm-05.06.00.00, there is a mistake lead to my NFS building fail that the uboot environment variables called "netargs" defined in script "setup-uboot-env.sh" cannot be found in my SK board uboot environment.

When I using "printenv", the words printed as follow:

U-Boot# printenv
autoload=yes
baudrate=115200
bootargs_defaults=setenv bootargs console=${
} ${optargs}
bootcmd=if mmc rescan; then echo SD/MMC found on device ${mmc_dev};if run loadb;
bootdelay=3
bootenv=uEnv.txt
bootfile=uImage
console=ttyO0,115200n8
ethact=cpsw
ethaddr=00:18:31:e7:db:a8
importbootenv=echo Importing environment from mmc ...; env import -t $loadaddr e
ip_method=none
kloadaddr=0x80007fc0
loadaddr=0x82000000
loadbootenv=fatload mmc ${mmc_dev} ${loadaddr} ${bootenv}
mmc_args=run bootargs_defaults;setenv bootargs ${bootargs} root=${mmc_root} roo}
mmc_boot=run mmc_args; run mmc_load_uimage; bootm ${kloadaddr}
mmc_dev=0
mmc_load_uimage=fatload mmc ${mmc_dev} ${kloadaddr} ${bootfile}
mmc_root=/dev/mmcblk0p2 rw
mmc_root_fs_type=ext3 rootwait
nand_args=run bootargs_defaults;setenv bootargs ${bootargs} root=${nand_root} n}
nand_boot=echo Booting from nand ...; run nand_args; nandecc hw 2; nand read.i }
nand_img_siz=0x500000
nand_root=ubi0:rootfs rw ubi.mtd=7,2048
nand_root_fs_type=ubifs rootwait=1
nand_src_addr=0x280000
net_args=run bootargs_defaults;setenv bootargs ${bootargs} root=/dev/nfs nfsroop
net_boot=echo Booting from network ...; setenv autoload no; dhcp; tftp ${kloada}
nfsopts=nolock
nor_args=run bootargs_defaults;setenv bootargs ${bootargs} root={nor_root} root}
nor_boot=echo Booting from NOR ...; run nor_args; cp.b ${0x08080000} ${kloadadd}
nor_img_siz=0x280000
nor_root=/dev/mtdblock3 rw
nor_root_fs_type=jffs2
nor_src_addr=0x08080000
rootpath=/export/rootfs
script_addr=0x81900000
spi_args=run bootargs_defaults;setenv bootargs ${bootargs} root=${spi_root} roo}
spi_boot=echo Booting from spi ...; run spi_args; sf probe ${spi_bus_no}:0; sf }
spi_bus_no=0
spi_img_siz=0x380000
spi_root=/dev/mtdblock4 rw
spi_root_fs_type=jffs2
spi_src_addr=0x62000
static_ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off
stderr=serial
stdin=serial
stdout=serial

We can find there is no "netargs" but the wod "net_args" which can also be found in the script "setup-uboot-env.sh" provided in ti-sdk-am335x-evm-05.05.00.00.

After I changed the "netargs" to "net_args" and inputted commands step by step ,NFS could work successfully. Although I used the command "saveenv" to save those uboot environment variables inputted, they could be used only once .Minicom shows as follow:

U-Boot# saveenv
Saving Environment to NAND...
Erasing Nand...
Attempt to erase non page aligned data

Everytime the board rebooted, those variables changed into the default environment variables again and the information printed in minicom as follow:

U-Boot SPL 2011.09 (Jul 26 2012 - 17:18:20)
Texas Instruments Revision detection unimplemented
No daughter card present
OMAP SD/MMC: 0
reading u-boot.img
reading u-boot.img


U-Boot 2011.09 (Jul 26 2012 - 17:13:38)

I2C:   ready
DRAM: 256 MiB
WARNING: Caches not enabled
No daughter card present
NAND: HW ECC Hamming Code selected
No NAND device found!!!
0 MiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
*** Warning - readenv() failed, using default environment

Net:   cpsw
Hit any key to stop autoboot: 0

As shown, uboot can't find NAND device, readenv() failed and the default environment has been chosen to use.

So, if the SK board does not have a NAND flash,where the uboot environment variables are stored in?How can I save them into my board?

0 MaciejKucia over 12 years ago

Mastermind 7925 points

There is no NAND in Starter Kit and u-boot parameters are stored on sd card like everything else.

This might be useful for you: http://processors.wiki.ti.com/index.php/AM335x_U-Boot_User%27s_Guide

Regards,
Maciej

0 Long Xiao over 12 years ago in reply to MaciejKucia

Prodigy 90 points

hi, MaciejKucia

Thanks for your reply.I have read this user guide,it seems that there is no way to save the uboot parametres permanently in Start Kit except using the file uEnv.txt saved in SD card.The reason why "saveenv" is no use is that no NAND in board and the command "saveenv" is designed only for NAND to save u-boot parameters. If there is no uEnv.txt in SD card,u-boot will try to use its default environment.

Hence, another question comes to me ,where the default environment variables store and how to change them?

In u-boot-2012.10-psp05.05.00.00/common/env_commonc.c, I find const char default_environment[ ] which contains lots of Marcoes like CONFIG_BOOTARGS,CONFIG_BOOTDELAY .I can't find where these Marcoes are defined and valued. Perhaps CONFIG_BOOTARGS has been defined and valued in kernel source code,but the others let me have no idea.

Before kernel is uncompressed and loaded in memory, lots of uboot paremeters' value are printed in minicom when perform "printenv" , so I believe these value must be set and stored in u-boot source code. So, how could I find these value in u-boot source code?

0 Norman Wong over 12 years ago in reply to Long Xiao

Guru 26430 points

U-boot uses this header files for board config. No experience with the AM335x Starter Kit. I think for the AM335x

include/configs/am335x_evm.h

See defines for CONFIG_BOOTCOMMAND and CONFIG_EXTRA_ENV_SETTINGS for default environment. See CONFIG_ENV_IS_IN_SPI_FLASH and CONFIG_ENV_IS_IN_NAND for defining location of environment.

Seems that the way the config is defined, the u-boot environment is on the media as the boot media, ie. SPI Boot then U-boot Env is in SPI Flash, NAND Boot then Env is in NAND Flash.

Some ponderings on my part. Why U-boot could not be on a different media than the boot media? Possible a pinmux conflict? I seem to remember AM335x boards use a I2C EEPROM for board identity. Why U-boot environment variables could not have stored there?

I vaguely remember calls for saveenv to to write back to the uEnv.txt or boot.scr. Don't know want came of it.

0 MaciejKucia over 12 years ago in reply to Norman Wong

Mastermind 7925 points

I believe the default settings are under following directory:

http://git.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=tree;f=board/ti/am335x;h=10791866b332a73a15a8edbf71f98e96aeda657f;hb=HEAD

Regards,
Maciej

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Whether or not does AM335x Starter Kit have a NAND flash?Where do the uboot environment variables stored in?