Hi Hannes,
Hi,
Yes, its an eMMC. If I read your response correctly, #define CONFIG_SYS_MMC_ENV_PART Can only have 2 values, 1 & 2 is that correct ?
yes - i think so. please have a look to env_mmc.c, lines 65 to 120 may be the most interesting for you. There are only low-level operations performed, nobody doesn't care about any filesystem or "filesystems-partitiontable" at this time.
Pls also keep in mind that from linux, it works fine, with fw_env.config set to /dev/mmcblk0p4 0 0x10000
i think this environment is its own instance and has no interaction with u-boot`s one, is that so? In fact this environment is within "User-Area" of eMMC and at the place were part #4 starts.
best regards, hannes
From: Hannes Petermaier Hannes.Petermaier@br-automation.com To: "Naitik Amin" Naitik.Amin@ametek.com, Cc: u-boot@lists.denx.de, u-boot-bounces@lists.denx.de Date: 09/01/2014 12:54 AM Subject: Re: [U-Boot] uboot env in mmc partition
HI there,
Hi Naitik,
I recently made changes to my system, where I created a new partition
on
my mmc. (mmcblk0p4)
do you use MMC or eMMC ? I guess eMMC.
Then i dd'd a uboot env image into this partition, updated the fw_env.config to point to /dev/mmcblk0p4. At this point, my
fw_printenv
and fw_setenv work good. So as a next step, I am tried to modify uboot
to
make it point to my env image in my new partition.
I made below changes to my config header and rebuilt the uboot. On
doing
printenv from uboot, I dont see the same env that I pushed it from
linux,
infact I see it as its defined in the config header.
Can some one help ?
/* environment setting for MMC */ #ifdef CONFIG_ENV_IS_IN_MMC #define CONFIG_SYS_MMC_ENV_DEV 0 /* device 0 */ #define CONFIG_SYS_MMC_ENV_PART 4 #define CONFIG_ENV_OFFSET 0 /* just after the MBR
*/
#endif
I understand this #defines as following:
CONFIG_SYS_MMC_ENV_DEV says: use mmc-device #0 CONFIG_SYS_MMC_ENV_PART says: use partition #4 i know that u-boot is using the boot-partitions to store the
environment,
an emmc only has 2 partitions. So #4 is a an illegal paramater
CONFIG_ENV_OFFSET is an absolute address within the device/partition so
it
is not "just after the MBR", instead the environment is "instead the
MBR"
best regards, Hannes