[U-Boot] uboot env in mmc partition

[Naitik Amin]

Hi Sachin,

My paritions are not laid out in the same order of 1-4 in memory. The 
address that computed came from below

[root at IM mmcblk0p4]# ls
alignment_offset   holders            ro                 stat
dev                inflight           size               subsystem
discard_alignment  partition          start              uevent
[root at IM mmcblk0p4]# cat start
1099776

1099776 * 512 = 0x21900000




From:   Sachin Verma <simplysachin at gmail.com>
To:     Naitik Amin <Naitik.Amin at ametek.com>, 
Cc:     "Peter A. Bigot" <pab at pabigot.com>, u-boot at lists.denx.de, Hannes 
Petermaier <Hannes.Petermaier at br-automation.com>
Date:   09/03/2014 11:54 AM
Subject:        Re: [U-Boot] uboot env in mmc partition




Hi Naitik,
On Wed, Sep 3, 2014 at 8:08 PM, Naitik Amin <Naitik.Amin at ametek.com> 
wrote:
Below is the layout of my partitions.

[root at IM /root]# cat /proc/partitions
major minor  #blocks  name

 179        0    3887104 mmcblk0
 179        1      20480 mmcblk0p1
 179        2     512000 mmcblk0p2
 179        3       1024 mmcblk0p3
 179        4         64 mmcblk0p4

Further explanation
Partition 1: Partition type: 0xB Fat32 (Holds zImage, dtb, rbf, uboot
startup script)
Partition 2: Partititon type: 0x83 ext3 (Holds rootfs)
Partition 3: Partition type: A2 (raw) MBR looks for preloader at the
beginning of the A2 partition. (Holds Preloader, followed by uboot)
Partition 4: Partition type: A3 (raw) To hold the uboot-env (Newly
created)

 
According to your partition layout, your environment offset must be :  
(3887104 + 20480 + 512000 + 1024) = 4420608 blocks into the user partition 
of eMMC.
 
So, the offset should be 4420608 * 512 = 2263351296 = 0x86E80000
 
 
The offset (0x21900000) you are using seems to be in your very first 
partition i.e. mmcblk0 and hence it is corrupting your dtb and other 
files.
 
Best Regards,
Sachin Verma.