Hello,
We observe a phenomenon on a custom board that is equipped with an i.mx7d and 512MB lpddr2.
The verification of the hash value calculated on a file placed in tmp directory fails:
# dd if=/dev/urandom of=/tmp/testfile bs=1M count=50
50+0 records in
50+0 records out
#
#
# md5sum /tmp/testfile > /tmp/testmd5
# md5sum -c /tmp/testmd5
/tmp/testfile: FAILED
md5sum: WARNING: 1 of 1 computed checksums did NOT match
On the other hand a standard linux memory test succeeds on the same board:
# memtester 200 1
memtester version 4.3.0 (32-bit)
Copyright (C) 2001-2012 Charles Cazabon.
Licensed under the GNU General Public License version 2 (only).
pagesize is 4096
pagesizemask is 0xfffff000
want 200MB (209715200 bytes)
got 200MB (209715200 bytes), trying mlock ...locked.
Loop 1/1:
Stuck Address : ok
Random Value : ok
Compare XOR : ok
Compare SUB : ok
Compare MUL : ok
Compare DIV : ok
Compare OR : ok
Compare AND : ok
Sequential Increment: ok
Solid Bits : ok
Block Sequential : ok
Checkerboard : ok
Bit Spread : ok
Bit Flip : ok
Walking Ones : ok
Walking Zeroes : ok
8-bit Writes : ok
16-bit Writes : ok
Done.
What could be the reason for this behavior?
Thanks and best regards
Alex
