[hanspeter]

the memchecker seems to run fine with up and including 628M. With 629M, it freezes after a few Stuck-Adress-Loops:

Is this different with total_mem=1008 present and absent?

yes, it's lowered by 16MB, 613M works, 614M freezes:

Code:

./memtester 613M
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 613MB (642777088 bytes)
got  613MB (642777088 bytes), trying mlock ...locked.
Loop 1:
  Stuck Address       : testing  11^C

./memtester 614M
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 614MB (643825664 bytes)
got  614MB (643825664 bytes), trying mlock ...locked.
Loop 1:
  Stuck Address       : testing   1

same behavior also with the bootcode.bin from #1119, freezes with 614M. Is this expected, or is the memtester freezing with a large value already a symptom of this problem...?

edit: just tested another RPi2 with LibreElec #1122, memtester behaves the same and crashes with 614M...