Dear Stefano,
In message 4F898CA5.8070308@denx.de you wrote:
The start address CONFIG_SYS_MEMTEST_START is the lowest address of the SDRAM that can be accessed, that is MMDC0_ARB_BASE_ADDR (0x10000000) for i.MX6.
But it _should_ be the lowest address that can _safely_ be used for such tests, i. e. the range MEMTEST_START - MEMTEST_START must neither contain the exception vectors, not U-Boot's code, stack or malloc arena.
dynamically, also the last RAM address that can be tested should be computed at run time and not at compile time with CONFIG_SYS_MEMTEST_END.
CONFIG_SYS_MEMTEST_END is NOT the end of physical RAM, but the end of the range that can be tested without crashing U-Boot...
So I will be for a patch that changes the behavior of mtest and computes automatically the last testable address if the second parameter is not given, dropping CONFIG_SYS_MEMTEST_END - I know, this is not part of your patch, I have already said I can be OT ;-)
Such a patch would be wrong.
Best regards,
Wolfgang Denk