[U-Boot] migration from Micron to ISSI RAM

[Detlev Zundel]

Hi Mauro,

The U-Boot you work with is pretty old.  Usually we can not help with
such old software, but in this case I can give you some general remarks.

>      Continuing with this subject. I didn't mention the registers values
> posted last email was already changed for ISSI RAM. Having said that, I have
> 3 different *write errors msgs and contexts*. Althought they look the same,
> they are:
>
>    - *Memory (date line) error at 00000000, wrote cccccccccccccccc, read
>    89abcdef89abcdef ! **...*

You can for example do a "grep -r '(date line) ." in the toplevel source
directory to find the file where the message is produced.  In a recent
U-Boot it looks like it comes from post/drivers/memory.c function
memory_post_dataline.  Studying the code in there, it seems like the
very first write (check the patterns that will be used, 0xcc... is the
first) to memory (address 0) does not succeed.  The 0x89abcdef89abcdef
look like they are the "cleaner pattern" to reset the data bus after a
write.  So in essence, the message for me translates to reads "not even
the first write to memory works".  There must be a pretty fundamental
problem with your RAM setup.

>    - Memory error at 0000018c, wrote 00000000, read 0000ff77 !

This seems to be from memory_post_test1. Again in current code this
must be the first invocation of the function (as it tries to write 0s).
Again - not even one write and a subsequent read works.

>    - Memory (address line) error at 000007f8<->000007fc, XOR value 00000004

This is from memory_post_addrline.  Again, the results from a read do
not coincide with what was written.

In essence, is seems like no write and subsequent read work for your
RAM.  You really have a fundamental problem.  You will need to check the
whole RAM initialization.  If it helps, then maybe come up with the
register values and test them with a JTAG debugger before going further.

Cheers
  Detlev

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