[U-Boot] SPL broken on i.mx31 platforms

Helmut Raiger
2014-07-02T07:04:46Z

Hi,
> Hi,
>
> the commit 41623c91 breaks the SPL on i.mx31 platforms.
> The original startup code (start.S) was position independent to
> allow relocation in board_init_f. This is necessary as the internal
> RAM used by the IPL to load the first 2kB from NAND is also
> used by the NAND controller to buffer pages.
> As far as the issue goes: where and how exactly is the code not
> position independent now?
The first statement is now:

ldr pc, _reset
_reset: .word reset

reset is an address generated by the linker (here 0x87dc0060).
Originally this was:

b reset

which is a relative branch (here 0x60 bytes forward).
I have to add, that changing this back does not fix the issue, something
else is in disorder.
I'm still working on it.

>>> Does changing the startup code back to PIC generate any
>>> drawbacks on other ARM platforms?
> How would this changing back to PIC be implemented? Not by reverting
> the patch, I hope.
No, it will only be a minor change, I think, but I thought there might
have been an additional intention behind the change to position
dependent code. One could link the first part to 0xB8000000
(the original position of the SPL when loaded by the IPL) and
the part after the relocation to CONFIG_SPL_TEXT_BASE.
>>> What was the intention of the change besides unifying?
> Any other intent would be stated in the commit message.
Ok, so the PIC issue was just an oversight.

> Maybe Albert, Stefano or Magnus could help?
> I don't have mx31 hardware either.
>
>
It seems we are the only ones still dealing with this old lad ;-)

Helmut

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