Yeah, been there. Wanted at91bootstrap to boot from SPI-NOR which is
_not_ Quad-SPI, and the feature request was closed with "if you wanna
do it by yourself, ask our support for help". :-/
iirc at91bootstrap can boot from raw spi-nor (yes, not UBI)
Speaking of at91bootstrap 3.x and later: It can, but only if you use
the QSPI port, it does not work with flexcom for example. See
https://github.com/linux4sam/at91bootstrap/issues/181 for reference.
Judging by the answer, we are both right, my memory was saying it works,
and apparently for some older SoCs it's also implemented, while not for
sam9x60 at the moment.
I remember using a flexcom in SPI mode was fairly simple and should work
out of the box with the existing SPI driver in at91bootstrap, just that
the flexcom mode has to be correctly configured, pinout, etc.
