On Fri, Sep 19, 2025, at 09:17, Geert Uytterhoeven wrote:

On Thu, 18 Sept 2025 at 15:13, Arnd Bergmann [off-list ref] wrote:

quoted

On Wed, Sep 17, 2025, at 14:59, Jason Gunthorpe wrote:

quoted

On Tue, Sep 09, 2025 at 11:23:37PM +0200, Arnd Bergmann wrote:

quoted

* Microchip SAM9x7 is the newest ARMv5 chip, clearly does
  get kernel updates, and the only one I can think of with
  DDR3 support, but seems to be limited to 256MB total memory.

Are they limited to DDR3?

IIRC, someone (you? ;-) told me at ELCE that Microchip keeps on spinning
new variants of old SoCs, to accommodate the changing DDR landscape
and market.  So perhaps they also accept larger RAM sizes?

Yes, that was me. The previous SAM9x60 was released in 2020
and I think that one was an upgrade to a smaller process node,
raising the clock frequency to 600MHz and adding more modern
peripherals, but I see now that this used the same SDRAM/LPDDR/DDR2
memory controller as previous chips, with a limit of 128MB
total DRAM.

SAM9X7 in 2023 added DDR3 mode with up to 256MB according to
the datasheet, no idea why they chose not to support more,
since a 32-bit wide DDR3 bus should allow up to 1GB with two
256Mbit x16 chips that are widely available, or even more using
expensive 512Mbit x16 or 1Gbit x8 chips.

       Arnd