i.MX8M Mini Hangs at ATF when booting from USB

[Marcel Ziswiler]

Hi Tim et al.

On Wed, 2022-02-02 at 08:27 -0800, Tim Harvey wrote:
> On Wed, Feb 2, 2022 at 3:36 AM Adam Ford <aford173 at gmail.com> wrote:

[snip]

> 
> To give some numbers to the SPL size issue here is what I've found:
> - lpddr4 dram config structs are about 3K each (I know I have 3 of
> them currently in my IMX8MM board support)
> - lpddr4 training blobs are about 51K but they get placed following
> the SPL and padded to 87K; this is a pretty big waste. Perhaps there
> is some way we can easily get rid of the padding
> - SPL_DM_USB/SPL_USB_HOST/SPL_USB_GADGET is 34K but with non-dm-usb
> support (the patches Adam is referring to) its 17K so the cost of
> SPL_DM_USB is 17K

By chance I am also looking at this trying to get our USB recovery use case going using uuu with mainline U-
Boot and I noticed a similar tightness in SPL space. Using LTO gave me a few more kilobytes but you are already
using that as far as I can tell. In addition to that padding which may be optimized we also should really have
256 KB of SRAM while currently not all of that seem used/usable.

> I know for imx8mm-venice I am down to having only a few KB left and
> will probably need it for future dram configs.
> 
> The blocker to getting non-dm-spl-usb support for IMX8M appears to be
> the base addresses and instead of adding more of them to imx-regs.h we
> need to get them from DT via of_platdata which nobody has had time to
> dig into yet.

I was also a little hesitant due to not using DM in SPL might no longer be accepted upstream. What is the
stance on this?

> Best Regards,
> 
> Tim

Thanks, Tim.

Cheers

Marcel