RPi4B: emmc2bus dma-range handling does not track the boot-time-FDT (u-boot based booting)

[Klaus Cucinauomo]

> Am 09.10.2020 um 21:25 schrieb Mark Millard <marklmi at yahoo.com>:
> 
> 
> Linux has its own dts/dtsi/... sources instead of using the .dtb files
> from the RPi folks, not directly based on any vintage of the RPi .dtb
> files if I understand right……………..

FreeBSD imports the linux-dts :
https://github.com/freebsd/freebsd/tree/master/sys/gnu/dts/arm64/broadcom


> ………. I use apt to update the ubuntu microsd card once and a while.

I simply used the Raspberry Pi Imager(automatically updates itself to latest)
 to get a „reproducible" `latest`- msdos-partition of Ubuntu :
https://www.raspberrypi.org/downloads/
And it booted FreeBSD on the 4GB-model from SSD(w/o SD-card) (until reported hang)
( additionally I changed in config.txt from disable-bt to miniuart-bt)

…….
> 
> ….. („USB MSD boot also requires
> the firmware from Raspberry Pi OS 2020-08-20 or newer.")

Yes, , eeprom-update is a MustHave for 2020.10 USB-boot,
it also can be done by formatting an firmware-SD-card with 
the Raspberry Pi Imager - tool .

My GUESSED(my favorite term since some time :-)  following steps for the 8GB-model should be:

'Special Agent kevans‘ 
could inspect the following for dts and perhaps adopt it to fbsd-values for an early 
VL805-controller reset in u-boot :
(That patches are not upstreamed yet afaik)
https://patchwork.ozlabs.org/project/linux-pci/patch/20200629161845.6021-4-nsaenzjulienne@suse.de/
https://patchwork.ozlabs.org/project/linux-pci/patch/20200629161845.6021-5-nsaenzjulienne@suse.de/

Then we probably need `Special Agent Crowston’ again
with his JTAG-Debugger 
to read out the values where exactly Fbsd-boot-kernel hangs in 2020.10 booted off of pure USB .

.. sounds all quite easy , but possibly isn’t , as we know…

Regards
K.