QNX Operating System/Discussion/OSTech/RPi4 Support for eMMC?/List of Posts
 
Forum Topic - RPi4 Support for eMMC?: (8 Items)
   
Update
David Sheinberg(deleted)
04/13/2021 3:33 PM
post121378
RPi4 Support for eMMC?   
I've been successfully using the BSP 7.1 for a Model 4B, and recently have been exploring the compute module and its IO 
Board.  I have a CM with eMMC and after setting up the eMMC and mounting as an external partition, I can get the system 
up and running, and it seems to work as expected.  I'd be very interested to get the CM eMMC mounted after the machine 
is up, and I suspect that some combination of options to devb-sdmmc-bcm2711 could work (but I could be completely wrong 
about that!).  Is this possible, and if so, does anyone have pointers for options to pass to get the eMMC seen by QNX?
Geoff Roberts
04/26/2021 2:55 AM
post121398
Re: RPi4 Support for eMMC?   
After looking around a bit it seems to me that there is no eMMC on the RPi4. Pity...

No RTC either (lame excuse as to why not is given). A pity about that also - I have to resort to to an I2C module. The 
provision of the I2C and SPI drivers with the BSP is very much appreciated!  Hopefully I can figure out how to use them!
 :-)

Geoff.
Elad Lahav
04/26/2021 3:42 PM
post121399
Re: RPi4 Support for eMMC?   
> No RTC either

What do you mean by that?

--Elad
Geoff Roberts
04/26/2021 6:13 PM
post121400
Re: RPi4 Support for eMMC?   
> > No RTC either
> 
> What do you mean by that?
> 
> --Elad


Real Time Clock. Battery backed that is.

Apparently they wanted to save on expense and space taking the view that RPi's will be connected to the internet where 
they can obtain time from somewhere else. Otherwise enter it manually.

There are various I2C (and probably SPI) battery backed RTC modules available so I have ordered a couple in to play with
.

I'm not too cut up though. The Xilinx MPSoC's don't have one either and the ZCU102 is about 50 times the price of an 
RPi4. So I was going to have to address this deficiency anyway.
Elad Lahav
04/26/2021 10:14 PM
post121401
Re: RPi4 Support for eMMC?   
Sorry, I was confused. I thought you meant a lack of support in the QNX BSP for a RTC, but now that I read your message 
again you are talking about the hardware.
Yes, whatever add-on you get should work with SPI/I2C/GPIO, I would assume. There is also PCI, but it seems only to be 
able to service the XHCI module.

--Elad
Geoff Roberts
05/07/2021 2:13 AM
post121411
Re: RPi4 Support for eMMC?   
> I've been successfully using the BSP 7.1 for a Model 4B, and recently have 
> been exploring the compute module and its IO Board.  I have a CM with eMMC and
>  after setting up the eMMC and mounting as an external partition, I can get 
> the system up and running, and it seems to work as expected.  I'd be very 
> interested to get the CM eMMC mounted after the machine is up, and I suspect 
> that some combination of options to devb-sdmmc-bcm2711 could work (but I could
>  be completely wrong about that!).  Is this possible, and if so, does anyone 
> have pointers for options to pass to get the eMMC seen by QNX?

I just discovered (yesterday) that there is a flavour of RPi4 called the "Compute Module 4". It has both eMMC and RTC 
installed so David's question makes sense to me now.

I don't have one (yet). I am expecting RTCC (I2C) modules to arrive next week for the plain vanilla RPi4's I have that 
use the DS3231 chip for which I will write a suitable RTC utility that acts like the QNX rtc utility. Hopefully the CM4 
uses the same chip. I already did one for the Xilinx board using i2c (using the I2C PMOD) that works pretty well. But 
different chip. Always fun!

I am now also keen to see if eMMC will work.

Geoff.
Geoff Roberts
06/21/2021 6:37 AM
post121463
Re: RPi4 Support for eMMC?   
Has anyone managed to get the RPi Compute Module 4 (CM4) working with eMMC, or the CM4 Lite working with SDMMC?  If so, 
what's the trick?

With the CM4 Lite (that has no eMMC but SDMMC on the I/O board instead) when I get to run the SDMMC driver (from the 
normal IFS) it can't find the SDMMC hardware. But it's fine with a common RPi4. Has the SDMMC address changed with these
 CM4 boards?

It's interesting that the CM4 can start up with the ifs-rpi4.bin I normally use and establish a shell on /dev/ser1 (as 
normal). So it can obviously see the SDMMC at this stage. But I simply can't run the SDMMC driver without it complaining
 about the lack of SDMMC hardware. Which means I can't mount a QNX6 filesystem (no /dev/sd0 or partitions).

Any help appreciated.

Geoff.
Elad Lahav
06/21/2021 6:49 AM
post121464
Re: RPi4 Support for eMMC?   
I don't have a compute module, and you may want to ask the question on the RPi forums.
However, the fact that it runs the IFS from the SD card doesn't mean that the QNX OS can see the card - the IFS is 
copied from the card to memory by the RPI's firmware. The board may or may not have ful support for SD cards (in theory 
it just needs the bare minimum to read a FAT partition).

--Elad

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