Flashing an Onion with custom flash
We have made a custom PCB for the Onion Omega2S and wish to use it with our own flash memory. We are using the SDINBDG4-8G Sandisk flash chip which is an 8GB eMMC chip. Since it is a flash chip we have added ourselves we will need to flash the OS onto it.
How would be go about flashing the chip? Would it work with the normal methods (sysupgrade or via U-Boot)? I'm thinking that since the flash chip happens to be the same capacity as the Omega Onion 2 Pro, then it flashing the Omega 2S Pro firmware will simply "just work"? (Just to clarify, we aren't using the components from the Pro board at all but just the Omega 2S+ on a PCB).
@Joshua-O-Leary I have my own PCB built around Omega2S+. I use serial console to connect to my wifi, scp my custom firmware to /tmp then run sysupgrade.
It's a pain t update large numbers of devices so I'm working on a new PCB with built in Ethernet port so I can use TFTP per the Onion docs.
@crispyoz did you need to use the custom firmware in order to use your flash memory? If so how did you configure it (drivers, mountpoints etc.)?
@Joshua-O-Leary I use SDCard option.
Since it is a flash chip we have added ourselves we will need to flash the OS onto it.
No. You must flash one of Omega2 Pro firmware onto the Omega2S+ onboard flash.
For example if you want to use the latest Omega2 Pro FW (2019-10-28) then flash it onto an Omega2S+:
sysupgrade -n --force omega2pro-v0.3.2-b232.bin
The full firmware upgrade process may take up to 5 minutes and your Omega2 Pro will reboot twice!
The first reboot will happen after the firmware has been updated, then once the device initializes, it will configure everything to run from the eMMC storage, after which it will reboot again. This will only happen on the first boot after an upgrade.
It'll take about 7 (seven!) minutes.
You should not press any key during this time - it is fully automatic.
You could watch the whole process on the Serial Console.
BTW The title of this article Booting from External Storage is a marketing bullshit.
An Omega2(+), Omega2S(+) or Omega2 Pro - with any present official Onion firmware - is not able to boot from any external storage (MicroSD card, USB memory storage or eMMC).
Please take a look at my project: DIY Omega2 Pro - Try it before buy
Unfortuntely I don't have any Omega2S+ and I can't solder any BGA chip - so I've made some experimental (or "fake" Omega2 Pro for myself.