Need to support hardware variants with multiple possible ECC locations

[shawaj]

It turns out that Syncrobit miners have several possible locations for the ECC key on the i2c bus...

NebraLtd/helium-syncrobit#2

We should add handling for this scenario

[pritamghanghas]

mfr throws exec error if we try to read a slot that is not programmed before.

root@78eef93a415c:/opt# ./python-dependencies/hm_pyhelper/gateway_mfr_aarch64 --device 'ecc://i2c-7:96?slot=5' key
Error: ecc608 error

Caused by:
    ecc error ExecError

Between i2cdetect and cycling through the slots, we can probably find out the correct combo. Assuming that multiple slots were not programmed.

[shawaj]

@pritamghanghas sadly I've found that sometimes multiple are programmed. See output here...

NebraLtd/helium-syncrobit#2 (comment)

[shawaj]

Also, currently the i2c address on the bus is hard coded in diagnostics - https://github.com/NebraLtd/hm-diag/blob/master/hw_diag/utilities/hardware.py#L235

This address is 0x60 / decimal 96 which is in the swarm key uri already for example ecc://i2c-1:96?slot=0

We should change this also at same time

Ref - NebraLtd/hm-diag#500

Also see https://nebraltd.slack.com/archives/C024BNQ1Y6T/p1678578139710139

[shawaj]

This will also need significant updates in:

• hm-miner
• hm-block-tracker

[shawaj]

This PR is a partial fix for Syncrobit multi key issue:
#230

This will solve the vast majority of cases. However some will still need to be overridden with a SWARM_KEY_URI_OVERRIDE device variable currently.

In order to provide a complete fix, we still need to implement the following:

• if we have definitions in hardware variants for multiple different slots on the same i2c address then:
  • Check keys on public API. If one is found, then use that one
  • If none of the available keys are found on public API, check the onboarding server
  • If only one is found, use that one
  • If multiple found on onboarding server, use the first valid one for onboarding

We also need to pythonise the miner start scripts (or portions of it) to override the keyslot in the sys.config. Or to publish the determined key as an environment variable that the miner can ingest... But that seems more convoluted.

Ref https://github.com/syncrobit/chameleonos/blob/main/board/common/overlay/etc/init.d/S31hwdetect

[shawaj]

Ref https://github.com/helium/onboarding-server

Ref https://onboarding.dewi.org/api/v2/hotspots/11n6ApbTNiNhCLf84Hm3mZGDyqNhP83dsj4Cvj2juTXuKD7byf