BLE crash fixing (Part ?)

[Ralim]

• Please check if the PR fulfills these requirements

• The changes have been tested locally (Via @gamelaster )
• There are no breaking changes (AFAIK)

• What kind of change does this PR introduce?
  Continued work on Pinecil v2 doesn't work after updating to v2.21 #1661.

@gamelaster tracked down the issue for the crash was the args to printf being bad causing invalid args to malloc. This occurs in the binary blob for BLE, so not trivial to fix or patch.
Luckily by remapping printf at link time to redirect to the bfl implementation it lines up.
Now this appears that on the failing unit it will print roscal fail, which we have NFI what it means.
It appears to be a warning something internally failed to calibrate (we are guessing an RC Oscillator) but also we have found that otherwise it appears to continue with BLE working (on a sample unit count of 1).

At the least this looks to prevent the crash. Further testing to be done on if any impacts otherwise.

Would suuper love reports of this working or failing.

EDIT:
Seems to fix #1661

[PReDiToR]

Hi. I ran this up after Gamiee posted it in PineCil Pine64 channel.
It hasn't crashed on me, and is visible on my phone, I used blisp 0.0.3 on Linux (I use Arch, btw) to flash.
I'm getting full heat and the display shows 27v (Rocoren PSU and EPR cable).

[PSandro]

@gamelaster could you explain briefly how you were able to track this issue down? I was trying to get a stacktrace using openOCD but were unsuccessful. Would be nice to hear how you approached this!

[Ralim]

Hia,

To the best of my knowledge this was openocd with a debug build loaded in; and then tracing backtrace and looking at args into malloc.

@gamelaster can probably say more, I have limited knowledge here 😜

[gamelaster]

@PSandro I am at work now, but when I will come back, I will write / record the process and also explain where was the issue. :) Until that, checkout @Ralim answer 😁