refactor(f4): use generic init system on F4 targets

[raphaelcoeffic]

This allows for a huge speed up during the boot process.

Requires #6172 and #6177.

[pfeerick]

• T15 ✅
• TX16S ✅
• V16 ✅

@richardclli Can you check this on the NB4+/EL18/PL18... doesn't seem to be working for me? Both main firmware and bootloader seem to be getting stuck. Thankful for the hard reset button on some of them so I don't need to disassemble the radio to pull the batteries!

[richardclli]

• T15 ✅

  • TX16S ✅

  • V16 ✅

@richardclli Can you check this on the NB4+/EL18/PL18... doesn't seem to be working for me? Both main firmware and bootloader seem to be getting stuck. Thankful for the hard reset button on some of them so I don't need to disassemble the radio to pull the batteries!

I will check it out when I have time. No need to merge it in rush.

[richardclli]

Not working for Flysky targets, something is missing, I think I can try to fix this.

[richardclli]

Tested:

• PL18EV ✔️
• PL18U ✔️
• NB4P ✔️
• EL18 ❌
• NV14 ❌

@raphaelcoeffic Not sure why el18 and nv14 not start up, if only flash only the firmware (aka bootloader is 2.11.1) it seems ok, but together with the bootloader, it will not start up.

[raphaelcoeffic]

@raphaelcoeffic Not sure why el18 and nv14 not start up, if only flash only the firmware (aka bootloader is 2.11.1) it seems ok, but together with the bootloader, it will not start up.

Did you hook them to SWD? This is probably the only way to find out.

[richardclli]

@raphaelcoeffic EL18 and NV14 works now. However, I found that the delaysInit() is called quite a lot of times in the boot sequence. Not sure if it need some cleanup.

The problem in EL18 and NV14 boot is due to the delay used in PCBREV detection, and since you cleaned up the SDRAM init without delays, the delay is used before init and it hangs.

Now I just put the init before using the delay to make it work, but I think the delaysInit() should be called before boardBLEarlyInit() and remove all other calls in the code, what do you think?

[pfeerick]

@raphaelcoeffic Now that the minor detail of Flysky targets,ya know, not booting has been resolved (thanks Richard!), only outstanding issue here before merge looks to be the question above ;)