px4fmu-v2 vs px4fmu-v3 confusion

[julianoes]

I am trying to flash one of the early 3DR Pixhawks and I'm confused whether to build and flash px4fmu-v2 or px4fmu-v3 because I see conflicting information.

When I boot the Pixhawk I am informed that I should be using 1MB flash only, therefore px4fmu-v2

MCU: STM32F42x, rev. Y

WARNING   WARNING   WARNING!
Revision Y has a silicon errata:
This device can only utilize a maximum of 1MB flash safely!
https://pixhawk.org/help/errata

However, when I try to flash px4fmu-v2, the uploader does not agree:

[100%] Built target nuttx_px4fmu-v2_default.elf
[100%] uploading px4
Loaded firmware for 9,0, size: 985021 bytes, waiting for the bootloader...
Trying /dev/serial/by-id/usb-3D_Robotics_PX4_BL_FMU_v2.x_0-if00
Found board 9,0 bootloader rev 4 on /dev/serial/by-id/usb-3D_Robotics_PX4_BL_FMU_v2.x_0-if00

ERROR: Board can accept larger flash images (2080768 bytes) than board config (1032192 bytes). Please use the correct board configuration to avoid lacking critical functionality.
[100%] Built target upload

I'm assuming the uploader is wrong, right?

@davids5 could you comment?

[julianoes]

Why does the bot flag this as a bug?

[PX4BuildBot]

GitMate.io thinks a possibly related issue is #7675: Some questions about “mc_att_control” hope to get help.

[julianoes]

GitMate couldn't be more wrong.

[LorenzMeier]

The uploader is wrong, yes. This could be the result of a weird combination of Bootloader and silicon errata.

[julianoes]

@LorenzMeier ok, so you think I have "a wrong bootloader revision" ? That's possible since I might have updated these at some point.

[julianoes]

So, I can reproduce exactly the same behavior with 3 different Pixhawks, so this batch is consistent and it's probably not some bootloader that I flashed myself.

[julianoes]

The silicon check was added to the bootloader with revision 5: https://github.com/PX4/Bootloader/pull/47/files.

My pixhawks have bootloader revision 4 and therefore should be defaulted to 1MB.

[LorenzMeier]

#8811

[LorenzMeier]

My PR tries to do something more complex, it might be easier as you suggested to just default any v4 board that reports larger than 1M to 1M.

[julianoes]

Ok thanks, this let's me flash px4fmu-v2 again.

The other question is if we should prevent flashing v3 for older bootloaders where we don't know if it is safe?

[LorenzMeier]

I think we should prevent flashing > 1M images on old boot loaders, yes.

[julianoes]

Ok, do you want to add it to your PR, or should I?

[LorenzMeier]

Makes more sense if you go ahead as you have the test setup.

[julianoes]

Ok, will do.

[julianoes]

as you have the test setup.

You could call it that 😄 #moreismore

[julianoes]

@LorenzMeier done, commits added to #8811.

[dagar]

I did a quick pass and many of the newer fmu-v2/v3 boards still have bootloader version 4.

• pixhawk mini
• mRo pixhawk
• pixhack v3
• holybro pixhawk (brand new)

[julianoes]

@dagar do you agree with the change though? Or do you think we should only display a warning?
Or should we support a script that updates bootloaders?

[dagar]

The safest thing to do is stick with px4fmu-v2_default if the the bootloader is older than revision 5, but there are obviously plenty of cases where that's annoying.

[julianoes]

@dagar Ok, the change went in. Do we need to do the same for QGC?

[julianoes]

I was told on the dev call that this is correct for QGC and it looks indeed correct:
https://github.com/mavlink/qgroundcontrol/blob/af45d4ad275968332afb43d18145ccd244b200fb/src/VehicleSetup/Bootloader.cc#L586-L591

Closing.

[cdlwhm1217096231]

@LorenzMeier
I am new to this and I just followed from fresh install ubuntu 16.04 from devpx4 site and I got problem when running make px4fmu-v2_default, here is the error that I got

[100%] Linking CXX executable ../../nuttx_px4fmu-v2_default.elf
Error running link command: No such file or directory
platforms/nuttx/CMakeFiles/nuttx_px4fmu-v2_default.elf.dir/build.make:186: recipe for target 'nuttx_px4fmu-v2_default.elf' failed
make[3]: *** [nuttx_px4fmu-v2_default.elf] Error 2
CMakeFiles/Makefile2:5100: recipe for target 'platforms/nuttx/CMakeFiles/nuttx_px4fmu-v2_default.elf.dir/all' failed
make[2]: *** [platforms/nuttx/CMakeFiles/nuttx_px4fmu-v2_default.elf.dir/all] Error 2
Makefile:105: recipe for target 'all' failed
make[1]: *** [all] Error 2
Makefile:153: recipe for target 'px4fmu-v2_default' failed
make: *** [px4fmu-v2_default] Error 2

[julianoes]

@cdlwhm1217096231 this looks like a separate issue, please create a new issue for this and share all the build output, and make sure to do a make clean as well.