HowToCompile.txt

If you want to compile everything, for both PiZero and PiZero 2:
(in the directory "pitrex-baremetal")
  make clean
  make

This might lead to errors if you do not have the same setup as I have.
In the file Rules.mk, there is a definition of:
MAKE_IMAGE

If that is defined, the makefiles try to copy the resulting "*.img" files to the SD card
(path given also in Rules.mk), if that is not successfull, than the make breaks.

Either comment the definition of MAKE_IMAGE out or give correct paths.

To compile all for only PiZero:   make -f Makefile.zero all BUILD_FOR=zero1
To compile all for only PiZero2:  make -f Makefile.zero all BUILD_FOR=zero2

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If you want to compile single programs, go to the respective directory and
type: 

  make clean
  make

Per default the build image is for the PiZero type that is given in the Makefile
(first line e.g. BUILD_FOR = zero2).

To compile for the other pi, either edit the make file or call the make file with the varibale definition, like:
  make BUILD_FOR=zero1

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make clean
In general "cleans" the current project.

make clean-all
Cleans the linked libraries (like all stuff in the pitrex directory) and forces them to be rebuilt.

(clean-all and clean - do different things!)
I don't think all dependencies are allways correct, so if in doubt do a:

make clean
make clean-all
make

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All object files for pizero1 are build into the directory "build".
All object files for pizero2 are build into the directory "build7".