I tried to build the espressobin u-boot only with the command given in the docs: 

./compile.sh 'compile_uboot'

But I get

...
  COPY    u-boot.bin
  CFGCHK  u-boot.cfg
rm: missing operand
Try 'rm --help' for more information.
[ o.k. ] Building flash-image-DDR3-512m_1cs_0-600_600.bin 
cp: cannot stat 'build/a3700/debug/flash-image.bin': No such file or directory
[ o.k. ] Building flash-image-DDR3-512m_2cs_0-600_600.bin 
cp: cannot stat 'build/a3700/debug/flash-image.bin': No such file or directory
...

Do I need more/different parameters or a different config-default.conf ?

Sorry for these maybe stupid questions, I am aware that I don't really see through the build system yet... 

58 minutes ago, barish said:

./compile.sh 'compile_uboot'

But it works properly if you build without this additional parameter?

If I build all it works fine (but takes a long time, and I want to experiment with u-boot parameters).

Well, I am building all then, time is not everything...

 

The resulting U-Boot gives me a version string: 

U-Boot 2018.03-devel-18.12.3-gc9aa92ce70-armbian

Does this mean that U-Boot version is 2018.03? If so, how can I possibly change to a current U-Boot?

1 minute ago, barish said:

how can I possibly change to a current U-Boot?

Fork the repo and change the version matching your board here: https://github.com/armbian/build/tree/master/config/sources/families

Expect troubles. Often there is a reason why for a particular board the u-boot version source is either forked repo itself or a few versions behind.

Many thanks, Werner, for the hint! I just found out that we have no direct influence on the U-Boot since it is also provided by Marvell/Globalscaletechnologies and they do not provide a newer version.

I finally managed to get a stable U-Boot for my EspressoBin v7 with 1GB DDR4. I changed lib/main.sh to replace github.com/MarvellEmbeddedProcessors/A3700-utils-marvell with github.com/globalscaletechnologies/A3700-utils-marvell as well as some other lines – would there be a more elegant way to patch this, I would love to know?

 

I changed config/sources/families/mvebu64.conf too to use the repository by GlobalscaleTechnologies and I even tried out the current U-Boot 2020.10 instead of Marvell's old U-Boot – I have not encountered any errors. Should I make a pull request for these changes?

 

Edit: Or better make a pull request upstream...?

 

Sure you can do a PR on this change to the build repository so maintainers can have a look at it.