Cannot build ALL architectures without SystemC (USE_SYSTEMC=0) in v23.1

[voertler]

I have Problems how to build gem5 with KConfig for all architectures, both for gem5.opt and libgem5_opt.so

Before v23.1 we could build gem5 and the library version just like this:

scons-3 --with-cxx-config --without-tcmalloc USE_SYSTEMC=0 --verbose build/ALL/gem5.opt
scons-3 --with-cxx-config --without-python --without-tcmalloc USE_SYSTEMC=0 --verbose build/ALL/libgem5_opt.so

However this leads to compile errors as described in #591 when using v23.1

So I tried as was proposed for ARM architectures in the ticket for ALL architectures

scons-3 setconfig build/ALL USE_SYSTEMC=n
scons-3 --with-cxx-config --without-tcmalloc --verbose  build/gem5.opt

However this didn't work as the gem5.opt is missing all ISA specific Simobjects.

When doing the official KConfig way from the documentation, the options --with-cxx-config --without-tcmalloc --verbose are not supported , Also I find no documentation how to build libgem5 with KConfig

scons-3 defconfig build_gem5 build_opts/ALL
scons-3 setconfig build_gem5 USE_SYSTEMC=n
scons-3 --with-cxx-config --without-tcmalloc --verbose  build_gem5/gem5.opt

So what is the official way to build gem5.opt without integrated systemc and the corresponding libgem5 ?

Affects version
v23.1

[voertler]

Just an addtitional thing. I use the --verbose option to create a compile_commands.json based on the compile commands executed, as scons seems not be able to create one

[rogerchang23424]

The build way with cutomized option is change in the #69

So I tried as was proposed for ARM architectures in the ticket for ALL architectures

scons-3 setconfig build/ALL USE_SYSTEMC=n scons-3 --with-cxx-config --without-tcmalloc --verbose  build/gem5.opt

It should be
scons-3 defconfig build/ALL build_opts/ALL scons-3 setconfig build/ALL USE_SYSTEMC=n scons-3 --with-cxx-config --without-tcmalloc --verbose  build/ALL/gem5.opt

However this didn't work as the gem5.opt is missing all ISA specific Simobjects.

When doing the official KConfig way from the documentation, the options --with-cxx-config --without-tcmalloc --verbose are not supported , Also I find no documentation how to build libgem5 with KConfig

scons-3 defconfig build_gem5 build_opts/ALL scons-3 setconfig build_gem5 USE_SYSTEMC=n scons-3 --with-cxx-config --without-tcmalloc --verbose  build_gem5/gem5.opt

For building libgem5.so, just simply change to build_gem5/gem5.opt to build_gem5/libgem5_opt.so

[voertler]

It should be

scons-3 defconfig build/ALL build_opts/ALL scons-3 setconfig build/ALL USE_SYSTEMC=n scons-3 --with-cxx-config --without-tcmalloc --verbose build/ALL/gem5.opt

Have you tried this v23.1 or the head version?

The documentation says https://www.gem5.org/documentation/general_docs/kconfig_build_system/
Note: In order to maintain backward compatibility with the old build scheme, users need to avoid using the “build” directory for Kconfig builds.

Also I got errors that the options --with-cxx-config --without-tcmalloc --verbose are not supported, but I didn't use the build directory and rather the gem5_build directory as the documentation says to use

[rogerchang23424]

@voertler

Have you tried this v23.1 or the head version?

Yes, we can build gem5.opt without systemc by running three commands. You can checkout the Kconfig options in the build/ALL/gem5.build/config before running third option.

The documentation says https://www.gem5.org/documentation/general_docs/kconfig_build_system/
Note: In order to maintain backward compatibility with the old build scheme, users need to avoid using the “build” directory for Kconfig builds.

It means when you want to simple build gem5 with given ISA option in the build_opts. We can just build gem5 instance with the command scons build/{ISA}/gem5.opt without kconfig command. If the folder build/{ISA} is not exist, the scons will run defconfig to initial the kconfig build_opts/{ISA} options to the build dir build/{ISA} then impicitly before building the gem5 binary. So if the user want to use kconfig commands specify the build directory. The user should not use "build" as build directoy. However , build/foo, build/foo/var work in the case.

Also I got errors that the options --with-cxx-config --without-tcmalloc --verbose are not supported, but I didn't use the build directory and rather the gem5_build directory as the documentation says to use

These options should be used in the thiry command(compile gem5 to binary command).

Feel free to leave comments if any concert.