make DefineCAmkESVMFileServer() more flexible

[axel-h]

• allow custom type and instance names
• allow passing files for DefineCAmkESVMFileServer(), this avoids calling AddToFileServer()
• AddToFileServer() becomes just a light wrapper
• use instance specific name for archive and lib

This allows doing customizing the file server component name and doing all in one call:

DefineCAmkESVMFileServer(
    INSTANCE "myFileServer"
    FILES
        "linux:${VM_IMG_LINUX}"
        "linux-initrd:${VM_IMG_ROOTFS}"
        "linux-dtb:${VM_IMG_DTB_PATCHED}"
    DEPENDS
        target_dtb_gen
)

See seL4/camkes-vm-examples#37 for a usage examples.

[wom-bat]

Need to investigate and fix the failing tests...

[axel-h]

Need to investigate and fix the failing tests...

Don't bother, I think I have a clue what fails there and what I have to improve to make it work. Just need to find some time to work in this again.

[axel-h]

Could I get some feedback here, any chances to merge this?

[kent-mcleod]

Nice improvement! The ability to set CPIO output paths introduced in seL4/seL4_tools#151 will need to be merged before the second commit here can be merged.

[axel-h]

Adding a feature that allows an empty file string also in DefineCAmkESVMFileServer(). This can be used for files that do no exist in every configuration. The caller can use a variable in this case instead of a fixed string, and leave the variable empty. This is used in the vm_minimal example, where not all platforms have initrd.

[axel-h]

Adding support for file lists as parameter also, because this comes handy for the existing examples.

[axel-h]

Avoid creating some unnecessary intermediate helper CMake targets.

[axel-h]

Changed the order of the commits and split them up further. That allows cherry-picking the CPIO custom folder feature without taking the change in the CMake FileServer functions.

[axel-h]

Removing the dependency of this PR on seL4/seL4_tools#151 and seL4/camkes-vm-examples#37. It's not necessary to use a specific folder, if the instance name is simply used in the file name of the archive and lib. I will make another PR to move the build artifact out out of the build root folder, so this does not block this PR.

[axel-h]

Create dedicated targets for each file server instances, and set the properties for fixed names within each target. This is cleaner than putting everything into a single vm_fserver_config target. And it allows keeping the property names FILES and DEPS, which does not break any existing usages that might exist here.

[axel-h]

Can we merge this?

[lsf37]

Since the dependency on seL4/seL4_tools#151 is gone, I think we can merge this one, yes.