[dpdk-dev] [PATCHv4 5/5] pmdinfo.py: Add tool to query binaries for hw and other support information

[Thomas Monjalon]

2016-05-25 13:47, Neil Horman:
> On Wed, May 25, 2016 at 07:22:39PM +0200, Thomas Monjalon wrote:
> > 2016-05-24 15:41, Neil Horman:
> > > Note that, in the case of dynamically linked applications, pmdinfo.py will scan
> > > for implicitly linked PMDs by searching the specified binaries .dynamic section
> > > for DT_NEEDED entries that contain the substring librte_pmd.
> > 
> > I don't know any DPDK app dynamically linked with a PMD (with DT_NEEDED).
> I know lots of them, they're all in the dpdk.  everything under app that uses a
> virutal device links at link time to librte_pmd_bonding and librte_pmd_pipe (and
> a few others), because they have additional apis that they need to resolve at
> load time.

Oh yes! you are right.

> > However it is a good idea to handle this case.
> > But relying on the name assumption "librte_pmd" is really weak.
> > 
> > > +	$(Q)$(call rte_symlink,    $(DESTDIR)$(datadir)/tools/pmdinfo.py, \
> > > +				   $(DESTDIR)$(bindir)/pmdinfo)
> > 
> > I think we must prefix the tool name with dpdk.
> > What about dpdk-objinfo or dpdk-pmdinfo?
> > 
> > > +from elftools.elf.elffile import ELFFile
> > > +from elftools.elf.dynamic import DynamicSection, DynamicSegment
> > > +from elftools.elf.enums import ENUM_D_TAG
> > > +from elftools.elf.segments import InterpSegment
> > > +from elftools.elf.sections import SymbolTableSection
> > 
> > Should it be possible to implement pmdinfogen with this
> > Python library?
> > 
> Sure, but that really doesn't buy us anything, as its already implemented in C.
> In fact, I would assert its harmful, because it implies that the build
> environment needs to have python installed, as well as the pyelftools library,
> which we don't need if we build from C.

Right