Dave Martin <dave.mar...@linaro.org> wrote: > > So to summarize: the kernel will write additional note sections as if > > generated via user_regset_view, containing the PTRACE_GETVFPREGS data. > > > > Note name: "LINUX" > > Why "LINUX" and not "CORE"? I don't understand the distinction... are > the "CORE" notes common to all platforms / all ELF implementations?
Because that's what user_regset_view would do; all notes except the standard ones (NT_PRPSINFO, NT_PRSTATUS, NT_PRFPREG, NT_AUXV) have a note name of "LINUX". I'm not completely sure about the rationale, but presumably it is indeed because the standard notes are more or less common across multiple platforms. > > Note type: t.b.d. [*] > > > > [*] Looking at elf.h a logical name/value might be: > > > > #define NT_ARM_VFP 0x400 /* ARM VFP/NEON registers */ > > > > > > GDB support along those lines ought to be straightforward. > > It's been suggested that the new note should include a version/flags > field alongside the ptrace-like register dump, so that if the format > turns out to be inadequate / broken, it can be extended in a > compatible way. > > However, nothing else in the coredump or the ptrace interface seems to > have such versioning implementation. Ptrace gets extended by adding > more and more ptrace call types instead. Adding version fields, while > sensible, seems inconsistent with the current implementation. > > What's your view on adding a flags field to the VFP state dump? Again, if we want to use (or mimic) the user_regset_view mechanism, there is no choice in any of this; the content of the note will be exactly identical to the content of the ptrace buffer. Since this is the way everybody else is using, I think we'd have to have really good arguments for deviating from it; I'm not sure I see those. The usual way to deal with changes to the register set is to define *new* regset structures, which then translates to new ptrace commands and new core files notes, which are used instead of or in addition to the old ones ... Mit freundlichen Gruessen / Best Regards Ulrich Weigand -- Dr. Ulrich Weigand | Phone: +49-7031/16-3727 STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E. IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht Stuttgart, HRB 243294 _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
