The NuttX support in OpenOCD relies on post file hooks to get the offsets.
You don't need to reorder them. That's more flexible than tempering with
the TCB.
Other RTOSs that use fixed offsets require a certain configuration to be
used in order to use OpenOCD.
On Mon, Nov 23, 2020, 04:10 Matias N. <mat...@imap.cc> wrote:
> Actually I just tried the approach I suggested with a quick hack to both
> openocd and nuttx and it seems
> to be working. So, this eliminates the need to hardcode offsets. A similar
> thing should be done for the size
> of the tasklist table, since it also depend on build flags.
> Anyway, I think the handling of registers is not entirely working since
> I'm getting the following:
>
> Id Target Id Frame
> 2 Thread 536871672 (Name: Idle Task, pid:0, READYTORUN) 0x2000037c in
> g_idletcb ()
> * 3 Thread 536876112 (Name: init, pid:1, RUNNING) cmd_pwd
> (vtbl=0x20001f90, argc=1, argv=0x20001e8c)
> at nsh_envcmds.c:333
>
> For some reason the thread IDs do not start at 0 and the idle task has a
> PC in SRAM?
>
> Best,
> Matias
>
> On Sun, Nov 22, 2020, at 22:36, Matias N. wrote:
> > On Sun, Nov 22, 2020, at 22:25, Brennan Ashton wrote:
> >> I generally agree at least for the larger ARM platforms where there is
> >> overhead. We have some examples that are intentionally small, but for
> most
> >> of the reference examples I think we should be making the debugging
> better
> >> out of the box.
> >
> > Yes, that is my thinking.
> >
> >>
> >> I also usually reset this to the default when I'm debugging using the
> >> nuttx-gdbinit script.
> >
> > I'm actually trying opencd support for NuttX as QtCreator integrates
> better with it
> > compared to the nuttx-gdbinit script.
> >
> > Just now trying with nrf52832-mdk:nsh, after changing TASK_NAME_SIZE, it
> seems the
> > offset for "xcp" does not match the offset in openocd (master). Looking
> at tcb_s, these
> > variables that openocd looks for are dispersed in tcb_s, with other
> variables that are optionally
> > built, which means offsets will often change.
> >
> > I'm thinking of two ways that we could have more solid support for this:
> > * Reorder these variables so that they are all together inside the
> struct (a bit intrusive, but harmless?)
> > * Define some (optional) global struct in NuttX which can hold these
> offsets
> > as constant variables. Something like:
> >
> > struct tcb_offsets_s
> > {
> > void *pid;
> > void *xcp;
> > void *task_state;
> > void *name;
> > size_t name_size;
> > };
> >
> > const static struct tcb_offsets_s g_tcb_offsets =
> > {
> > .pid = (void*)&((struct tcb_s *)(0))->pid;
> > .xcp = (void*)&((struct tcb_s *)(0))->xcp.regs;
> > .task_state = (void*)&((struct tcb_s *)(0))->task_state;
> > .name = (void*)&((struct tcb_s *)(0))->name;
> > .name_size = sizeof(((struct tcb_s *)(0))->name);
> > };
> >
> > and then have openocd look for this first to get the offsets. I haven't
> tried this and not really familiar with openocd internals but I guess it
> should be possible.
> >
> > What do you think?
> >
> > Best,
> > Matias
> >
> >>
> >> On Sun, Nov 22, 2020, 5:18 PM Matias N. <mat...@imap.cc> wrote:
> >>
> >> > While trying the integration of openocd with NuttX it was complaining
> due
> >> > to "name" not being defined, which happens when CONFIG_TASK_NAME_SIZE
> == 0.
> >> > Looking at sched/Kconfig the default for this symbol is 31, yet many
> >> > configs have this set to zero. Do you think this is due to the default
> >> > having changed at some point or is this done to minimize memory use
> in all
> >> > these boards? If the latter, maybe we need to make the default depend
> on
> >> > CONFIG_DEFAULT_SMALL and update all configs that do not have this set.
> >> >
> >> > Best,
> >> > Matias
> >>
> >
>
