Re: [9fans] P9P libthread on Debian ARM vs. makecontext et al.

["Robert Raschke" <rtrlists@googlemail.com>]

On 7/8/08, Michael Teichgräber <mt@wmipf.in-berlin.de> wrote:
> > The code in Linux.c that implements makecontext() for ARM expects this
> > struct to contain a gregs array. I'm guessing that gregs is the same
> > as the enumerated arm_* ones above. So, would I be correct in assuming
> > that gregs[13] is arm_sp and gregs[14] is arm_lr?
>
> Hi, I would say yes, as SP is r13 and LR is r14 on arm.
> To run Russ' libtask on arm7 I used the Linux-arm-asm.s and
> the arm-specific makecontext implementation from Linux.c,
> as well as the following structures.
>
> M.
> --
>
> enum {
>        NREG = 16,
> };
>
> typedef
> struct Mcontext
> {
>        u32int  gregs[NREG];    /* general registers */
> } Mcontext;
>
> typedef
> struct ucontext
> {
>        Mcontext        uc_mcontext;
>        sigset_t uc_sigmask;
>        struct {
>                void            *ss_sp;
>                u16int  ss_size;
>        } uc_stack;
>
> } ucontext_t;
>

Thanks, that's gotten me quite a bit further. I can compile the whole
lot now and run quite a few of the commands, including rc, under the
ARM qemulation. Hurrah.

Next I need to figure out why I get segfaults for some. And then try
it on real HW.

Robby