On Fri, Jan 04, 2019 at 05:56:53PM -0200, Fabiano Rosas wrote: > These will be used to let GDB know about PPC's Special Purpose > Registers (SPR). > > They take an index based on the order the registers appear in the XML > file sent by QEMU to GDB. This index does not match the actual > location of the registers in the env->spr array so the > gdb_find_spr_idx function does that conversion. > > Signed-off-by: Fabiano Rosas <[email protected]> > --- > target/ppc/translate_init.inc.c | 50 +++++++++++++++++++++++++++++++++ > 1 file changed, 50 insertions(+) > > diff --git a/target/ppc/translate_init.inc.c b/target/ppc/translate_init.inc.c > index 03f1d34a97..f10a3637d9 100644 > --- a/target/ppc/translate_init.inc.c > +++ b/target/ppc/translate_init.inc.c > @@ -9483,6 +9483,56 @@ static bool avr_need_swap(CPUPPCState *env) > #endif > } > > +#if !defined(CONFIG_USER_ONLY) > +static int gdb_find_spr_idx(CPUPPCState *env, int n) > +{ > + int idx = -1; > + int i; > + > + for (i = 0; i < ARRAY_SIZE(env->spr_cb); i++) { > + ppc_spr_t *spr = &env->spr_cb[i]; > + > + if (spr->name && ++idx == n) { > + break; > + } > + } > + return i; > +}
This is very subtle - it relies on the fact that you also generate the
XML in sequence, which makes for a very non-obvious dependency between
different parts of the code. At the very least this needs a big fat
comment explaining how the gdb ids are allocated.
I think better would be to explicitly put a gdb_id into the spr_cb
structure - that would be filled in at the same time you generate the
XML, then referenced here.
> +static int gdb_get_spr_reg(CPUPPCState *env, uint8_t *mem_buf, int n)
> +{
> + int reg;
> + int len;
> +
> + reg = gdb_find_spr_idx(env, n);
> + if (!reg) {
> + return 0;
> + }
> +
> + len = TARGET_LONG_SIZE;
> + stn_p(mem_buf, len, env->spr[reg]);
> + ppc_maybe_bswap_register(env, mem_buf, len);
> + return len;
> +}
> +
> +static int gdb_set_spr_reg(CPUPPCState *env, uint8_t *mem_buf, int n)
> +{
> + int reg;
> + int len;
> +
> + reg = gdb_find_spr_idx(env, n);
> + if (!reg) {
> + return 0;
> + }
> +
> + len = TARGET_LONG_SIZE;
> + ppc_maybe_bswap_register(env, mem_buf, len);
> + env->spr[reg] = ldn_p(mem_buf, len);
> +
> + return len;
> +}
> +#endif
> +
> static int gdb_get_float_reg(CPUPPCState *env, uint8_t *mem_buf, int n)
> {
> if (n < 32) {
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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