gdbserver: xtensa: add call0 support

Correctly handle a0- registers on requests from remote gdb. This fixes

  'Register 1 is not available'

and subsequent assertion in the remote gdb connecting to the gdbserver:

  'findvar.c:291: internal-error: value_of_register_lazy:
    Assertion `frame_id_p(get_frame_id (frame))' failed.'

The register structure is the same for windowed and call0 ABIs because
currently linux kernel internally requires windowed registers, so they
are always present.

gdb/gdbserver/
2017-03-27  Max Filippov  <jcmvbkbc@gmail.com>

	* linux-xtensa-low.c (xtensa_fill_gregset): Call collect_register
	for all registers in a0_regnum..a0_regnum + C0_NREGS range.
	(xtensa_store_gregset): Call supply_register for all registers in
	a0_regnum..a0_regnum + C0_NREGS range.

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 14594df..7b4c443 100644 (file)
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,10 @@
+2017-03-27  Max Filippov  <jcmvbkbc@gmail.com>
+
+       * linux-xtensa-low.c (xtensa_fill_gregset): Call collect_register
+       for all registers in a0_regnum..a0_regnum + C0_NREGS range.
+       (xtensa_store_gregset): Call supply_register for all registers in
+       a0_regnum..a0_regnum + C0_NREGS range.
+
 2017-03-13  Simon Marchi  <simon.marchi@polymtl.ca>
 
        * Makefile.in (%-ipa.o: %-ipa.c): New rule.

diff --git a/gdb/gdbserver/linux-xtensa-low.c b/gdb/gdbserver/linux-xtensa-low.c
index 98c0bf2..80b5d33 100644 (file)
--- a/gdb/gdbserver/linux-xtensa-low.c
+++ b/gdb/gdbserver/linux-xtensa-low.c
@@ -59,6 +59,20 @@ xtensa_fill_gregset (struct regcache *regcache, void *buf)
       ptr += register_size (tdesc, i);
     }
 
+  if (XSHAL_ABI == XTHAL_ABI_CALL0)
+    {
+      int a0_regnum = find_regno (tdesc, "a0");
+      ptr = (char *) &rset[R_A0 + 4 * rset[R_WB]];
+
+      for (i = a0_regnum; i < a0_regnum + C0_NREGS; i++)
+       {
+         if ((4 * rset[R_WB] + i - a0_regnum) == XCHAL_NUM_AREGS)
+           ptr = (char *) &rset[R_A0];
+         collect_register (regcache, i, ptr);
+         ptr += register_size (tdesc, i);
+       }
+    }
+
   /* Loop registers, if hardware has it.  */
 
 #if XCHAL_HAVE_LOOPS
@@ -94,6 +108,20 @@ xtensa_store_gregset (struct regcache *regcache, const void *buf)
       ptr += register_size (tdesc, i);
     }
 
+  if (XSHAL_ABI == XTHAL_ABI_CALL0)
+    {
+      int a0_regnum = find_regno (tdesc, "a0");
+      ptr = (char *) &rset[R_A0 + (4 * rset[R_WB]) % XCHAL_NUM_AREGS];
+
+      for (i = a0_regnum; i < a0_regnum + C0_NREGS; i++)
+       {
+         if ((4 * rset[R_WB] + i - a0_regnum) == XCHAL_NUM_AREGS)
+           ptr = (char *) &rset[R_A0];
+         supply_register (regcache, i, ptr);
+         ptr += register_size (tdesc, i);
+       }
+    }
+
   /* Loop registers, if hardware has it.  */
 
 #if XCHAL_HAVE_LOOPS