target-xtensa: add gdb support

Specific xtensa processor overlay for GDB contains register map in
the gdb/xtensa-config.c. This description is used by the GDB to e.g.
parse 'g' response packets and it may be reused in the qemu's gdbstub
(only XTREG definitions for non-pseudoregisters are needed).

Currently mainline GDB does not support operations with privileged SRs
(see http://sourceware.org/ml/gdb/2011-07/msg00075.html). This support
may be enabled, see NUM_CORE_REGS comment in the gdbstub.c

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/target-xtensa/cpu.h b/target-xtensa/cpu.h
index c9094e9..93e17d1 100644
--- a/target-xtensa/cpu.h
+++ b/target-xtensa/cpu.h
@@ -214,9 +214,23 @@ typedef enum {
     INTTYPE_MAX
 } interrupt_type;
 
+typedef struct XtensaGdbReg {
+    int targno;
+    int type;
+    int group;
+} XtensaGdbReg;
+
+typedef struct XtensaGdbRegmap {
+    int num_regs;
+    int num_core_regs;
+    /* PC + a + ar + sr + ur */
+    XtensaGdbReg reg[1 + 16 + 64 + 256 + 256];
+} XtensaGdbRegmap;
+
 typedef struct XtensaConfig {
     const char *name;
     uint64_t options;
+    XtensaGdbRegmap gdb_regmap;
     unsigned nareg;
     int excm_level;
     int ndepc;