[PULL 3/7] target/loongarch: Fix GDB get the wrong pc

[Richard Henderson]

From: Song Gao <gaosong@loongson.cn>

GDB LoongArch add a register orig_a0, see the base64.xml [1].
We should add the orig_a0 to match the upstream GDB.

[1]: 
https://github.com/bminor/binutils-gdb/blob/master/gdb/features/loongarch/base64.xml

Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220805033523.1416837-2-gaosong@loongson.cn>
---
 target/loongarch/cpu.c       | 2 +-
 target/loongarch/gdbstub.c   | 7 +++++--
 gdb-xml/loongarch-base64.xml | 1 +
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index 1c69a76f2b..d84ec38cf7 100644
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -683,7 +683,7 @@ static void loongarch_cpu_class_init(ObjectClass *c, void 
*data)
     cc->gdb_read_register = loongarch_cpu_gdb_read_register;
     cc->gdb_write_register = loongarch_cpu_gdb_write_register;
     cc->disas_set_info = loongarch_cpu_disas_set_info;
-    cc->gdb_num_core_regs = 34;
+    cc->gdb_num_core_regs = 35;
     cc->gdb_core_xml_file = "loongarch-base64.xml";
     cc->gdb_stop_before_watchpoint = true;
 
diff --git a/target/loongarch/gdbstub.c b/target/loongarch/gdbstub.c
index 24e126fb2d..5feb43445f 100644
--- a/target/loongarch/gdbstub.c
+++ b/target/loongarch/gdbstub.c
@@ -19,8 +19,11 @@ int loongarch_cpu_gdb_read_register(CPUState *cs, GByteArray 
*mem_buf, int n)
     if (0 <= n && n < 32) {
         return gdb_get_regl(mem_buf, env->gpr[n]);
     } else if (n == 32) {
-        return gdb_get_regl(mem_buf, env->pc);
+        /* orig_a0 */
+        return gdb_get_regl(mem_buf, 0);
     } else if (n == 33) {
+        return gdb_get_regl(mem_buf, env->pc);
+    } else if (n == 34) {
         return gdb_get_regl(mem_buf, env->CSR_BADV);
     }
     return 0;
@@ -36,7 +39,7 @@ int loongarch_cpu_gdb_write_register(CPUState *cs, uint8_t 
*mem_buf, int n)
     if (0 <= n && n < 32) {
         env->gpr[n] = tmp;
         length = sizeof(target_ulong);
-    } else if (n == 32) {
+    } else if (n == 33) {
         env->pc = tmp;
         length = sizeof(target_ulong);
     }
diff --git a/gdb-xml/loongarch-base64.xml b/gdb-xml/loongarch-base64.xml
index 4962bdbd28..a1dd4f2208 100644
--- a/gdb-xml/loongarch-base64.xml
+++ b/gdb-xml/loongarch-base64.xml
@@ -39,6 +39,7 @@
   <reg name="r29" bitsize="64" type="uint64" group="general"/>
   <reg name="r30" bitsize="64" type="uint64" group="general"/>
   <reg name="r31" bitsize="64" type="uint64" group="general"/>
+  <reg name="orig_a0" bitsize="64" type="uint64" group="general"/>
   <reg name="pc" bitsize="64" type="code_ptr" group="general"/>
   <reg name="badvaddr" bitsize="64" type="code_ptr" group="general"/>
 </feature>
-- 
2.34.1