PPC/GDB: handle read and write of fpscr

Although the support of this register may be uncomplete, there are no
reason to prevent the debugger from reading or writing it.

Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

gdbstub.c

@@ -781,7 +781,8 @@ static int cpu_gdb_write_register(CPUPPCState *env, uint8_t *mem_buf, int n)
             /* fpscr */
             if (gdb_has_xml)
                 return 0;
-            return 4;
+            store_fpscr(env, ldtul_p(mem_buf), 0xffffffff);
+            return sizeof(target_ulong);
         }
     }
     return 0;

target-ppc/cpu.h

@@ -1180,6 +1180,8 @@ void ppc_tlb_invalidate_one (CPUPPCState *env, target_ulong addr);
 #endif
 #endif
 
+void store_fpscr(CPUPPCState *env, uint64_t arg, uint32_t mask);
+
 static inline uint64_t ppc_dump_gpr(CPUPPCState *env, int gprn)
 {
     uint64_t gprv;

target-ppc/fpu_helper.c

@@ -463,6 +463,11 @@ void helper_store_fpscr(CPUPPCState *env, uint64_t arg, uint32_t mask)
     fpscr_set_rounding_mode(env);
 }
 
+void store_fpscr(CPUPPCState *env, uint64_t arg, uint32_t mask)
+{
+    helper_store_fpscr(env, arg, mask);
+}
+
 void helper_float_check_status(CPUPPCState *env)
 {
     if (env->exception_index == POWERPC_EXCP_PROGRAM &&

target-ppc/translate_init.c

@@ -7693,7 +7693,7 @@ static int gdb_set_float_reg(CPUPPCState *env, uint8_t *mem_buf, int n)
         return 8;
     }
     if (n == 32) {
-        /* FPSCR not implemented  */
+        helper_store_fpscr(env, ldl_p(mem_buf), 0xffffffff);
         return 4;
     }
     return 0;