target-arm: Add AArch64 gdbstub support

We want to be able to debug AArch64 guests. So let's add the respective gdb
stub functions and xml descriptions that allow us to do so.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: John Rigby <john.rigby@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1378235544-22290-12-git-send-email-peter.maydell@linaro.org
Message-id: 1368505980-17151-6-git-send-email-john.rigby@linaro.org
[PMM: dropped unused fp regs XML for now; moved 64 bit only functions
 to new gdbstub64.c; these are hooked up in AArch64CPU, not via
 ifdefs in ARMCPU]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

gdb-xml/aarch64-core.xml

@@ -0,0 +1,46 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2009-2012 Free Software Foundation, Inc.
+     Contributed by ARM Ltd.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!DOCTYPE feature SYSTEM "gdb-target.dtd">
+<feature name="org.gnu.gdb.aarch64.core">
+  <reg name="x0" bitsize="64"/>
+  <reg name="x1" bitsize="64"/>
+  <reg name="x2" bitsize="64"/>
+  <reg name="x3" bitsize="64"/>
+  <reg name="x4" bitsize="64"/>
+  <reg name="x5" bitsize="64"/>
+  <reg name="x6" bitsize="64"/>
+  <reg name="x7" bitsize="64"/>
+  <reg name="x8" bitsize="64"/>
+  <reg name="x9" bitsize="64"/>
+  <reg name="x10" bitsize="64"/>
+  <reg name="x11" bitsize="64"/>
+  <reg name="x12" bitsize="64"/>
+  <reg name="x13" bitsize="64"/>
+  <reg name="x14" bitsize="64"/>
+  <reg name="x15" bitsize="64"/>
+  <reg name="x16" bitsize="64"/>
+  <reg name="x17" bitsize="64"/>
+  <reg name="x18" bitsize="64"/>
+  <reg name="x19" bitsize="64"/>
+  <reg name="x20" bitsize="64"/>
+  <reg name="x21" bitsize="64"/>
+  <reg name="x22" bitsize="64"/>
+  <reg name="x23" bitsize="64"/>
+  <reg name="x24" bitsize="64"/>
+  <reg name="x25" bitsize="64"/>
+  <reg name="x26" bitsize="64"/>
+  <reg name="x27" bitsize="64"/>
+  <reg name="x28" bitsize="64"/>
+  <reg name="x29" bitsize="64"/>
+  <reg name="x30" bitsize="64"/>
+  <reg name="sp" bitsize="64" type="data_ptr"/>
+
+  <reg name="pc" bitsize="64" type="code_ptr"/>
+  <reg name="cpsr" bitsize="32"/>
+</feature>

target-arm/Makefile.objs

@@ -5,4 +5,4 @@ obj-$(CONFIG_NO_KVM) += kvm-stub.o
 obj-y += translate.o op_helper.o helper.o cpu.o
 obj-y += neon_helper.o iwmmxt_helper.o
 obj-y += gdbstub.o
-obj-$(TARGET_AARCH64) += cpu64.o translate-a64.o
+obj-$(TARGET_AARCH64) += cpu64.o translate-a64.o gdbstub64.o

target-arm/cpu-qom.h

@@ -176,6 +176,8 @@ void arm_gt_vtimer_cb(void *opaque);
 #ifdef TARGET_AARCH64
 void aarch64_cpu_dump_state(CPUState *cs, FILE *f,
                             fprintf_function cpu_fprintf, int flags);
+int aarch64_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
+int aarch64_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
 #endif
 
 #endif

target-arm/cpu64.c

@@ -73,6 +73,10 @@ static void aarch64_cpu_class_init(ObjectClass *oc, void *data)
     CPUClass *cc = CPU_CLASS(oc);
 
     cc->dump_state = aarch64_cpu_dump_state;
+    cc->gdb_read_register = aarch64_cpu_gdb_read_register;
+    cc->gdb_write_register = aarch64_cpu_gdb_write_register;
+    cc->gdb_num_core_regs = 34;
+    cc->gdb_core_xml_file = "aarch64-core.xml";
 }
 
 static void aarch64_cpu_register(const ARMCPUInfo *info)

target-arm/gdbstub64.c

@@ -0,0 +1,73 @@
+/*
+ * ARM gdb server stub: AArch64 specific functions.
+ *
+ * Copyright (c) 2013 SUSE LINUX Products GmbH
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+#include "config.h"
+#include "qemu-common.h"
+#include "exec/gdbstub.h"
+
+int aarch64_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+    CPUARMState *env = &cpu->env;
+
+    if (n < 31) {
+        /* Core integer register.  */
+        return gdb_get_reg64(mem_buf, env->xregs[n]);
+    }
+    switch (n) {
+    case 31:
+        return gdb_get_reg64(mem_buf, env->xregs[31]);
+        break;
+    case 32:
+        return gdb_get_reg64(mem_buf, env->pc);
+        break;
+    case 33:
+        return gdb_get_reg32(mem_buf, env->pstate);
+    }
+    /* Unknown register.  */
+    return 0;
+}
+
+int aarch64_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+    CPUARMState *env = &cpu->env;
+    uint64_t tmp;
+
+    tmp = ldq_p(mem_buf);
+
+    if (n < 31) {
+        /* Core integer register.  */
+        env->xregs[n] = tmp;
+        return 8;
+    }
+    switch (n) {
+    case 31:
+        env->xregs[31] = tmp;
+        return 8;
+    case 32:
+        env->pc = tmp;
+        return 8;
+    case 33:
+        /* CPSR */
+        env->pstate = tmp;
+        return 4;
+    }
+    /* Unknown register.  */
+    return 0;
+}