[Qemu-devel] [PATCH v3 04/12] target-arm: Support fp registers in gdb stub

[Peter Maydell <peter.maydell@linaro.org>]

Register the aarch64-fpu XML and implement the necessary
read/write handlers so we can support reading and writing
of FP registers in the gdb stub.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
---
 configure               |    2 +-
 gdb-xml/aarch64-fpu.xml |   86 +++++++++++++++++++++++++++++++++++++++++++++++
 target-arm/helper.c     |   48 +++++++++++++++++++++++++-
 3 files changed, 134 insertions(+), 2 deletions(-)
 create mode 100644 gdb-xml/aarch64-fpu.xml

diff --git a/configure b/configure
index 3317013..c9ad1de 100755
--- a/configure
+++ b/configure
@@ -4401,7 +4401,7 @@ case "$target_name" in
   aarch64)
     TARGET_BASE_ARCH=arm
     bflt="yes"
-    gdb_xml_files="aarch64-core.xml"
+    gdb_xml_files="aarch64-core.xml aarch64-fpu.xml"
   ;;
   cris)
   ;;
diff --git a/gdb-xml/aarch64-fpu.xml b/gdb-xml/aarch64-fpu.xml
new file mode 100644
index 0000000..997197e
--- /dev/null
+++ b/gdb-xml/aarch64-fpu.xml
@@ -0,0 +1,86 @@
+<?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.fpu">
+  <vector id="v2d" type="ieee_double" count="2"/>
+  <vector id="v2u" type="uint64" count="2"/>
+  <vector id="v2i" type="int64" count="2"/>
+  <vector id="v4f" type="ieee_single" count="4"/>
+  <vector id="v4u" type="uint32" count="4"/>
+  <vector id="v4i" type="int32" count="4"/>
+  <vector id="v8u" type="uint16" count="8"/>
+  <vector id="v8i" type="int16" count="8"/>
+  <vector id="v16u" type="uint8" count="16"/>
+  <vector id="v16i" type="int8" count="16"/>
+  <vector id="v1u" type="uint128" count="1"/>
+  <vector id="v1i" type="int128" count="1"/>
+  <union id="vnd">
+    <field name="f" type="v2d"/>
+    <field name="u" type="v2u"/>
+    <field name="s" type="v2i"/>
+  </union>
+  <union id="vns">
+    <field name="f" type="v4f"/>
+    <field name="u" type="v4u"/>
+    <field name="s" type="v4i"/>
+  </union>
+  <union id="vnh">
+    <field name="u" type="v8u"/>
+    <field name="s" type="v8i"/>
+  </union>
+  <union id="vnb">
+    <field name="u" type="v16u"/>
+    <field name="s" type="v16i"/>
+  </union>
+  <union id="vnq">
+    <field name="u" type="v1u"/>
+    <field name="s" type="v1i"/>
+  </union>
+  <union id="aarch64v">
+    <field name="d" type="vnd"/>
+    <field name="s" type="vns"/>
+    <field name="h" type="vnh"/>
+    <field name="b" type="vnb"/>
+    <field name="q" type="vnq"/>
+  </union>
+  <reg name="v0" bitsize="128" type="aarch64v" regnum="34"/>
+  <reg name="v1" bitsize="128" type="aarch64v" />
+  <reg name="v2" bitsize="128" type="aarch64v" />
+  <reg name="v3" bitsize="128" type="aarch64v" />
+  <reg name="v4" bitsize="128" type="aarch64v" />
+  <reg name="v5" bitsize="128" type="aarch64v" />
+  <reg name="v6" bitsize="128" type="aarch64v" />
+  <reg name="v7" bitsize="128" type="aarch64v" />
+  <reg name="v8" bitsize="128" type="aarch64v" />
+  <reg name="v9" bitsize="128" type="aarch64v" />
+  <reg name="v10" bitsize="128" type="aarch64v"/>
+  <reg name="v11" bitsize="128" type="aarch64v"/>
+  <reg name="v12" bitsize="128" type="aarch64v"/>
+  <reg name="v13" bitsize="128" type="aarch64v"/>
+  <reg name="v14" bitsize="128" type="aarch64v"/>
+  <reg name="v15" bitsize="128" type="aarch64v"/>
+  <reg name="v16" bitsize="128" type="aarch64v"/>
+  <reg name="v17" bitsize="128" type="aarch64v"/>
+  <reg name="v18" bitsize="128" type="aarch64v"/>
+  <reg name="v19" bitsize="128" type="aarch64v"/>
+  <reg name="v20" bitsize="128" type="aarch64v"/>
+  <reg name="v21" bitsize="128" type="aarch64v"/>
+  <reg name="v22" bitsize="128" type="aarch64v"/>
+  <reg name="v23" bitsize="128" type="aarch64v"/>
+  <reg name="v24" bitsize="128" type="aarch64v"/>
+  <reg name="v25" bitsize="128" type="aarch64v"/>
+  <reg name="v26" bitsize="128" type="aarch64v"/>
+  <reg name="v27" bitsize="128" type="aarch64v"/>
+  <reg name="v28" bitsize="128" type="aarch64v"/>
+  <reg name="v29" bitsize="128" type="aarch64v"/>
+  <reg name="v30" bitsize="128" type="aarch64v"/>
+  <reg name="v31" bitsize="128" type="aarch64v"/>
+  <reg name="fpsr" bitsize="32"/>
+  <reg name="fpcr" bitsize="32"/>
+</feature>
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 263dbbf..73c97e8 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -65,6 +65,48 @@ static int vfp_gdb_set_reg(CPUARMState *env, uint8_t *buf, int reg)
     return 0;
 }
 
+static int aarch64_fpu_gdb_get_reg(CPUARMState *env, uint8_t *buf, int reg)
+{
+    switch (reg) {
+    case 0 ... 31:
+        /* 128 bit FP register */
+        stfq_le_p(buf, env->vfp.regs[reg * 2]);
+        stfq_le_p(buf + 8, env->vfp.regs[reg * 2 + 1]);
+        return 16;
+    case 32:
+        /* FPSR */
+        stl_p(buf, vfp_get_fpsr(env));
+        return 4;
+    case 33:
+        /* FPCR */
+        stl_p(buf, vfp_get_fpcr(env));
+        return 4;
+    default:
+        return 0;
+    }
+}
+
+static int aarch64_fpu_gdb_set_reg(CPUARMState *env, uint8_t *buf, int reg)
+{
+    switch (reg) {
+    case 0 ... 31:
+        /* 128 bit FP register */
+        env->vfp.regs[reg * 2] = ldfq_le_p(buf);
+        env->vfp.regs[reg * 2 + 1] = ldfq_le_p(buf + 8);
+        return 16;
+    case 32:
+        /* FPSR */
+        vfp_set_fpsr(env, ldl_p(buf));
+        return 4;
+    case 33:
+        /* FPCR */
+        vfp_set_fpcr(env, ldl_p(buf));
+        return 4;
+    default:
+        return 0;
+    }
+}
+
 static int raw_read(CPUARMState *env, const ARMCPRegInfo *ri,
                     uint64_t *value)
 {
@@ -1785,7 +1827,11 @@ void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
     CPUState *cs = CPU(cpu);
     CPUARMState *env = &cpu->env;
 
-    if (arm_feature(env, ARM_FEATURE_NEON)) {
+    if (arm_feature(env, ARM_FEATURE_AARCH64)) {
+        gdb_register_coprocessor(cs, aarch64_fpu_gdb_get_reg,
+                                 aarch64_fpu_gdb_set_reg,
+                                 34, "aarch64-fpu.xml", 0);
+    } else if (arm_feature(env, ARM_FEATURE_NEON)) {
         gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
                                  51, "arm-neon.xml", 0);
     } else if (arm_feature(env, ARM_FEATURE_VFP3)) {
-- 
1.7.9.5