disas: Implement disassembly output for A64

Use libvixl to implement disassembly output in debug
logs for A64, for use with both AArch64 hosts and targets.

Signed-off-by: Claudio Fontana <claudio.fontana@linaro.org>
[PMM:
 * added support for target disassembly
 * switched to custom QEMUDisassembler so the output format
   matches what QEMU expects
 * make sure we correctly fall back to "just print hex"
   if we didn't build the AArch64 disassembler because of
   lack of a C++ compiler
 * rename from 'aarch64' to 'arm-a64' because this is a
   disassembler for the A64 instruction set
 * merge aarch64.c and aarch64-cxx.cc into one C++ file
 * simplify the aarch64.c<->aarch64-cxx.cc interface]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 12 insertions, 2 deletions

diff --git a/disas.c b/disas.c
index 0203ef2..79e6944 100644
--- a/disas.c
+++ b/disas.c
@@ -190,7 +190,7 @@ static int print_insn_od_target(bfd_vma pc, disassemble_info *info)
 /* Disassemble this for me please... (debugging). 'flags' has the following
    values:
     i386 - 1 means 16 bit code, 2 means 64 bit code
-    arm  - bit 0 = thumb, bit 1 = reverse endian
+    arm  - bit 0 = thumb, bit 1 = reverse endian, bit 2 = A64
     ppc  - nonzero means little endian
     other targets - unused
  */
@@ -225,7 +225,15 @@ void target_disas(FILE *out, CPUArchState *env, target_ulong code,
     }
     print_insn = print_insn_i386;
 #elif defined(TARGET_ARM)
-    if (flags & 1) {
+    if (flags & 4) {
+        /* We might not be compiled with the A64 disassembler
+         * because it needs a C++ compiler; in that case we will
+         * fall through to the default print_insn_od case.
+         */
+#if defined(CONFIG_ARM_A64_DIS)
+        print_insn = print_insn_arm_a64;
+#endif
+    } else if (flags & 1) {
         print_insn = print_insn_thumb1;
     } else {
         print_insn = print_insn_arm;
@@ -356,6 +364,8 @@ void disas(FILE *out, void *code, unsigned long size)
 #elif defined(_ARCH_PPC)
     s.info.disassembler_options = (char *)"any";
     print_insn = print_insn_ppc;
+#elif defined(__aarch64__) && defined(CONFIG_ARM_A64_DIS)
+    print_insn = print_insn_arm_a64;
 #elif defined(__alpha__)
     print_insn = print_insn_alpha;
 #elif defined(__sparc__)