From 4ddeceba96c5e066d79138709091a6dffec17372 Mon Sep 17 00:00:00 2001
From: Gabe Black <gblack@eecs.umich.edu>
Date: Wed, 2 Jun 2010 12:58:00 -0500
Subject: [PATCH] ARM: Allow ARM processes to start in Thumb mode.

---
 src/arch/arm/linux/process.cc | 4 ++--
 src/arch/arm/linux/process.hh | 3 ++-
 src/arch/arm/process.cc       | 7 +++++--
 src/arch/arm/process.hh       | 5 ++++-
 src/sim/process.cc            | 5 +----
 5 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/src/arch/arm/linux/process.cc b/src/arch/arm/linux/process.cc
index f909d871a..7a5e9da56 100644
--- a/src/arch/arm/linux/process.cc
+++ b/src/arch/arm/linux/process.cc
@@ -435,8 +435,8 @@ SyscallDesc ArmLinuxProcess::privSyscallDescs[] = {
 };
 
 ArmLinuxProcess::ArmLinuxProcess(LiveProcessParams * params,
-        ObjectFile *objFile)
-    : ArmLiveProcess(params, objFile),
+        ObjectFile *objFile, ObjectFile::Arch _arch)
+    : ArmLiveProcess(params, objFile, _arch),
      Num_Syscall_Descs(sizeof(syscallDescs) / sizeof(SyscallDesc)),
      Num_Priv_Syscall_Descs(sizeof(privSyscallDescs) / sizeof(SyscallDesc))
 { }
diff --git a/src/arch/arm/linux/process.hh b/src/arch/arm/linux/process.hh
index ab836fab2..7b9e5789e 100644
--- a/src/arch/arm/linux/process.hh
+++ b/src/arch/arm/linux/process.hh
@@ -38,7 +38,8 @@
 class ArmLinuxProcess : public ArmLiveProcess
 {
   public:
-    ArmLinuxProcess(LiveProcessParams * params, ObjectFile *objFile);
+    ArmLinuxProcess(LiveProcessParams * params, ObjectFile *objFile,
+                    ObjectFile::Arch _arch);
 
     virtual SyscallDesc* getDesc(int callnum);
 
diff --git a/src/arch/arm/process.cc b/src/arch/arm/process.cc
index 702922a43..3c51c80a7 100644
--- a/src/arch/arm/process.cc
+++ b/src/arch/arm/process.cc
@@ -43,8 +43,9 @@
 using namespace std;
 using namespace ArmISA;
 
-ArmLiveProcess::ArmLiveProcess(LiveProcessParams *params, ObjectFile *objFile)
-    : LiveProcess(params, objFile)
+ArmLiveProcess::ArmLiveProcess(LiveProcessParams *params, ObjectFile *objFile,
+                               ObjectFile::Arch _arch)
+    : LiveProcess(params, objFile), arch(_arch)
 {
     stack_base = 0xbf000000L;
 
@@ -316,6 +317,8 @@ ArmLiveProcess::argsInit(int intSize, int pageSize)
     }
 
     Addr prog_entry = objFile->entryPoint();
+    if (arch == ObjectFile::Thumb)
+        prog_entry = (prog_entry & ~mask(1)) | (ULL(1) << PcTBitShift);
     tc->setPC(prog_entry);
     tc->setNextPC(prog_entry + sizeof(MachInst));
 
diff --git a/src/arch/arm/process.hh b/src/arch/arm/process.hh
index f793892d0..a4dd5e842 100644
--- a/src/arch/arm/process.hh
+++ b/src/arch/arm/process.hh
@@ -33,6 +33,7 @@
 
 #include <string>
 #include <vector>
+#include "base/loader/object_file.hh"
 #include "sim/process.hh"
 
 class LiveProcess;
@@ -42,7 +43,9 @@ class System;
 class ArmLiveProcess : public LiveProcess
 {
   protected:
-    ArmLiveProcess(LiveProcessParams * params, ObjectFile *objFile);
+    ObjectFile::Arch arch;
+    ArmLiveProcess(LiveProcessParams * params, ObjectFile *objFile,
+                   ObjectFile::Arch _arch);
 
     void startup();
 
diff --git a/src/sim/process.cc b/src/sim/process.cc
index 18f33abdc..ba4a3905b 100644
--- a/src/sim/process.cc
+++ b/src/sim/process.cc
@@ -763,10 +763,7 @@ LiveProcess::create(LiveProcessParams * params)
         warn("Unknown operating system; assuming Linux.");
         // fall through
       case ObjectFile::Linux:
-        if (objFile->getArch() == ObjectFile::Thumb)
-            panic("Thumb processes not yet supported.\n");
-        else
-            process = new ArmLinuxProcess(params, objFile);
+        process = new ArmLinuxProcess(params, objFile, objFile->getArch());
         break;
       case ObjectFile::LinuxArmOABI:
         fatal("M5 does not support ARM OABI binaries. Please recompile with an"