Add eContextRegisterLoad instruction emulation context.
Add code to emulate STR (Immediate, Thumb) instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@125610 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/lldb/Core/EmulateInstruction.h b/include/lldb/Core/EmulateInstruction.h
index 6175d61..917c6d7 100644
--- a/include/lldb/Core/EmulateInstruction.h
+++ b/include/lldb/Core/EmulateInstruction.h
@@ -133,6 +133,8 @@
// arg2 = address of store
eContextRegisterStore,
+ eContextRegisterLoad,
+
// Used when performing a PC-relative branch where the
// arg0 = don't care
// arg1 = imm32 (signed offset)
diff --git a/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp b/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp
index b604592..1797bc1 100644
--- a/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp
+++ b/source/Plugins/Instruction/ARM/EmulateInstructionARM.cpp
@@ -3396,7 +3396,169 @@
}
return true;
}
+
+// STR (store immediate) calcualtes an address from a base register value and an immediate offset, and stores a word
+// from a register to memory. It can use offset, post-indexed, or pre-indexed addressing.
+bool
+EmulateInstructionARM::EmulateSTRThumb (ARMEncoding encoding)
+{
+#if 0
+ if ConditionPassed() then
+ EncodingSpecificOperations(); NullCheckIfThumbEE(n);
+ offset_addr = if add then (R[n] + imm32) else (R[n] - imm32);
+ address = if index then offset_addr else R[n];
+ if UnalignedSupport() || address<1:0> == ’00’ then
+ MemU[address,4] = R[t];
+ else // Can only occur before ARMv7
+ MemU[address,4] = bits(32) UNKNOWN;
+ if wback then R[n] = offset_addr;
+#endif
+ bool success = false;
+ const uint32_t opcode = OpcodeAsUnsigned (&success);
+ if (!success)
+ return false;
+
+ if (ConditionPassed())
+ {
+ const uint32_t addr_byte_size = GetAddressByteSize();
+
+ uint32_t t;
+ uint32_t n;
+ uint32_t imm32;
+ bool index;
+ bool add;
+ bool wback;
+ // EncodingSpecificOperations (); NullCheckIfThumbEE(n);
+ switch (encoding)
+ {
+ case eEncodingT1:
+ // t = UInt(Rt); n = UInt(Rn); imm32 = ZeroExtend(imm5:’00’, 32);
+ t = Bits32 (opcode, 2, 0);
+ n = Bits32 (opcode, 5, 3);
+ imm32 = Bits32 (opcode, 10, 6) << 2;
+
+ // index = TRUE; add = TRUE; wback = FALSE;
+ index = true;
+ add = false;
+ wback = false;
+ break;
+
+ case eEncodingT2:
+ // t = UInt(Rt); n = 13; imm32 = ZeroExtend(imm8:’00’, 32);
+ t = Bits32 (opcode, 10, 8);
+ n = 13;
+ imm32 = Bits32 (opcode, 7, 0) << 2;
+
+ // index = TRUE; add = TRUE; wback = FALSE;
+ index = true;
+ add = true;
+ wback = false;
+ break;
+
+ case eEncodingT3:
+ // if Rn == ’1111’ then UNDEFINED;
+ if (Bits32 (opcode, 19, 16) == 15)
+ return false;
+
+ // t = UInt(Rt); n = UInt(Rn); imm32 = ZeroExtend(imm12, 32);
+ t = Bits32 (opcode, 15, 12);
+ n = Bits32 (opcode, 19, 16);
+ imm32 = Bits32 (opcode, 11, 0);
+
+ // index = TRUE; add = TRUE; wback = FALSE;
+ index = true;
+ add = true;
+ wback = false;
+
+ // if t == 15 then UNPREDICTABLE;
+ if (t == 15)
+ return false;
+ break;
+
+ case eEncodingT4:
+ // if P == ’1’ && U == ’1’ && W == ’0’ then SEE STRT;
+ // if Rn == ’1101’ && P == ’1’ && U == ’0’ && W == ’1’ && imm8 == ’00000100’ then SEE PUSH;
+ // if Rn == ’1111’ || (P == ’0’ && W == ’0’) then UNDEFINED;
+ if ((Bits32 (opcode, 19, 16) == 15)
+ || (BitIsClear (opcode, 10) && BitIsClear (opcode, 8)))
+ return false;
+
+ // t = UInt(Rt); n = UInt(Rn); imm32 = ZeroExtend(imm8, 32);
+ t = Bits32 (opcode, 15, 12);
+ n = Bits32 (opcode, 19, 16);
+ imm32 = Bits32 (opcode, 7, 0);
+
+ // index = (P == ’1’); add = (U == ’1’); wback = (W == ’1’);
+ index = BitIsSet (opcode, 10);
+ add = BitIsSet (opcode, 9);
+ wback = BitIsSet (opcode, 8);
+
+ // if t == 15 || (wback && n == t) then UNPREDICTABLE;
+ if ((t == 15) || (wback && (n == t)))
+ return false;
+ break;
+
+ default:
+ return false;
+ }
+
+ addr_t offset_addr;
+ addr_t address;
+
+ // offset_addr = if add then (R[n] + imm32) else (R[n] - imm32);
+ uint32_t base_address = ReadRegisterUnsigned (eRegisterKindDWARF, dwarf_r0 + n, 0, &success);
+ if (!success)
+ return false;
+
+ if (add)
+ offset_addr = base_address + imm32;
+ else
+ offset_addr = base_address - imm32;
+
+ // address = if index then offset_addr else R[n];
+ if (index)
+ address = offset_addr;
+ else
+ address = base_address;
+
+ EmulateInstruction::Context context;
+ context.type = eContextRegisterStore;
+ Register base_reg;
+ base_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + n);
+
+ // if UnalignedSupport() || address<1:0> == ’00’ then
+ if (UnalignedSupport () || (BitIsClear (address, 1) && BitIsClear (address, 0)))
+ {
+ // MemU[address,4] = R[t];
+ uint32_t data = ReadRegisterUnsigned (eRegisterKindDWARF, dwarf_r0 + t, 0, &success);
+ if (!success)
+ return false;
+
+ Register data_reg;
+ data_reg.SetRegister (eRegisterKindDWARF, dwarf_r0 + t);
+ int32_t offset = address - base_address;
+ context.SetRegisterToRegisterPlusOffset (data_reg, base_reg, offset);
+ if (!WriteMemoryUnsigned (context, address, data, addr_byte_size))
+ return false;
+ }
+ else
+ {
+ // MemU[address,4] = bits(32) UNKNOWN;
+ WriteBits32UnknownToMemory (address);
+ }
+
+ // if wback then R[n] = offset_addr;
+ if (wback)
+ {
+ context.type = eContextRegisterLoad;
+ context.SetAddress (offset_addr);
+ if (!WriteRegisterUnsigned (context, eRegisterKindDWARF, dwarf_r0 + n, offset_addr))
+ return false;
+ }
+ }
+ return true;
+}
EmulateInstructionARM::ARMOpcode*
EmulateInstructionARM::GetARMOpcodeForInstruction (const uint32_t opcode)
@@ -3607,8 +3769,11 @@
//----------------------------------------------------------------------
{ 0xfffff800, 0x0000c000, ARMV4T_ABOVE, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateSTM, "stm<c> <Rn>{!} <registers>" },
{ 0xffd00000, 0xe8800000, ARMV6T2_ABOVE, eEncodingT2, eSize32, &EmulateInstructionARM::EmulateSTM, "stm<c>.w <Rn>{!} <registers>" },
- { 0xffd00000, 0xe9000000, ARMV6T2_ABOVE, eEncodingT1, eSize32, &EmulateInstructionARM::EmulateSTMDB, "stmdb<c> <Rn>{!} <registers>" }
-
+ { 0xffd00000, 0xe9000000, ARMV6T2_ABOVE, eEncodingT1, eSize32, &EmulateInstructionARM::EmulateSTMDB, "stmdb<c> <Rn>{!} <registers>" },
+ { 0xfffff800, 0x00006000, ARMV4T_ABOVE, eEncodingT1, eSize16, &EmulateInstructionARM::EmulateSTRThumb, "str<c> <Rt> [<Rn>{,#<imm>}]" },
+ { 0xfffff800, 0x00009000, ARMV4T_ABOVE, eEncodingT2, eSize16, &EmulateInstructionARM::EmulateSTRThumb, "str<c> <Rt> [SP,#<imm>]" },
+ { 0xfff00000, 0xf8c00000, ARMV6T2_ABOVE, eEncodingT3, eSize32, &EmulateInstructionARM::EmulateSTRThumb, "str<c>.w <Rt [<Rn>,#<imm12>]" },
+ { 0xfff00800, 0xf8400800, ARMV6T2_ABOVE, eEncodingT4, eSize32, &EmulateInstructionARM::EmulateSTRThumb, "str<c> <Rt> [<Rn>,#+/-<imm8>]" }
};
const size_t k_num_thumb_opcodes = sizeof(g_thumb_opcodes)/sizeof(ARMOpcode);
diff --git a/source/Plugins/Instruction/ARM/EmulateInstructionARM.h b/source/Plugins/Instruction/ARM/EmulateInstructionARM.h
index 6a6105d..7ea8725 100644
--- a/source/Plugins/Instruction/ARM/EmulateInstructionARM.h
+++ b/source/Plugins/Instruction/ARM/EmulateInstructionARM.h
@@ -335,6 +335,9 @@
bool
EmulateSTMIB (ARMEncoding encoding);
+ bool
+ EmulateSTRThumb(ARMEncoding encoding);
+
uint32_t m_arm_isa;
Mode m_inst_mode;
uint32_t m_inst_cpsr;