diff options
| author | 2013-02-08 11:30:38 -0800 | |
|---|---|---|
| committer | 2013-02-08 11:30:38 -0800 | |
| commit | d0876a9b6d1b58409f642c3886cabb42bcd0ae09 (patch) | |
| tree | 1a3ca210f7a6682513dad3efaca9f0af9fac95df | |
| parent | 550191374245cc43089c916a34b292cc4e617daf (diff) | |
Thumb32 form branch disassembly.
Change-Id: I3a1af9164047b2d4ee1e215909e287be05a38bde
| -rw-r--r-- | src/disassembler_arm.cc | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/src/disassembler_arm.cc b/src/disassembler_arm.cc index ae090a1801..9a5ca75bac 100644 --- a/src/disassembler_arm.cc +++ b/src/disassembler_arm.cc @@ -708,8 +708,47 @@ size_t DisassemblerArm::DumpThumb32(std::ostream& os, const uint8_t* instr_ptr) } break; case 2: - case 1: case 3: + if ((op2 & 0x38) == 0x38) { + if (op2 == 0x7F) { + opcode << "udf"; + } + break; + } + // Else deliberate fall-through to B. + case 1: case 3: { + // B + // |111|11|1|0000|000000|11|1 |1|1 |10000000000| + // |5 3|21|0|9876|543 0|54|3 |2|1 |0 5 0| + // |---|--|-|----|------|--|--|-|--|-----------| + // |332|22|2|2222|221111|11|1 |1|1 |10000000000| + // |1 9|87|6|5 2|10 6|54|3 |2|1 |0 5 0| + // |---|--|-|----|------|--|--|-|--|-----------| + // |111|10|S|cond| imm6 |10|J1|0|J2| imm11 | + // |111|10|S| imm10 |10|J1|1|J2| imm11 | + uint32_t S = (instr >> 26) & 1; + uint32_t cond = (instr >> 22) & 0xF; + uint32_t J2 = (instr >> 11) & 1; + uint32_t form = (instr >> 12) & 1; + uint32_t J1 = (instr >> 13) & 1; + uint32_t imm10 = (instr >> 16) & 0x3FF; + uint32_t imm6 = (instr >> 16) & 0x3F; + uint32_t imm11 = instr & 0x7FF; + opcode << "b"; + int32_t imm32; + if (form == 0) { + DumpCond(opcode, cond); + imm32 = (S << 20) | (J2 << 19) | (J1 << 18) | (imm6 << 12) | (imm11 << 1); + imm32 = (imm32 << 11) >> 11; // sign extend 21 bit immediate. + } else { + uint32_t I1 = ~(J1 ^ S); + uint32_t I2 = ~(J2 ^ S); + imm32 = (S << 24) | (I1 << 23) | (I2 << 22) | (imm10 << 12) | (imm11 << 1); + imm32 = (imm32 << 8) >> 8; // sign extend 24 bit immediate. + } + opcode << ".w"; + DumpBranchTarget(args, instr_ptr + 4, imm32); break; + } case 4: case 6: case 5: case 7: { // BL, BLX (immediate) // |111|11|1|0000000000|11|1 |1|1 |10000000000| |