1 //===- MSP430.cpp ---------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // The MSP430 is a 16-bit microcontroller RISC architecture. The instruction set 10 // has only 27 core instructions orthogonally augmented with a variety 11 // of addressing modes for source and destination operands. Entire address space 12 // of MSP430 is 64KB (the extended MSP430X architecture is not considered here). 13 // A typical MSP430 MCU has several kilobytes of RAM and ROM, plenty 14 // of peripherals and is generally optimized for a low power consumption. 15 // 16 //===----------------------------------------------------------------------===// 17 18 #include "InputFiles.h" 19 #include "Symbols.h" 20 #include "Target.h" 21 #include "lld/Common/ErrorHandler.h" 22 #include "llvm/Object/ELF.h" 23 #include "llvm/Support/Endian.h" 24 25 using namespace llvm; 26 using namespace llvm::object; 27 using namespace llvm::support::endian; 28 using namespace llvm::ELF; 29 30 namespace lld { 31 namespace elf { 32 33 namespace { 34 class MSP430 final : public TargetInfo { 35 public: 36 MSP430(); 37 RelExpr getRelExpr(RelType type, const Symbol &s, 38 const uint8_t *loc) const override; 39 void relocate(uint8_t *loc, const Relocation &rel, 40 uint64_t val) const override; 41 }; 42 } // namespace 43 44 MSP430::MSP430() { 45 // mov.b #0, r3 46 trapInstr = {0x43, 0x43, 0x43, 0x43}; 47 } 48 49 RelExpr MSP430::getRelExpr(RelType type, const Symbol &s, 50 const uint8_t *loc) const { 51 switch (type) { 52 case R_MSP430_10_PCREL: 53 case R_MSP430_16_PCREL: 54 case R_MSP430_16_PCREL_BYTE: 55 case R_MSP430_2X_PCREL: 56 case R_MSP430_RL_PCREL: 57 case R_MSP430_SYM_DIFF: 58 return R_PC; 59 default: 60 return R_ABS; 61 } 62 } 63 64 void MSP430::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const { 65 switch (rel.type) { 66 case R_MSP430_8: 67 checkIntUInt(loc, val, 8, rel); 68 *loc = val; 69 break; 70 case R_MSP430_16: 71 case R_MSP430_16_PCREL: 72 case R_MSP430_16_BYTE: 73 case R_MSP430_16_PCREL_BYTE: 74 checkIntUInt(loc, val, 16, rel); 75 write16le(loc, val); 76 break; 77 case R_MSP430_32: 78 checkIntUInt(loc, val, 32, rel); 79 write32le(loc, val); 80 break; 81 case R_MSP430_10_PCREL: { 82 int16_t offset = ((int16_t)val >> 1) - 1; 83 checkInt(loc, offset, 10, rel); 84 write16le(loc, (read16le(loc) & 0xFC00) | (offset & 0x3FF)); 85 break; 86 } 87 default: 88 error(getErrorLocation(loc) + "unrecognized relocation " + 89 toString(rel.type)); 90 } 91 } 92 93 TargetInfo *getMSP430TargetInfo() { 94 static MSP430 target; 95 return ⌖ 96 } 97 98 } // namespace elf 99 } // namespace lld 100