1//===-- RegisterContextFreeBSDKernel_arm64.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#include "RegisterContextFreeBSDKernel_arm64.h"
10#include "Plugins/Process/Utility/lldb-arm64-register-enums.h"
11
12#include "lldb/Target/Process.h"
13#include "lldb/Target/Thread.h"
14#include "lldb/Utility/RegisterValue.h"
15#include "llvm/Support/Endian.h"
16
17using namespace lldb;
18using namespace lldb_private;
19
20RegisterContextFreeBSDKernel_arm64::RegisterContextFreeBSDKernel_arm64(
21    Thread &thread, std::unique_ptr<RegisterInfoPOSIX_arm64> register_info_up,
22    lldb::addr_t pcb_addr)
23    : RegisterContextPOSIX_arm64(thread, std::move(register_info_up)),
24      m_pcb_addr(pcb_addr) {}
25
26bool RegisterContextFreeBSDKernel_arm64::ReadGPR() { return true; }
27
28bool RegisterContextFreeBSDKernel_arm64::ReadFPR() { return true; }
29
30bool RegisterContextFreeBSDKernel_arm64::WriteGPR() {
31  assert(0);
32  return false;
33}
34
35bool RegisterContextFreeBSDKernel_arm64::WriteFPR() {
36  assert(0);
37  return false;
38}
39
40bool RegisterContextFreeBSDKernel_arm64::ReadRegister(
41    const RegisterInfo *reg_info, RegisterValue &value) {
42  if (m_pcb_addr == LLDB_INVALID_ADDRESS)
43    return false;
44
45  struct {
46    llvm::support::ulittle64_t x[30];
47    llvm::support::ulittle64_t lr;
48    llvm::support::ulittle64_t _reserved;
49    llvm::support::ulittle64_t sp;
50  } pcb;
51
52  Status error;
53  size_t rd =
54      m_thread.GetProcess()->ReadMemory(m_pcb_addr, &pcb, sizeof(pcb), error);
55  if (rd != sizeof(pcb))
56    return false;
57
58  uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
59  switch (reg) {
60  case gpr_x0_arm64:
61  case gpr_x1_arm64:
62  case gpr_x2_arm64:
63  case gpr_x3_arm64:
64  case gpr_x4_arm64:
65  case gpr_x5_arm64:
66  case gpr_x6_arm64:
67  case gpr_x7_arm64:
68  case gpr_x8_arm64:
69  case gpr_x9_arm64:
70  case gpr_x10_arm64:
71  case gpr_x11_arm64:
72  case gpr_x12_arm64:
73  case gpr_x13_arm64:
74  case gpr_x14_arm64:
75  case gpr_x15_arm64:
76  case gpr_x16_arm64:
77  case gpr_x17_arm64:
78  case gpr_x18_arm64:
79  case gpr_x19_arm64:
80  case gpr_x20_arm64:
81  case gpr_x21_arm64:
82  case gpr_x22_arm64:
83  case gpr_x23_arm64:
84  case gpr_x24_arm64:
85  case gpr_x25_arm64:
86  case gpr_x26_arm64:
87  case gpr_x27_arm64:
88  case gpr_x28_arm64:
89  case gpr_fp_arm64:
90    static_assert(gpr_fp_arm64 - gpr_x0_arm64 == 29,
91                  "nonconsecutive arm64 register numbers");
92    value = pcb.x[reg - gpr_x0_arm64];
93    break;
94  case gpr_sp_arm64:
95    value = pcb.sp;
96    break;
97  case gpr_pc_arm64:
98    // The pc of crashing thread is stored in lr.
99    value = pcb.lr;
100    break;
101  default:
102    return false;
103  }
104  return true;
105}
106
107bool RegisterContextFreeBSDKernel_arm64::WriteRegister(
108    const RegisterInfo *reg_info, const RegisterValue &value) {
109  return false;
110}
111