src/developer/debug/debug_agent/arch_arm64_helpers.h

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#pragma once

#include <zircon/syscalls/exception.h>
#include <lib/zx/thread.h>

#include "src/developer/debug/debug_agent/arch_arm64.h"
#include "src/developer/debug/ipc/protocol.h"

namespace debug_agent {
namespace arch {

// The ESR register holds information about the last exception in the form of:
// |31      26|25|24                              0|
// |    EC    |IL|             ISS                 |
//
// Where:
// - EC: Exception class field (what exception ocurred).
// - IL: Instruction length (whether the trap was 16-bit of 32-bit instruction).
// - ISS: Instruction Specific Syndrome. The value is specific to each EC.
inline uint32_t Arm64ExtractECFromESR(uint32_t esr) { return esr >> 26; }

// Helpers for defining arm64 specific behavior.

// Fills the given state the debug registers to what it should be if we added
// an execution HW breakpoint for |address|.
// Return ZX_ERR_NO_RESOURCES if there are no registers left.
zx_status_t SetupHWBreakpoint(uint64_t address, zx_thread_state_debug_regs_t*);

// Removes an installed execution HW breakpoint for |address|.
// If the address is not installed, no functional change will happen and
// ZX_ERR_OUT_OF_RANGE will be returned.
zx_status_t RemoveHWBreakpoint(uint64_t address, zx_thread_state_debug_regs_t*);

// Decodes the ESR provided by zircon for this exception.
debug_ipc::NotifyException::Type DecodeESR(uint32_t esr);

// Useful function for debugging to keep around.
std::string DebugRegistersToString(const zx_thread_state_debug_regs_t&);

}  // namespace arch
}  // namespace debug_agent