freebsd-nq/contrib/opencsd/decoder/source/ocsd_code_follower.cpp
2018-04-04 12:55:31 +00:00

162 lines
5.4 KiB
C++

/*
* \file ocsd_code_follower.cpp
* \brief OpenCSD : Instruction Code path follower.
*
* \copyright Copyright (c) 2016, ARM Limited. All Rights Reserved.
*/
/*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "common/ocsd_code_follower.h"
OcsdCodeFollower::OcsdCodeFollower()
{
m_instr_info.pe_type.arch = ARCH_UNKNOWN;
m_instr_info.pe_type.profile = profile_Unknown;
m_instr_info.isa = ocsd_isa_unknown;
m_instr_info.dsb_dmb_waypoints = 0;
m_instr_info.instr_addr = 0;
m_instr_info.opcode = 0;
m_pMemAccess = 0;
m_pIDecode = 0;
m_mem_space_csid = 0;
m_st_range_addr = m_en_range_addr = m_next_addr = 0;
m_b_next_valid = false;
m_b_nacc_err = false;
}
OcsdCodeFollower::~OcsdCodeFollower()
{
}
void OcsdCodeFollower::initInterfaces(componentAttachPt<ITargetMemAccess> *pMemAccess, componentAttachPt<IInstrDecode> *pIDecode)
{
m_pMemAccess = pMemAccess;
m_pIDecode = pIDecode;
}
bool OcsdCodeFollower::initFollowerState()
{
bool initDone = false;
// reset per follow flags
m_b_next_valid = false;
m_b_nacc_err = false;
// set range addresses
m_en_range_addr = m_next_addr = m_st_range_addr;
// check initialisation is valid.
// must have attached memory access and i-decode objects
if(m_pMemAccess && m_pIDecode)
{
initDone = (m_pMemAccess->hasAttachedAndEnabled() && m_pIDecode->hasAttachedAndEnabled());
}
return initDone;
}
/*!
* Decodes an instruction at a single location, calculates the next address
* if possible according to the instruction type and atom.
*
* @param addrStart : Address of the instruction
* @param A : Atom value - E or N
*
* @return ocsd_err_t : OCSD_OK - decode correct, check flags for next address
* : OCSD_ERR_MEM_NACC - unable to access memory area @ address - need new address in trace packet stream.
* : OCSD_ERR_NOT_INIT - not initialised - fatal.
* : OCSD_<other> - other error occured - fatal.
*/
ocsd_err_t OcsdCodeFollower::followSingleAtom(const ocsd_vaddr_t addrStart, const ocsd_atm_val A)
{
ocsd_err_t err = OCSD_ERR_NOT_INIT;
if(!initFollowerState())
return err;
m_en_range_addr = m_st_range_addr = m_instr_info.instr_addr = addrStart;
err = decodeSingleOpCode();
if(err != OCSD_OK)
return err;
// set end range - always after the instruction executed.
m_en_range_addr = m_instr_info.instr_addr + m_instr_info.instr_size;
// assume next addr is the instruction after
m_next_addr = m_en_range_addr;
m_b_next_valid = true;
// case when next address is different
switch(m_instr_info.type)
{
case OCSD_INSTR_BR:
if(A == ATOM_E) // executed the direct branch
m_next_addr = m_instr_info.branch_addr;
break;
case OCSD_INSTR_BR_INDIRECT:
if(A == ATOM_E) // executed indirect branch
m_b_next_valid = false;
break;
}
return err;
}
ocsd_err_t OcsdCodeFollower::decodeSingleOpCode()
{
ocsd_err_t err = OCSD_OK;
// request 4 bytes for the opcode - even for Thumb which may be T32
uint32_t bytesReq = 4;
uint32_t opcode; // buffer for opcode
// read memory location for opcode
err = m_pMemAccess->first()->ReadTargetMemory(m_instr_info.instr_addr,m_mem_space_csid,m_mem_acc_rule,&bytesReq,(uint8_t *)&opcode);
// operational error (not access problem - that is indicated by 0 bytes returned)
if(err != OCSD_OK)
return err;
if(bytesReq == 4) // check that we got all memory requested.
{
m_instr_info.opcode = opcode;
err = m_pIDecode->first()->DecodeInstruction(&m_instr_info);
}
else // otherwise memory unavailable.
{
m_b_nacc_err = true;
m_nacc_address = m_instr_info.instr_addr;
err = OCSD_ERR_MEM_NACC;
}
return err;
}
/* End of File ocsd_code_follower.cpp */