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Diffstat (limited to 'decoder/source/ocsd_code_follower.cpp')
| -rw-r--r-- | decoder/source/ocsd_code_follower.cpp | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/decoder/source/ocsd_code_follower.cpp b/decoder/source/ocsd_code_follower.cpp new file mode 100644 index 0000000..4386eb4 --- /dev/null +++ b/decoder/source/ocsd_code_follower.cpp @@ -0,0 +1,162 @@ +/* + * \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.wfi_wfe_branch = 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 */ |