diff options
Diffstat (limited to 'decoders/arm_tpiu')
| -rw-r--r-- | decoders/arm_tpiu/__init__.py | 28 | ||||
| -rw-r--r-- | decoders/arm_tpiu/pd.py | 128 |
2 files changed, 156 insertions, 0 deletions
diff --git a/decoders/arm_tpiu/__init__.py b/decoders/arm_tpiu/__init__.py new file mode 100644 index 0000000..4958df8 --- /dev/null +++ b/decoders/arm_tpiu/__init__.py @@ -0,0 +1,28 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2015 Petteri Aimonen <jpa@sigrok.mail.kapsi.fi> +## +## This program is free software; you can redistribute it and/or modify +## it under the terms of the GNU General Public License as published by +## the Free Software Foundation; either version 2 of the License, or +## (at your option) any later version. +## +## This program is distributed in the hope that it will be useful, +## but WITHOUT ANY WARRANTY; without even the implied warranty of +## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +## GNU General Public License for more details. +## +## You should have received a copy of the GNU General Public License +## along with this program; if not, write to the Free Software +## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +## + +''' +This decoder stacks on top of the 'uart' decoder and decodes the frame format +of ARMv7m Trace Port Interface Unit. It filters the data coming from various +trace sources (such as ARMv7m ITM and ETM blocks) into separate streams that +can be further decoded by other PDs. +''' + +from .pd import Decoder diff --git a/decoders/arm_tpiu/pd.py b/decoders/arm_tpiu/pd.py new file mode 100644 index 0000000..0e07eb4 --- /dev/null +++ b/decoders/arm_tpiu/pd.py @@ -0,0 +1,128 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2015 Petteri Aimonen <jpa@sigrok.mail.kapsi.fi> +## +## This program is free software; you can redistribute it and/or modify +## it under the terms of the GNU General Public License as published by +## the Free Software Foundation; either version 2 of the License, or +## (at your option) any later version. +## +## This program is distributed in the hope that it will be useful, +## but WITHOUT ANY WARRANTY; without even the implied warranty of +## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +## GNU General Public License for more details. +## +## You should have received a copy of the GNU General Public License +## along with this program; if not, write to the Free Software +## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +## + +import sigrokdecode as srd + +class Decoder(srd.Decoder): + api_version = 2 + id = 'arm_tpiu' + name = 'ARM TPIU' + longname = 'ARM Trace Port Interface Unit' + desc = 'Filter TPIU formatted trace data into separate data streams.' + license = 'gplv2+' + inputs = ['uart'] + outputs = ['uart'] # Emulate uart output so that arm_itm/arm_etm can stack. + options = ( + {'id': 'stream', 'desc': 'Stream index', 'default': 1}, + {'id': 'sync_offset', 'desc': 'Initial sync offset', 'default': 0}, + ) + annotations = ( + ('stream', 'Current stream'), + ('data', 'Stream data'), + ) + annotation_rows = ( + ('stream', 'Current stream', (0,)), + ('data', 'Stream data', (1,)), + ) + + def __init__(self, **kwargs): + self.buf = [] + self.syncbuf = [] + self.prevsample = 0 + self.stream = 0 + self.stream_ss = None + self.bytenum = 0 + + def start(self): + self.out_ann = self.register(srd.OUTPUT_ANN) + self.out_python = self.register(srd.OUTPUT_PYTHON) + + def stream_changed(self, ss, stream): + if self.stream != stream: + if self.stream != 0: + self.put(self.stream_ss, ss, self.out_ann, + [0, ["Stream %d" % self.stream, "S%d" % self.stream]]) + self.stream = stream + self.stream_ss = ss + + def emit_byte(self, ss, es, byte): + if self.stream == self.options['stream']: + self.put(ss, es, self.out_ann, [1, ["0x%02x" % byte]]) + self.put(ss, es, self.out_python, ['DATA', 0, (byte, [])]) + + def process_frame(self, buf): + # Byte 15 contains the lowest bits of bytes 0, 2, ... 14. + lowbits = buf[15][2] + + for i in range(0, 15, 2): + # Odd bytes can be stream ID or data. + delayed_stream_change = None + lowbit = (lowbits >> (i // 2)) & 0x01 + if buf[i][2] & 0x01 != 0: + if lowbit: + delayed_stream_change = buf[i][2] >> 1 + else: + self.stream_changed(buf[i][0], buf[i][2] >> 1) + else: + byte = buf[i][2] | lowbit + self.emit_byte(buf[i][0], buf[i][1], byte) + + # Even bytes are always data. + if i < 14: + self.emit_byte(buf[i+1][0], buf[i+1][1], buf[i+1][2]) + + # The stream change can be delayed to occur after the data byte. + if delayed_stream_change is not None: + self.stream_changed(buf[i+1][1], delayed_stream_change) + + def decode(self, ss, es, data): + ptype, rxtx, pdata = data + + if ptype != 'DATA': + return + + # Reset packet if there is a long pause between bytes. + self.byte_len = es - ss + if ss - self.prevsample > self.byte_len: + self.buf = [] + self.prevsample = es + + self.buf.append((ss, es, pdata[0])) + self.bytenum += 1 + + # Allow skipping N first bytes of the data. By adjusting the sync + # value, one can get initial synchronization as soon as the trace + # starts. + if self.bytenum < self.options['sync_offset']: + self.buf = [] + return + + # Keep separate buffer for detection of sync packets. + # Sync packets override everything else, so that we can regain sync + # even if some packets are corrupted. + self.syncbuf = self.syncbuf[-3:] + [pdata[0]] + if self.syncbuf == [0xFF, 0xFF, 0xFF, 0x7F]: + self.buf = [] + self.syncbuf = [] + return + + if len(self.buf) == 16: + self.process_frame(self.buf) + self.buf = [] |