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Diffstat (limited to 'host/lib/transport/gen_vrt.py')
| -rwxr-xr-x | host/lib/transport/gen_vrt.py | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/host/lib/transport/gen_vrt.py b/host/lib/transport/gen_vrt.py new file mode 100755 index 000000000..918de3ad7 --- /dev/null +++ b/host/lib/transport/gen_vrt.py @@ -0,0 +1,206 @@ +#!/usr/bin/env python +# +# Copyright 2010 Ettus Research LLC +# +# 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 3 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, see <http://www.gnu.org/licenses/>. +# + +""" +The vrt packer/unpacker code generator: + +This script will generate the pack and unpack routines that convert +metatdata into vrt headers and vrt headers into metadata. + +The generated code infers jump tables to speed-up the parsing time. +""" + +TMPL_TEXT = """ +#import time + +######################################################################## +## setup predicates +######################################################################## +#set $sid_p = 0b00001 +#set $cid_p = 0b00010 +#set $tsi_p = 0b00100 +#set $tsf_p = 0b01000 +#set $tlr_p = 0b10000 + +/*********************************************************************** + * This file was generated by $file on $time.strftime("%c") + **********************************************************************/ + +\#include <uhd/transport/vrt.hpp> +\#include <boost/asio.hpp> //endianness conversion +\#include <stdexcept> + +using namespace uhd; +using namespace uhd::transport; + +void vrt::pack( + const tx_metadata_t &metadata, //input + boost::uint32_t *header_buff, //output + size_t &num_header_words32, //output + size_t num_payload_words32, //input + size_t &num_packet_words32, //output + size_t packet_count //input +){ + boost::uint32_t vrt_hdr_flags; + + boost::uint8_t pred = 0; + if (metadata.has_stream_id) pred |= $hex($sid_p); + if (metadata.has_time_spec) pred |= $hex($tsi_p | $tsf_p); + + switch(pred){ + #for $pred in range(2**5) + case $pred: + #set $num_header_words = 1 + #set $flags = 0 + ########## Stream ID ########## + #if $pred & $sid_p + header_buff[$num_header_words] = htonl(metadata.stream_id); + #set $num_header_words += 1 + #set $flags |= (0x1 << 28); + #end if + ########## Class ID ########## + #if $pred & $cid_p + header_buff[$num_header_words] = htonl(0); + #set $num_header_words += 1 + header_buff[$num_header_words] = htonl(0); + #set $num_header_words += 1 + #set $flags |= (0x1 << 27); + #end if + ########## Integer Time ########## + #if $pred & $tsi_p + header_buff[$num_header_words] = htonl(metadata.time_spec.secs); + #set $num_header_words += 1 + #set $flags |= (0x3 << 22); + #end if + ########## Fractional Time ########## + #if $pred & $tsf_p + header_buff[$num_header_words] = htonl(0); + #set $num_header_words += 1 + header_buff[$num_header_words] = htonl(metadata.time_spec.ticks); + #set $num_header_words += 1 + #set $flags |= (0x1 << 20); + #end if + ########## Trailer ########## + #if $pred & $tlr_p + #set $flags |= (0x1 << 26); + #set $num_trailer_words = 1; + #else + #set $num_trailer_words = 0; + #end if + ########## Variables ########## + num_header_words32 = $num_header_words; + num_packet_words32 = $($num_header_words + $num_trailer_words) + num_payload_words32; + vrt_hdr_flags = $hex($flags); + break; + #end for + } + + //set the burst flags + if (metadata.start_of_burst) vrt_hdr_flags |= $hex(0x1 << 25); + if (metadata.end_of_burst) vrt_hdr_flags |= $hex(0x1 << 24); + + //fill in complete header word + header_buff[0] = htonl(vrt_hdr_flags | + ((packet_count & 0xf) << 16) | + (num_packet_words32 & 0xffff) + ); +} + +void vrt::unpack( + rx_metadata_t &metadata, //output + const boost::uint32_t *header_buff, //input + size_t &num_header_words32, //output + size_t &num_payload_words32, //output + size_t num_packet_words32, //input + size_t &packet_count //output +){ + //clear the metadata + metadata = rx_metadata_t(); + + //extract vrt header + boost::uint32_t vrt_hdr_word = ntohl(header_buff[0]); + size_t packet_words32 = vrt_hdr_word & 0xffff; + packet_count = (vrt_hdr_word >> 16) & 0xf; + + //failure cases + if (packet_words32 == 0 or num_packet_words32 < packet_words32) + throw std::runtime_error("bad vrt header or packet fragment"); + if (vrt_hdr_word & (0x7 << 29)) + throw std::runtime_error("unsupported vrt packet type"); + + boost::uint8_t pred = 0; + if(vrt_hdr_word & $hex(0x1 << 28)) pred |= $hex($sid_p); + if(vrt_hdr_word & $hex(0x1 << 27)) pred |= $hex($cid_p); + if(vrt_hdr_word & $hex(0x3 << 22)) pred |= $hex($tsi_p); + if(vrt_hdr_word & $hex(0x3 << 20)) pred |= $hex($tsf_p); + if(vrt_hdr_word & $hex(0x1 << 26)) pred |= $hex($tlr_p); + + switch(pred){ + #for $pred in range(2**5) + case $pred: + #set $set_has_time_spec = False + #set $num_header_words = 1 + ########## Stream ID ########## + #if $pred & $sid_p + metadata.has_stream_id = true; + metadata.stream_id = ntohl(header_buff[$num_header_words]); + #set $num_header_words += 1 + #end if + ########## Class ID ########## + #if $pred & $cid_p + #set $num_header_words += 1 + #set $num_header_words += 1 + #end if + ########## Integer Time ########## + #if $pred & $tsi_p + metadata.has_time_spec = true; + #set $set_has_time_spec = True + metadata.time_spec.secs = ntohl(header_buff[$num_header_words]); + #set $num_header_words += 1 + #end if + ########## Fractional Time ########## + #if $pred & $tsf_p + #if not $set_has_time_spec + metadata.has_time_spec = true; + #set $set_has_time_spec = True + #end if + #set $num_header_words += 1 + metadata.time_spec.ticks = ntohl(header_buff[$num_header_words]); + #set $num_header_words += 1 + #end if + ########## Trailer ########## + #if $pred & $tlr_p + #set $num_trailer_words = 1; + #else + #set $num_trailer_words = 0; + #end if + ########## Variables ########## + num_header_words32 = $num_header_words; + num_payload_words32 = packet_words32 - $($num_header_words + $num_trailer_words); + break; + #end for + } +} +""" + +from Cheetah import Template +def parse_str(_tmpl_text, **kwargs): return str(Template.Template(_tmpl_text, kwargs)) + +if __name__ == '__main__': + from Cheetah import Template + print parse_str(TMPL_TEXT, file=__file__) |