beremiz

use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

2019-01-06, Andrey Skvortsov
68f4f2d4516b
use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

This code could be possible reused on low-end targets with limited RAM.

code to generate lookup table:
[---------------------------------------------------------------------]

/* CRC lookup table and initial state. */
uint32_t crc32_table[256];

/* Generate CRC32 lookup table. */
void GenerateCRC32Table(void)
{
unsigned int i, j;
/* Use CRC-32-IEEE 802.3 polynomial 0x04C11DB7 (bit reflected). */
uint32_t poly = 0xEDB88320;

for (i = 0; i <= 0xFF; i++)
{
uint32_t c = i;
for (j = 0 ; j < 8 ; j++)
c = (c & 1) ? (c >> 1 ) ^ poly : (c >> 1);
crc32_table[i] = c;
}
}

void main(void)
{
GenerateCRC32Table();
int j=0;
for(int i=0; i<256; i++) {
printf("0x%08X, ", crc32_table[i]);
if (++j >= 8) {
j = 0;
printf("\n");
}
}
}
[---------------------------------------------------------------------]
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This file is part of Beremiz, a Integrated Development Environment for
# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.
#
# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD
# Copyright (C) 2017: Andrey Skvortsov
#
# See COPYING file for copyrights details.
#
# 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 Street, Fifth Floor, Boston, MA 02110-1301, USA.
# Package initialisation
"""
Beremiz Targets
- Target are python packages, containing at least one "XSD" file
- Target class may inherit from a toolchain_(toolchainname)
- The target folder's name must match to name define in the XSD for TargetType
"""
from __future__ import absolute_import
from os import listdir, path
import util.paths as paths
_base_path = paths.AbsDir(__file__)
def _GetLocalTargetClassFactory(name):
return lambda: getattr(__import__(name, globals(), locals()), name+"_target")
targets = dict([(name, {"xsd": path.join(_base_path, name, "XSD"),
"class": _GetLocalTargetClassFactory(name),
"code": {fname: path.join(_base_path, name, fname)
for fname in listdir(path.join(_base_path, name))
if (fname.startswith("plc_%s_main" % name) and
fname.endswith(".c"))}})
for name in listdir(_base_path)
if (path.isdir(path.join(_base_path, name)) and
not name.startswith("__"))])
toolchains = {"gcc": path.join(_base_path, "XSD_toolchain_gcc"),
"makefile": path.join(_base_path, "XSD_toolchain_makefile")}
def GetBuilder(targetname):
return targets[targetname]["class"]()
def GetTargetChoices():
DictXSD_toolchain = {}
targetchoices = ""
# Get all xsd toolchains
for toolchainname, xsdfilename in toolchains.iteritems():
if path.isfile(xsdfilename):
DictXSD_toolchain["toolchain_"+toolchainname] = open(xsdfilename).read()
# Get all xsd targets
for _targetname, nfo in targets.iteritems():
xsd_string = open(nfo["xsd"]).read()
targetchoices += xsd_string % DictXSD_toolchain
return targetchoices
def GetTargetCode(targetname):
codedesc = targets[targetname]["code"]
code = "\n".join([open(fpath).read() for _fname, fpath in sorted(codedesc.items())])
return code
def GetHeader():
filename = paths.AbsNeighbourFile(__file__, "beremiz.h")
return open(filename).read()
def GetCode(name):
filename = paths.AbsNeighbourFile(__file__, name)
return open(filename).read()