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");
}
}
}
[---------------------------------------------------------------------]
/*
Stylesheet used to list EtherCat dictionnary entries.
Copyright (C) 2011-2014: Laurent BESSARD
Distributed under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
See COPYING file for copyrights details.
*/
include yslt.yml2
estylesheet xmlns:ns="entries_list_ns"
extension-element-prefixes="ns"
exclude-result-prefixes="ns" {
param "min_index";
param "max_index";
template "text()";
template "Device" {
apply "Profile/Dictionary/Objects/Object";
foreach "RxPdo" {
call "pdo_entries" with "direction", "'Receive'";
}
foreach "TxPdo" {
call "pdo_entries" with "direction", "'Transmit'";
}
}
template "Object" {
variable "index" > «ns:HexDecValue(Index/text())»
variable "entry_name" > «ns:EntryName(Name)»
choose {
when "$index >= $min_index and $index <= $max_index" {
variable "datatype_name" > «Type/text()»
choose {
when "ancestor::Dictionary/child::DataTypes/DataType[Name/text()=$datatype_name][SubItem]" {
apply "ancestor::Dictionary/child::DataTypes/DataType[Name/text()=$datatype_name][SubItem]" {
with "index" > «$index»
with "entry_name" > «$entry_name»
}
}
otherwise {
variable "subindex" > 0
variable "entry" {
> «ns:AddEntry($index, $subindex, $entry_name, $datatype_name, BitSize/text(), Flags/Access/text(), Flags/PdoMapping/text())»
}
}
}
}
}
}
template "DataType" {
param "index";
param "entry_name";
foreach "SubItem" {
variable "subindex" > «ns:HexDecValue(SubIdx/text())»
variable "subentry_name" > «$entry_name» - «ns:EntryName(DisplayName, Name/text())»
variable "entry" {
> «ns:AddEntry($index, $subindex, $subentry_name, Type/text(), BitSize/text(), Flags/Access/text(), Flags/PdoMapping/text())»
}
}
}
function "pdo_entries" {
param "direction";
variable "pdo_index" > «ns:HexDecValue(Index/text())»
variable "pdo_name" > «ns:EntryName(Name)»
foreach "Entry" {
variable "index" > «ns:HexDecValue(Index/text())»
choose {
when "$index >= $min_index and $index <= $max_index" {
variable "subindex" > «ns:HexDecValue(SubIndex/text())»
variable "subentry_name" > «ns:EntryName(Name)»
variable "access" {
choose {
when "$direction='Transmit'" > ro
otherwise > wo
}
}
variable "pdo_mapping" {
choose {
when "$direction='Transmit'" > T
otherwise > R
}
}
variable "entry" {
> «ns:AddEntry($index, $subindex, $subentry_name, DataType/text(), BitLen/text(), $access, $pdo_mapping, $pdo_index, $pdo_name, $direction)»
}
}
}
}
}
}