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[nixio] implement dow_crc8 in C

This commit is contained in:
Bart Van Der Meerssche 2011-01-10 01:22:20 +01:00
parent d60e749873
commit 7c3ad70ff2
2 changed files with 53 additions and 25 deletions
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23
mote/v2/openwrt/package/flukso/luasrc/flukso/spi.lua
View File

@ -31,27 +31,6 @@ local getfenv, setmetatable, tonumber =
module (...)
local modenv = getfenv()
-- private
local function dow_crc(sequence, crc)
crc = crc or 0x00
local r1 = { 0x00, 0x5e, 0xbc, 0xe2, 0x61, 0x3f, 0xdd, 0x83,
0xc2, 0x9c, 0x7e, 0x20, 0xa3, 0xfd, 0x1f, 0x41 }
local r2 = { 0x00, 0x9d, 0x23, 0xbe, 0x46, 0xdb, 0x65, 0xf8,
0x8c, 0x11, 0xaf, 0x32, 0xca, 0x57, 0xe9, 0x74 }
local first_char = sequence:sub(1, 1)
if first_char ~= '' then
local i = nixio.bit.band(nixio.bit.bxor(first_char:byte(), crc), 0xff)
crc = nixio.bit.bxor(r1[nixio.bit.band(i, 0xf) + 1], r2[nixio.bit.rshift(i, 4) + 1])
return dow_crc(sequence:sub(2, -1), crc)
else
return nixio.bin.hexlify(string.char(crc))
end
end
--- Create a new spi message object.
--
-- Attributes:
@ -153,7 +132,7 @@ function rx(msg, cdev)
msg.received.crc = msg.received.l:sub(-2, -1)
msg.received.l = msg.received.l:sub(1, -3)
if dow_crc(msg.received.l) ~= msg.received.crc then
if nixio.bin.dow_crc(msg.received.l) ~= tonumber(BinDecHex.Hex2Dec(msg.received.crc)) then
--> TODO implement crc error counter
msg.received.l = ''
end

49
mote/v2/openwrt/package/luci/libs/nixio/src/binary.c
View File

@ -94,6 +94,41 @@ static const uint32_t nixio__crc32_tbl[] = {
0x2d02ef8dU
};
static const uint8_t nixio__dow_crc_tbl[] = {
0x00, 0x5e, 0xbc, 0xe2, 0x61, 0x3f, 0xdd, 0x83,
0xc2, 0x9c, 0x7e, 0x20, 0xa3, 0xfd, 0x1f, 0x41,
0x9d, 0xc3, 0x21, 0x7f, 0xfc, 0xa2, 0x40, 0x1e,
0x5f, 0x01, 0xe3, 0xbd, 0x3e, 0x60, 0x82, 0xdc,
0x23, 0x7d, 0x9f, 0xc1, 0x42, 0x1c, 0xfe, 0xa0,
0xe1, 0xbf, 0x5d, 0x03, 0x80, 0xde, 0x3c, 0x62,
0xbe, 0xe0, 0x02, 0x5c, 0xdf, 0x81, 0x63, 0x3d,
0x7c, 0x22, 0xc0, 0x9e, 0x1d, 0x43, 0xa1, 0xff,
0x46, 0x18, 0xfa, 0xa4, 0x27, 0x79, 0x9b, 0xc5,
0x84, 0xda, 0x38, 0x66, 0xe5, 0xbb, 0x59, 0x07,
0xdb, 0x85, 0x67, 0x39, 0xba, 0xe4, 0x06, 0x58,
0x19, 0x47, 0xa5, 0xfb, 0x78, 0x26, 0xc4, 0x9a,
0x65, 0x3b, 0xd9, 0x87, 0x04, 0x5a, 0xb8, 0xe6,
0xa7, 0xf9, 0x1b, 0x45, 0xc6, 0x98, 0x7a, 0x24,
0xf8, 0xa6, 0x44, 0x1a, 0x99, 0xc7, 0x25, 0x7b,
0x3a, 0x64, 0x86, 0xd8, 0x5b, 0x05, 0xe7, 0xb9,
0x8c, 0xd2, 0x30, 0x6e, 0xed, 0xb3, 0x51, 0x0f,
0x4e, 0x10, 0xf2, 0xac, 0x2f, 0x71, 0x93, 0xcd,
0x11, 0x4f, 0xad, 0xf3, 0x70, 0x2e, 0xcc, 0x92,
0xd3, 0x8d, 0x6f, 0x31, 0xb2, 0xec, 0x0e, 0x50,
0xaf, 0xf1, 0x13, 0x4d, 0xce, 0x90, 0x72, 0x2c,
0x6d, 0x33, 0xd1, 0x8f, 0x0c, 0x52, 0xb0, 0xee,
0x32, 0x6c, 0x8e, 0xd0, 0x53, 0x0d, 0xef, 0xb1,
0xf0, 0xae, 0x4c, 0x12, 0x91, 0xcf, 0x2d, 0x73,
0xca, 0x94, 0x76, 0x28, 0xab, 0xf5, 0x17, 0x49,
0x08, 0x56, 0xb4, 0xea, 0x69, 0x37, 0xd5, 0x8b,
0x57, 0x09, 0xeb, 0xb5, 0x36, 0x68, 0x8a, 0xd4,
0x95, 0xcb, 0x29, 0x77, 0xf4, 0xaa, 0x48, 0x16,
0xe9, 0xb7, 0x55, 0x0b, 0x88, 0xd6, 0x34, 0x6a,
0x2b, 0x75, 0x97, 0xc9, 0x4a, 0x14, 0xf6, 0xa8,
0x74, 0x2a, 0xc8, 0x96, 0x15, 0x4b, 0xa9, 0xf7,
0xb6, 0xe8, 0x0a, 0x54, 0xd7, 0x89, 0x6b, 0x35,
};
static int nixio_bin_crc32(lua_State *L) {
size_t len;
const char *buffer = luaL_checklstring(L, 1, &len);
@ -108,6 +143,19 @@ static int nixio_bin_crc32(lua_State *L) {
return 1;
}
static int nixio_bin_dow_crc(lua_State *L) {
size_t len;
const char *buffer = luaL_checklstring(L, 1, &len);
uint8_t value = (uint8_t)luaL_optinteger(L, 2, 0);
for (size_t i=0; i<len; i++) {
value = nixio__dow_crc_tbl[(value ^ buffer[i]) & 0xff];
}
lua_pushinteger(L, (int)value);
return 1;
}
static int nixio_bin_hexlify(lua_State *L) {
size_t len, lenout;
luaL_checktype(L, 1, LUA_TSTRING);
@ -300,6 +348,7 @@ static const luaL_reg R[] = {
{"hexlify", nixio_bin_hexlify},
{"unhexlify", nixio_bin_unhexlify},
{"crc32", nixio_bin_crc32},
{"dow_crc", nixio_bin_dow_crc},
{"b64encode", nixio_bin_b64encode},
{"b64decode", nixio_bin_b64decode},
{NULL, NULL}