[openfirmware] r1501 - cpu/x86
svn at openfirmware.info
svn at openfirmware.info
Wed Nov 25 21:27:13 CET 2009
Author: wmb
Date: 2009-11-25 21:27:12 +0100 (Wed, 25 Nov 2009)
New Revision: 1501
Added:
cpu/x86/adler32.fth
Log:
Added Adler32 checksum routine to source tree; unused at present.
Added: cpu/x86/adler32.fth
===================================================================
--- cpu/x86/adler32.fth (rev 0)
+++ cpu/x86/adler32.fth 2009-11-25 20:27:12 UTC (rev 1501)
@@ -0,0 +1,57 @@
+\ See license at end of file
+purpose: Adler-32 checksum (used in zlib compression)
+
+code adler32 ( adr len -- adler )
+ 0 [sp] bp xchg \ bp: len and save bp
+ 4 [sp] si xchg \ si: adr and save si
+ bp cx mov \ cx: len
+ di push \ Save di
+ d# 65521 # di mov \ MOD_ADLER
+
+ bx bx xor \ A
+ bx inc \ bx: A=1
+ bp bp xor \ bp: B=0
+ begin
+ ax ax xor
+ al lods \ ax: data[index]
+ bx ax add \ ax: A + data[index]
+ dx dx xor \ Clear high word of dividend
+ di div \ Remainder in dx
+ dx bx mov \ bx: A = (A + data[index]) % MOD_ADLER
+ bx bp add \ bp: B + A
+ dx dx xor \ Clear high word of dividend
+ bp ax mov \ ax: low word of dividend
+ di div \ Remainder in dx
+ dx bp mov \ bp: B = (B + A) % MOD_ADLER
+ loopa
+ d# 16 # bp shl \ bp: (B << 16)
+ bp bx or \ bx: (B << 16) | A
+ di pop \ Restore di
+ bp pop \ Restore bp
+ si pop \ Restore si
+ bx push \ Return result
+c;
+
+\ LICENSE_BEGIN
+\ Copyright (c) 2006 FirmWorks
+\
+\ Permission is hereby granted, free of charge, to any person obtaining
+\ a copy of this software and associated documentation files (the
+\ "Software"), to deal in the Software without restriction, including
+\ without limitation the rights to use, copy, modify, merge, publish,
+\ distribute, sublicense, and/or sell copies of the Software, and to
+\ permit persons to whom the Software is furnished to do so, subject to
+\ the following conditions:
+\
+\ The above copyright notice and this permission notice shall be
+\ included in all copies or substantial portions of the Software.
+\
+\ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+\ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+\ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+\ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+\ LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+\ OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+\ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+\
+\ LICENSE_END
More information about the openfirmware
mailing list