Edit
openbios/openboot/obp/pkg/decompressor/sparc
Stefan Reinauer
- decomp.fth
-
\ ========== Copyright Header Begin ========================================== \ \ Hypervisor Software File: decomp.fth \ \ Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. \ \ - Do no alter or remove copyright notices \ \ - Redistribution and use of this software in source and binary forms, with \ or without modification, are permitted provided that the following \ conditions are met: \ \ - Redistribution of source code must retain the above copyright notice, \ this list of conditions and the following disclaimer. \ \ - Redistribution in binary form must reproduce the above copyright notice, \ this list of conditions and the following disclaimer in the \ documentation and/or other materials provided with the distribution. \ \ Neither the name of Sun Microsystems, Inc. or the names of contributors \ may be used to endorse or promote products derived from this software \ without specific prior written permission. \ \ This software is provided "AS IS," without a warranty of any kind. \ ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, \ INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A \ PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN \ MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR \ ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR \ DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN \ OR ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR \ FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE \ DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, \ ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF \ SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. \ \ You acknowledge that this software is not designed, licensed or \ intended for use in the design, construction, operation or maintenance of \ any nuclear facility. \ \ ========== Copyright Header End ============================================ id: @(#)decomp.fth 1.2 01/04/06 purpose: copyright: Copyright 1997-2001 Sun Microsystems, Inc. All Rights Reserved headerless \ In: \ scr = decomp data ptr \ sc1 = src addr \ sc2 = #bytes remaining \ Out: \ tos = byte|-1 \ label decomp-getabyte scr 0 >source-addr sc1 ld \ scr = src addr scr 0 >source-size sc2 ld \ sc1 = #bytes left sc2 1 sc2 subcc 0>= if %g0 -1 tos add \ (delay) sc1 %g0 tos ldub \ get data sc1 1 sc1 add sc1 scr 0 >source-addr st \ update src pointer then retl sc2 scr 0 >source-size st \ update #bytes left (delay) end-code \ \ Forth Version of assembler routine \ code decomp-getbyte ( data-buffer -- byte|-1 ) decomp-getabyte call tos scr move c; code decomp-putbyte ( byte buffer -- ) tos sc1 move sp scr pop sp tos pop sc1 0 >dest-addr sc2 ld \ get dest address scr sc2 %g0 stb \ write data sc2 1 sc2 add sc2 sc1 0 >dest-addr st \ update ptr c; \ In: \ tos \ Scratch: \ scr, sc1, sc2 - by getabyte \ sc3, sc4, sc5 - by getcode \ Out: \ tos \ code decomp-getcode ( bits buffer -- code ) tos scr move \ preserve buffer ptr sp sc3 pop scr 0 >getcode-offset sc4 ld \ get previous offset scr 0 >getcode-oldcode sc5 ld \ get previous code \ Watch the 'if' trick coming up. begin decomp-getabyte call nop tos -1 %g0 subcc <> if but tos sc4 sc1 sll \ (byte << r_off) (delay) sc4 8 sc4 add \ r_off += 8 sc4 sc3 cmp >= until sc5 sc1 sc5 add \ code += (byte << r_off) (delay) sc5 sc3 sc1 srl \ (code >> bits) sc4 sc3 sc2 sub \ r_off - bits sc1 scr 0 >getcode-oldcode st \ getcode_oldcode = (code >> bits) sc2 scr 0 >getcode-offset st \ getcode_offset = (r_off - bits) %g0 1 scr sub scr sc3 scr sllx \ mask = (-1 << bits) sc5 scr tos andn \ tos = tos & ~mask then c;