PowerPC unfilter, decompress, and register definitions

Added Files:
	ppc_bxx.S ppc_d_nrv2e.S ppc_regs.h

committer: jreiser <jreiser> 1108855959 +0000

src/stub/ppc_bxx.S

@@ -0,0 +1,60 @@
+/* ppc_bxx.S -- PowerPC Branch Trick unfilter
+
+   This file is part of the UPX executable compressor.
+
+   Copyright (C) 2005 John F. Reiser
+   All Rights Reserved.
+
+   UPX and the UCL library are free software; you can redistribute them
+   and/or modify them 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; see the file COPYING.
+   If not, write to the Free Software Foundation, Inc.,
+   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+   John F. Reiser
+   <jreiser@users.sourceforge.net>
+*/
+
+#include "ppc_regs.h"
+
+ppcbxx:  # (*f_unf)(xo->buf, out_len, h.b_cto8, h.b_ftid);
+#define W_CTO 4  /* must match filteri/ppcbxx.h */
+
+#define ptr  a0
+#define len  a1
+#define cto8 a2
+#define ftid a3
+
+#define ptr0 a4
+
+	cmpli cr0,ftid,0xd0;       bnelr- cr0  # if (0xd0!=ftid) return;
+	rlwinm. len,len,32-2,2,31; beqlr- cr0   # if (0==(len>>=2)) return;
+	addi cto8,cto8,18<<W_CTO  # cat(bxx_opcode, cto8)
+	movr ptr0,ptr  # save base address
+	addi ptr,ptr,-4  # prepare for 'lwzu'
+	mtctr len  # count of words
+	b L20
+L10:
+	subf   t1,ptr,t0  # raw distance
+	add    t1,t1,ptr0  # relative to virtual address of base
+	rlwinm t1,t1,6+W_CTO,0,31-(6+W_CTO)  # shift displacement up to sign bit
+	srawi  t1,t1,6+W_CTO  # sign extended displacement
+	rlwimi t0,t1,0,6,31-2  # t0= unfiltered instruction
+	stw    t0,0(ptr)  # replace in memory
+	bdzlr-  # if (0==--ctr) return;  // extremely unlikely
+L20:
+	lwzu t0,4(ptr)  # t0= *++ptr;
+	rlwinm t1,t0,6+W_CTO,32-(6+W_CTO),31  # t1= top (6+W_CTO) bits of t0
+	cmpl cr0,t1,cto8; beq- cr0,L10  # unconditional branch marked with cto8; unlikely
+	bdnz+ L20  # if (0!=--ctr) goto L20;  // likely
+	ret
+