[apple/xnu.git] / bsd / dev / i386 / munge.s

/*
 * Coyright (c) 2005-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

/*
 * Syscall argument mungers.
 *
 * The data to be munged has been explicitly copied in to the argument area,
 * and will be munged in place in the uu_arg[] array.  Because of this, the
 * functions all take the same arguments as their PPC equivalents, but the
 * first argument is ignored.  These mungers are for 32-bit app's syscalls,
 * since 64-bit args are stored into the save area (which overlays the
 * uu_args) in the order the syscall ABI calls for.
 *
 * The issue is that the incoming args are 32-bit, but we must expand
 * them in place into 64-bit args, as if they were from a 64-bit process.
 *
 * There are several functions in this file.  Each takes two parameters:
 *
 *	void	munge_XXXX( const void *regs, void *uu_args);
 *
 * The name of the function encodes the number and type of the parameters,
 * as follows:
 *
 *	w = a 32-bit value such as an int or a 32-bit ptr, that does not
 *	    require sign extension.  These are handled by zeroing a word
 *          of output, and copying a word from input to output.
 *
 *	s = a 32-bit value such as a long, which must be sign-extended to
 *	    a 64-bit long-long in the uu_args.  These are handled by
 *	    loading a word of input and sign extending it to a double,
 *          and storing two words of output.
 *
 *	l = a 64-bit long-long.  These are handled by copying two words
 *          of input to the output.
 *
 * For example, "munge_wls" takes a word, a long-long, and a word.  This
 * takes four words in the uu_arg[] area: the first word is in one, the
 * long-long takes two, and the final word is in the fourth.  We store six
 * words: the low word is left in place, followed by a 0, followed by the
 * two words of the long-long, followed by the low word and the sign extended
 * high word of the preceeding low word.
 *
 * Because this is an in-place modification, we actually start at the end
 * of uu_arg[] and work our way back to the beginning of the array.
 *
 * As you can see, we save a lot of code by collapsing mungers that are
 * prefixes or suffixes of each other.
 */
#include <i386/asm.h>

ENTRY(munge_w)
	movl	8(%esp),%ecx	// get &uu_args
	movl	$0,4(%ecx)
	ret
	
ENTRY(munge_ww)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	jmp	Lw2
ENTRY(munge_www)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	jmp	Lw3
ENTRY(munge_wwww)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	jmp	Lw4
ENTRY(munge_wwwww)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	jmp	Lw5
ENTRY(munge_wwwwww)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	jmp	Lw6
ENTRY(munge_wwwwwww)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	jmp	Lw7
ENTRY(munge_wwwwwwww)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	movl	28(%ecx),%eax
	movl	%eax,56(%ecx)
	movl	%edx,60(%ecx)
Lw7:
	movl	24(%ecx),%eax
	movl	%eax,48(%ecx)
	movl	%edx,52(%ecx)
Lw6:
	movl	20(%ecx),%eax
	movl	%eax,40(%ecx)
	movl	%edx,44(%ecx)
Lw5:
	movl	16(%ecx),%eax
	movl	%eax,32(%ecx)
	movl	%edx,36(%ecx)
Lw4:
	movl	12(%ecx),%eax
	movl	%eax,24(%ecx)
	movl	%edx,28(%ecx)
Lw3:
	movl	8(%ecx),%eax
	movl	%eax,16(%ecx)
	movl	%edx,20(%ecx)
Lw2:
	movl	4(%ecx),%eax
	movl	%eax,8(%ecx)
	movl	%edx,12(%ecx)
	movl	%edx,4(%ecx)
	ret


Entry(munge_wl)			/* Costs an extra w move to do this */
ENTRY(munge_wlw)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	movl	12(%ecx),%eax
	movl	%eax,16(%ecx)
	movl	%edx,20(%ecx)
	movl	8(%ecx),%eax
	movl	%eax,12(%ecx)
	movl	4(%ecx),%eax
	movl	%eax,8(%ecx)
	movl	%edx,4(%ecx)
	ret

Entry(munge_wwwlw)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	movl	20(%ecx),%eax
	movl	%eax,32(%ecx)
	movl	%edx,36(%ecx)
	jmp	Lwwwl
	
ENTRY(munge_wwwl)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
Lwwwl:
	movl	12(%ecx),%eax
	movl	%eax,24(%ecx)
	movl	16(%ecx),%eax
	movl	%eax,28(%ecx)
	jmp	Lw3

ENTRY(munge_wwwwlw)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	movl	24(%ecx),%eax
	movl	%eax,40(%ecx)
	movl	%edx,44(%ecx)
	jmp	Lwwwwl

ENTRY(munge_wwwwl)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
Lwwwwl:
	movl	16(%ecx),%eax
	movl	%eax,32(%ecx)
	movl	20(%ecx),%eax
	movl	%eax,36(%ecx)
	jmp	Lw4

ENTRY(munge_wwwwwl)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	movl	20(%ecx),%eax
	movl	%eax,40(%ecx)
	movl	24(%ecx),%eax
	movl	%eax,44(%ecx)
	jmp	Lw5

ENTRY(munge_wwwwwwlw)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	movl	32(%ecx),%eax
	movl	%eax,56(%ecx)
	movl	%edx,60(%ecx)
	movl	24(%ecx),%eax
	movl	%eax,48(%ecx)
	movl	28(%ecx),%eax
	movl	%eax,52(%ecx)
	jmp 	Lw6
	

ENTRY(munge_wwwwwwll)
	movl	8(%esp),%ecx	// get &uu_args
	xorl	%edx,%edx
	movl	32(%ecx),%eax
	movl	%eax,56(%ecx)
	movl	36(%ecx),%eax
	movl	%eax,60(%ecx)
	movl	24(%ecx),%eax
	movl	%eax,48(%ecx)
	movl	28(%ecx),%eax
	movl	%eax,52(%ecx)
	jmp 	Lw6

ENTRY(munge_wsw)
	movl	8(%esp),%ecx	// get &uu_args
	movl	8(%ecx),%eax
	movl	%eax,16(%ecx)
	movl	$0,20(%ecx)
	movl	4(%ecx),%eax
	cltd
	movl	%eax,8(%ecx)
	movl	%edx,12(%ecx)
	movl	$0,4(%ecx)
	ret

ENTRY(munge_wws)
	movl	8(%esp),%ecx	// get &uu_args
	movl	8(%ecx),%eax
	cltd
	movl	%eax,16(%ecx)
	movl	%edx,20(%ecx)
	xorl	%edx,%edx
	jmp	Lw2

ENTRY(munge_wwwsw)
	movl	8(%esp),%ecx	// get &uu_args
	movl	16(%ecx),%eax
	movl	%eax,32(%ecx)
	movl	$0,36(%ecx)
	movl	12(%ecx),%eax
	cltd
	movl	%eax,24(%ecx)
	movl	%edx,28(%ecx)
	xorl	%edx,%edx
	jmp	Lw3

ENTRY(munge_llllll)
	ret						// actually, this method has nothing to do - all
							// arguments are already 64-bits, with no mixing of
							// args that need sign/zero extension
Commit	Line	Data
0c530ab8 A	1	/*
	2	* Coyright (c) 2005-2006 Apple Computer, Inc. All rights reserved.
	3	*
2d21ac55 A	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
0c530ab8 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
0c530ab8 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
0c530ab8 A	27	*/
	28
	29	/*
	30	* Syscall argument mungers.
	31	*
2d21ac55	32	* The data to be munged has been explicitly copied in to the argument area,
0c530ab8 A	33	* and will be munged in place in the uu_arg[] array. Because of this, the
	34	* functions all take the same arguments as their PPC equivalents, but the
	35	* first argument is ignored. These mungers are for 32-bit app's syscalls,
	36	* since 64-bit args are stored into the save area (which overlays the
	37	* uu_args) in the order the syscall ABI calls for.
	38	*
	39	* The issue is that the incoming args are 32-bit, but we must expand
	40	* them in place into 64-bit args, as if they were from a 64-bit process.
	41	*
	42	* There are several functions in this file. Each takes two parameters:
	43	*
	44	* void munge_XXXX( const void regs, void uu_args);
	45	*
	46	* The name of the function encodes the number and type of the parameters,
	47	* as follows:
	48	*
	49	* w = a 32-bit value such as an int or a 32-bit ptr, that does not
	50	* require sign extension. These are handled by zeroing a word
	51	* of output, and copying a word from input to output.
	52	*
	53	* s = a 32-bit value such as a long, which must be sign-extended to
	54	* a 64-bit long-long in the uu_args. These are handled by
	55	* loading a word of input and sign extending it to a double,
	56	* and storing two words of output.
	57	*
	58	* l = a 64-bit long-long. These are handled by copying two words
	59	* of input to the output.
	60	*
	61	* For example, "munge_wls" takes a word, a long-long, and a word. This
	62	* takes four words in the uu_arg[] area: the first word is in one, the
	63	* long-long takes two, and the final word is in the fourth. We store six
	64	* words: the low word is left in place, followed by a 0, followed by the
	65	* two words of the long-long, followed by the low word and the sign extended
	66	* high word of the preceeding low word.
	67	*
	68	* Because this is an in-place modification, we actually start at the end
	69	* of uu_arg[] and work our way back to the beginning of the array.
	70	*
	71	* As you can see, we save a lot of code by collapsing mungers that are
	72	* prefixes or suffixes of each other.
	73	*/
	74	#include <i386/asm.h>
	75
	76	ENTRY(munge_w)
	77	movl 8(%esp),%ecx // get &uu_args
	78	movl $0,4(%ecx)
	79	ret
	80
	81	ENTRY(munge_ww)
	82	movl 8(%esp),%ecx // get &uu_args
	83	xorl %edx,%edx
	84	jmp Lw2
	85	ENTRY(munge_www)
	86	movl 8(%esp),%ecx // get &uu_args
	87	xorl %edx,%edx
	88	jmp Lw3
	89	ENTRY(munge_wwww)
	90	movl 8(%esp),%ecx // get &uu_args
	91	xorl %edx,%edx
	92	jmp Lw4
	93	ENTRY(munge_wwwww)
	94	movl 8(%esp),%ecx // get &uu_args
	95	xorl %edx,%edx
	96	jmp Lw5
97	ENTRY(munge_wwwwww)
98	movl 8(%esp),%ecx // get &uu_args
99	xorl %edx,%edx
100	jmp Lw6
101	ENTRY(munge_wwwwwww)
102	movl 8(%esp),%ecx // get &uu_args
103	xorl %edx,%edx
104	jmp Lw7
105	ENTRY(munge_wwwwwwww)
106	movl 8(%esp),%ecx // get &uu_args
107	xorl %edx,%edx
108	movl 28(%ecx),%eax
109	movl %eax,56(%ecx)
110	movl %edx,60(%ecx)
111	Lw7:
112	movl 24(%ecx),%eax
113	movl %eax,48(%ecx)
114	movl %edx,52(%ecx)
115	Lw6:
116	movl 20(%ecx),%eax
117	movl %eax,40(%ecx)
118	movl %edx,44(%ecx)
119	Lw5:
120	movl 16(%ecx),%eax
121	movl %eax,32(%ecx)
122	movl %edx,36(%ecx)
123	Lw4:
124	movl 12(%ecx),%eax
125	movl %eax,24(%ecx)
126	movl %edx,28(%ecx)
127	Lw3:
128	movl 8(%ecx),%eax
129	movl %eax,16(%ecx)
130	movl %edx,20(%ecx)
131	Lw2:
132	movl 4(%ecx),%eax
133	movl %eax,8(%ecx)
134	movl %edx,12(%ecx)
135	movl %edx,4(%ecx)
136	ret
137
138
139	Entry(munge_wl) /* Costs an extra w move to do this */
140	ENTRY(munge_wlw)
141	movl 8(%esp),%ecx // get &uu_args
142	xorl %edx,%edx
143	movl 12(%ecx),%eax
144	movl %eax,16(%ecx)
145	movl %edx,20(%ecx)
146	movl 8(%ecx),%eax
147	movl %eax,12(%ecx)
148	movl 4(%ecx),%eax
149	movl %eax,8(%ecx)
150	movl %edx,4(%ecx)
151	ret
152
b0d623f7 A	153	Entry(munge_wwwlw)
	154	movl 8(%esp),%ecx // get &uu_args
	155	xorl %edx,%edx
	156	movl 20(%ecx),%eax
	157	movl %eax,32(%ecx)
	158	movl %edx,36(%ecx)
	159	jmp Lwwwl
	160
0c530ab8 A	161	ENTRY(munge_wwwl)
	162	movl 8(%esp),%ecx // get &uu_args
	163	xorl %edx,%edx
b0d623f7	164	Lwwwl:
0c530ab8 A	165	movl 12(%ecx),%eax
	166	movl %eax,24(%ecx)
	167	movl 16(%ecx),%eax
	168	movl %eax,28(%ecx)
	169	jmp Lw3
	170
b0d623f7 A	171	ENTRY(munge_wwwwlw)
	172	movl 8(%esp),%ecx // get &uu_args
	173	xorl %edx,%edx
	174	movl 24(%ecx),%eax
	175	movl %eax,40(%ecx)
	176	movl %edx,44(%ecx)
	177	jmp Lwwwwl
	178
0c530ab8 A	179	ENTRY(munge_wwwwl)
	180	movl 8(%esp),%ecx // get &uu_args
	181	xorl %edx,%edx
b0d623f7	182	Lwwwwl:
0c530ab8 A	183	movl 16(%ecx),%eax
	184	movl %eax,32(%ecx)
	185	movl 20(%ecx),%eax
	186	movl %eax,36(%ecx)
	187	jmp Lw4
	188
	189	ENTRY(munge_wwwwwl)
	190	movl 8(%esp),%ecx // get &uu_args
	191	xorl %edx,%edx
	192	movl 20(%ecx),%eax
	193	movl %eax,40(%ecx)
	194	movl 24(%ecx),%eax
	195	movl %eax,44(%ecx)
	196	jmp Lw5
	197
b0d623f7 A	198	ENTRY(munge_wwwwwwlw)
	199	movl 8(%esp),%ecx // get &uu_args
	200	xorl %edx,%edx
	201	movl 32(%ecx),%eax
	202	movl %eax,56(%ecx)
	203	movl %edx,60(%ecx)
	204	movl 24(%ecx),%eax
	205	movl %eax,48(%ecx)
	206	movl 28(%ecx),%eax
	207	movl %eax,52(%ecx)
	208	jmp Lw6
	209
	210
	211	ENTRY(munge_wwwwwwll)
	212	movl 8(%esp),%ecx // get &uu_args
	213	xorl %edx,%edx
	214	movl 32(%ecx),%eax
	215	movl %eax,56(%ecx)
	216	movl 36(%ecx),%eax
	217	movl %eax,60(%ecx)
	218	movl 24(%ecx),%eax
	219	movl %eax,48(%ecx)
	220	movl 28(%ecx),%eax
	221	movl %eax,52(%ecx)
	222	jmp Lw6
	223
0c530ab8 A	224	ENTRY(munge_wsw)
	225	movl 8(%esp),%ecx // get &uu_args
	226	movl 8(%ecx),%eax
	227	movl %eax,16(%ecx)
	228	movl $0,20(%ecx)
	229	movl 4(%ecx),%eax
	230	cltd
	231	movl %eax,8(%ecx)
	232	movl %edx,12(%ecx)
	233	movl $0,4(%ecx)
	234	ret
	235
	236	ENTRY(munge_wws)
	237	movl 8(%esp),%ecx // get &uu_args
	238	movl 8(%ecx),%eax
	239	cltd
	240	movl %eax,16(%ecx)
	241	movl %edx,20(%ecx)
	242	xorl %edx,%edx
	243	jmp Lw2
	244
	245	ENTRY(munge_wwwsw)
	246	movl 8(%esp),%ecx // get &uu_args
	247	movl 16(%ecx),%eax
	248	movl %eax,32(%ecx)
	249	movl $0,36(%ecx)
	250	movl 12(%ecx),%eax
	251	cltd
	252	movl %eax,24(%ecx)
	253	movl %edx,28(%ecx)
	254	xorl %edx,%edx
	255	jmp Lw3
b0d623f7 A	256
	257	ENTRY(munge_llllll)
	258	ret // actually, this method has nothing to do - all
	259	// arguments are already 64-bits, with no mixing of
	260	// args that need sign/zero extension