source: trunk/libs/newlib/src/libgloss/spu/crt0.S @ 468

Last change on this file since 468 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 4.8 KB
Line 
1/* (C) Copyright IBM Corp. 2005, 2006
2All rights reserved.
3
4Redistribution and use in source and binary forms, with or without
5modification, are permitted provided that the following conditions are met:
6
7    * Redistributions of source code must retain the above copyright notice,
8this list of conditions and the following disclaimer.
9    * Redistributions in binary form must reproduce the above copyright
10notice, this list of conditions and the following disclaimer in the
11documentation and/or other materials provided with the distribution.
12    * Neither the name of IBM nor the names of its contributors may be
13used to endorse or promote products derived from this software without
14specific prior written permission.
15
16THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26POSSIBILITY OF SUCH DAMAGE.
27*/
28
29/* crt0.S - entry function for C Runtime.
30 *
31 * With _STD_MAIN switch, the crt0.S will be compiled to crt2.o.
32 * The crt2.o sets up a C99-style interface for the SPU application's
33 * main() function, including a local copy of argv strings.
34 *
35 * The number of argument strings is passed in R3.  The size and EA
36 * location of the argument vector region is passed in R4.  Once the
37 * argv region is copied to the highest range of LS, and $SP is set
38 * just below it.
39 *
40 * Without _STD_MAIN, the crt0.S is compiled to crt1.o.
41 * The crt1.o prepares the entry for an SPU module. The main() function
42 * is called with different parameter list: spu_id, param and env
43 * are passed by R3, R4 and R5 respectively.
44 */
45
46#ifdef _STD_MAIN
47#define MFC_TAG_UPDATE_ALL      2
48#define MFC_GET_CMD             0x40
49#define TAGID                   0
50#define TAGMASK                 1
51#endif
52
53.comm __ea_local_store,16,16
54
55.text
56.global _start
57.type _start, @function
58       
59_start:
60        /* Save the local store base from $6.  */
61        stqr $6, __ea_local_store
62
63#ifdef _STD_MAIN
64        /*
65         * Copy the argument vector region from EA to LS.  The DMA
66         * parameters are passed in R4:
67         *
68         *        +-------+-------+-------+-------+
69         *     R4 |   LS  | EA-HI | EA-LO | SIZE  |
70         *        +-------+-------+-------+-------+
71         *  word     0       1       2       3
72         *
73         * By the end of this sequence, the prefered slot (word 0) of
74         * R4 will contain the LS offset of argv region, which also
75         * serves as the base offset for $SP.
76         */
77        wrch    $MFC_LSA, $4
78        rotqbyi $4, $4, 4
79        wrch    $MFC_EAH, $4
80        rotqbyi $4, $4, 4
81        wrch    $MFC_EAL, $4
82        rotqbyi $4, $4, 4
83        wrch    $MFC_Size, $4
84        rotqbyi $4, $4, 4
85        il      $LR, TAGID
86        wrch    $MFC_TagID, $LR
87
88        /* Issue MFC_GET_CMD, then wait for transfer of argument
89         * vector region to complete.
90         */
91        il      $LR, MFC_GET_CMD
92        wrch    $MFC_Cmd, $LR
93        il      $LR, TAGMASK
94        wrch    $MFC_WrTagMask, $LR
95        il      $LR, MFC_TAG_UPDATE_ALL
96        wrch    $MFC_WrTagUpdate, $LR
97        rdch    $LR, $MFC_RdTagStat
98#endif
99
100        /* Save parameter list of main function to the non-volatile
101         * registers. spu_thread module has three parameters, while
102         * spulet only has two.
103         */
104        ori     $80, $3, 0
105        ori     $81, $4, 0
106#ifndef _STD_MAIN
107        ori     $82, $5, 0
108#endif
109
110        /* The Link Register is initialized to NULL.
111         */
112        il      $LR, 0
113
114#ifdef _STD_MAIN       
115        /* For spulet, initialize stack pointer just below the argv region.
116         */
117        ai      $SP,$4,-16
118#else
119        /* For spe_thread module, the stack pointer is initialized
120         * below the area where __stack points to.
121         */
122        ila     $SP,__stack
123#endif
124        /* Initialize back chain to NULL.
125         */
126        stqd    $LR,0($SP)
127
128        /* Allocate 2 slots for stack frame.
129         */
130        stqd    $SP,-32($SP)
131        ai      $SP,$SP,-32
132
133        /* Save the Link Register in Link Register Save Area.
134         */
135        stqd    $LR,16($SP)
136
137        /* Calculate stack size.
138         */
139        ila     $3,_end
140        sf      $3,$3,$SP
141        rotqbyi $3,$3,12
142
143        /* The BE Linux ABI passes the stack size in $2, or use
144         * the default if $2 == 0.
145         */
146        rotqbyi $4,$2,12
147        ceqi    $5,$4,0
148        selb    $3,$4,$3,$5
149        fsmbi   $4,3840
150        selb    $SP,$SP,$3,$4
151
152        /* Call the _init function.
153         */
154        brsl    $LR, _init
155       
156        /* Call the _fini function at exit time.
157         */
158        ila     $3, _fini
159        brsl    $LR, atexit
160
161#ifdef _PROFILE
162        /* Call monstartup if profiling is enabled
163         */
164#ifdef _STD_MAIN
165        ila     $3,0
166#else
167        ori     $3,$80,0
168#endif
169        brsl    $LR, __monstartup
170#endif
171        ori     $3,$80,0
172        ori     $4,$81,0       
173#ifndef _STD_MAIN
174        ori     $5,$82,0
175#endif
176
177        /* Call the programs main.
178         */
179        brsl    $LR, main
180       
181        /* Call exit.
182         */
183        brsl    $LR, exit
184
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