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1 /*
2 * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
3 * The President and Fellows of Harvard College.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 /*
31 * Assembler-level thread startup trampoline.
32 */
33
34 #include <kern/mips/regdefs.h>
35
36 .text
37 .set noreorder
38
39 .globl mips_threadstart
40 .type mips_threadstart,@function
41 .ent mips_threadstart
42 mips_threadstart:
43
44 /*
45 * This code doesn't take normal arguments. It's reached when
46 * switchframe_switch switches to a new thread. switchframe_switch
47 * does "j ra"; ra gets preloaded in switchframe_init to come here.
48 *
49 * Our arguments are in callee-save registers, as follows:
50 *
51 * s0 entrypoint
52 * s1 data1
53 * s2 data2
54 *
55 * We need to rearrange these so as to call the normal C function
56 * thread_startup(void (*entrypoint)(), void *data1, unsigned long data2).
57 */
58
59 addiu sp, sp, -16 /* make our stack frame */
60
61 move ra, $0 /* clear return addr so we're top of the call stack */
62
63 move a0, s0 /* load arguments and call */
64 move a1, s1
65 j thread_startup
66 move a2, s2 /* (in delay slot) */
67
68 .end mips_threadstart