1*0a6a1f1dSLionel Sambuc /* ===----- trampoline_setup.c - Implement __trampoline_setup -------------===
2*0a6a1f1dSLionel Sambuc *
3*0a6a1f1dSLionel Sambuc * The LLVM Compiler Infrastructure
4*0a6a1f1dSLionel Sambuc *
5*0a6a1f1dSLionel Sambuc * This file is dual licensed under the MIT and the University of Illinois Open
6*0a6a1f1dSLionel Sambuc * Source Licenses. See LICENSE.TXT for details.
7*0a6a1f1dSLionel Sambuc *
8*0a6a1f1dSLionel Sambuc * ===----------------------------------------------------------------------===
9*0a6a1f1dSLionel Sambuc */
10*0a6a1f1dSLionel Sambuc
11*0a6a1f1dSLionel Sambuc #include "int_lib.h"
12*0a6a1f1dSLionel Sambuc
13*0a6a1f1dSLionel Sambuc extern void __clear_cache(void* start, void* end);
14*0a6a1f1dSLionel Sambuc
15*0a6a1f1dSLionel Sambuc /*
16*0a6a1f1dSLionel Sambuc * The ppc compiler generates calls to __trampoline_setup() when creating
17*0a6a1f1dSLionel Sambuc * trampoline functions on the stack for use with nested functions.
18*0a6a1f1dSLionel Sambuc * This function creates a custom 40-byte trampoline function on the stack
19*0a6a1f1dSLionel Sambuc * which loads r11 with a pointer to the outer function's locals
20*0a6a1f1dSLionel Sambuc * and then jumps to the target nested function.
21*0a6a1f1dSLionel Sambuc */
22*0a6a1f1dSLionel Sambuc
23*0a6a1f1dSLionel Sambuc #if __ppc__ && !defined(__powerpc64__)
24*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI void
__trampoline_setup(uint32_t * trampOnStack,int trampSizeAllocated,const void * realFunc,void * localsPtr)25*0a6a1f1dSLionel Sambuc __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated,
26*0a6a1f1dSLionel Sambuc const void* realFunc, void* localsPtr)
27*0a6a1f1dSLionel Sambuc {
28*0a6a1f1dSLionel Sambuc /* should never happen, but if compiler did not allocate */
29*0a6a1f1dSLionel Sambuc /* enough space on stack for the trampoline, abort */
30*0a6a1f1dSLionel Sambuc if ( trampSizeAllocated < 40 )
31*0a6a1f1dSLionel Sambuc compilerrt_abort();
32*0a6a1f1dSLionel Sambuc
33*0a6a1f1dSLionel Sambuc /* create trampoline */
34*0a6a1f1dSLionel Sambuc trampOnStack[0] = 0x7c0802a6; /* mflr r0 */
35*0a6a1f1dSLionel Sambuc trampOnStack[1] = 0x4800000d; /* bl Lbase */
36*0a6a1f1dSLionel Sambuc trampOnStack[2] = (uint32_t)realFunc;
37*0a6a1f1dSLionel Sambuc trampOnStack[3] = (uint32_t)localsPtr;
38*0a6a1f1dSLionel Sambuc trampOnStack[4] = 0x7d6802a6; /* Lbase: mflr r11 */
39*0a6a1f1dSLionel Sambuc trampOnStack[5] = 0x818b0000; /* lwz r12,0(r11) */
40*0a6a1f1dSLionel Sambuc trampOnStack[6] = 0x7c0803a6; /* mtlr r0 */
41*0a6a1f1dSLionel Sambuc trampOnStack[7] = 0x7d8903a6; /* mtctr r12 */
42*0a6a1f1dSLionel Sambuc trampOnStack[8] = 0x816b0004; /* lwz r11,4(r11) */
43*0a6a1f1dSLionel Sambuc trampOnStack[9] = 0x4e800420; /* bctr */
44*0a6a1f1dSLionel Sambuc
45*0a6a1f1dSLionel Sambuc /* clear instruction cache */
46*0a6a1f1dSLionel Sambuc __clear_cache(trampOnStack, &trampOnStack[10]);
47*0a6a1f1dSLionel Sambuc }
48*0a6a1f1dSLionel Sambuc #endif /* __ppc__ && !defined(__powerpc64__) */
49