trampoline.S revision 1.1
1 1.1 mrg /* libgcc routines for RL78 2 1.1 mrg Copyright (C) 2011-2013 Free Software Foundation, Inc. 3 1.1 mrg Contributed by Red Hat. 4 1.1 mrg 5 1.1 mrg This file is part of GCC. 6 1.1 mrg 7 1.1 mrg GCC is free software; you can redistribute it and/or modify it 8 1.1 mrg under the terms of the GNU General Public License as published 9 1.1 mrg by the Free Software Foundation; either version 3, or (at your 10 1.1 mrg option) any later version. 11 1.1 mrg 12 1.1 mrg GCC is distributed in the hope that it will be useful, but WITHOUT 13 1.1 mrg ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14 1.1 mrg or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public 15 1.1 mrg License for more details. 16 1.1 mrg 17 1.1 mrg Under Section 7 of GPL version 3, you are granted additional 18 1.1 mrg permissions described in the GCC Runtime Library Exception, version 19 1.1 mrg 3.1, as published by the Free Software Foundation. 20 1.1 mrg 21 1.1 mrg You should have received a copy of the GNU General Public License and 22 1.1 mrg a copy of the GCC Runtime Library Exception along with this program; 23 1.1 mrg see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 1.1 mrg <http://www.gnu.org/licenses/>. */ 25 1.1 mrg 26 1.1 mrg /* RL78 Trampoline support 27 1.1 mrg 28 1.1 mrg Since the RL78's RAM is not in the first 64k, we cannot "just" use a 29 1.1 mrg function pointer to point to a trampoline on the stack. So, we 30 1.1 mrg create N fixed trampolines that read from an array, and allocate 31 1.1 mrg them as needed. 32 1.1 mrg 33 1.1 mrg */ 34 1.1 mrg 35 1.1 mrg r8 = 0xffef0 36 1.1 mrg r10 = 0xffef2 37 1.1 mrg r14 = 0xffef6 38 1.1 mrg 39 1.1 mrg .data 40 1.1 mrg .p2align 1 41 1.1 mrg trampoline_array: 42 1.1 mrg 43 1.1 mrg .macro stub n 44 1.1 mrg 45 1.1 mrg .text 46 1.1 mrg trampoline_\n: 47 1.1 mrg .type trampoline_\n, @function 48 1.1 mrg movw ax, !trampoline_chain_\n 49 1.1 mrg movw r14, ax 50 1.1 mrg movw ax, !trampoline_addr_\n 51 1.1 mrg br ax 52 1.1 mrg .size trampoline_\n, .-trampoline_\n 53 1.1 mrg 54 1.1 mrg .data 55 1.1 mrg trampoline_frame_\n: 56 1.1 mrg .short 0 57 1.1 mrg trampoline_stub_\n: 58 1.1 mrg .short trampoline_\n 59 1.1 mrg trampoline_chain_\n: 60 1.1 mrg .short 0 61 1.1 mrg trampoline_addr_\n: 62 1.1 mrg .short 0 63 1.1 mrg 64 1.1 mrg #define TO_FRAME 0 65 1.1 mrg #define TO_STUB 2 66 1.1 mrg #define TO_CHAIN 4 67 1.1 mrg #define TO_ADDR 6 68 1.1 mrg #define TO_SIZE 8 69 1.1 mrg 70 1.1 mrg .endm 71 1.1 mrg 72 1.1 mrg stub 0 73 1.1 mrg stub 1 74 1.1 mrg stub 2 75 1.1 mrg stub 3 76 1.1 mrg stub 4 77 1.1 mrg stub 5 78 1.1 mrg 79 1.1 mrg trampoline_array_end: 80 1.1 mrg 81 1.1 mrg /* Given the function pointer in R8 and the static chain 82 1.1 mrg pointer in R10, allocate a trampoline and return its address in 83 1.1 mrg R8. */ 84 1.1 mrg 85 1.1 mrg .text 86 1.1 mrg .global ___trampoline_init 87 1.1 mrg .type ___trampoline_init, @function 88 1.1 mrg ___trampoline_init: 89 1.1 mrg 90 1.1 mrg movw hl, #trampoline_array 91 1.1 mrg 1: 92 1.1 mrg movw ax, [hl + TO_ADDR] 93 1.1 mrg cmpw ax, #0 94 1.1 mrg bz $2f 95 1.1 mrg 96 1.1 mrg movw ax, hl 97 1.1 mrg addw ax, #TO_SIZE 98 1.1 mrg movw hl, ax 99 1.1 mrg cmpw ax, #trampoline_array_end 100 1.1 mrg bnz $1b 101 1.1 mrg brk ; no more slots? 102 1.1 mrg 103 1.1 mrg 2: movw ax, r8 104 1.1 mrg movw [hl + TO_ADDR], ax 105 1.1 mrg movw ax, r10 106 1.1 mrg movw [hl + TO_CHAIN], ax 107 1.1 mrg movw ax, sp 108 1.1 mrg movw [hl + TO_FRAME], ax 109 1.1 mrg 110 1.1 mrg movw ax, [hl + TO_STUB] 111 1.1 mrg movw r8, ax 112 1.1 mrg 113 1.1 mrg ret 114 1.1 mrg .size ___trampoline_init, . - ___trampoline_init 115 1.1 mrg 116 1.1 mrg .global ___trampoline_uninit 117 1.1 mrg .type ___trampoline_uninit, @function 118 1.1 mrg ___trampoline_uninit: 119 1.1 mrg movw hl, #trampoline_array 120 1.1 mrg movw ax, sp 121 1.1 mrg movw bc, ax 122 1.1 mrg 1: 123 1.1 mrg movw ax, [hl + TO_FRAME] 124 1.1 mrg cmpw ax, bc 125 1.1 mrg bc $2f 126 1.1 mrg 127 1.1 mrg clrw ax 128 1.1 mrg movw [hl + TO_ADDR], ax 129 1.1 mrg 130 1.1 mrg 2: 131 1.1 mrg movw ax, hl 132 1.1 mrg addw ax, #TO_SIZE 133 1.1 mrg movw hl, ax 134 1.1 mrg cmpw ax, #trampoline_array_end 135 1.1 mrg bnz $1b 136 1.1 mrg 137 1.1 mrg ret 138 1.1 mrg .size ___trampoline_uninit, . - ___trampoline_uninit 139
Indexes created Tue Aug 04 00:24:20 UTC 2026