1/*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2021 Yonatan Goldschmidt
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27#include "py/mpstate.h" // needed for NLR defs
28
29#if MICROPY_NLR_AARCH64
30
31// AArch64 callee-saved registers are x19-x29.
32// https://en.wikipedia.org/wiki/Calling_convention#ARM_(A64)
33
34// Implemented purely as inline assembly; inside a function, we have to deal with undoing the prologue, restoring
35// SP and LR. This way, we don't.
36__asm(
37 "nlr_push: \n"
38 ".global nlr_push \n"
39 "mov x9, sp \n"
40 "stp lr, x9, [x0, #16]\n" // 16 == offsetof(nlr_buf_t, regs)
41 "stp x19, x20, [x0, #32]\n"
42 "stp x21, x22, [x0, #48]\n"
43 "stp x23, x24, [x0, #64]\n"
44 "stp x25, x26, [x0, #80]\n"
45 "stp x27, x28, [x0, #96]\n"
46 "str x29, [x0, #112]\n"
47 "b nlr_push_tail \n" // do the rest in C
48 );
49
50NORETURN void nlr_jump(void *val) {
51 MP_NLR_JUMP_HEAD(val, top)
52
53 MP_STATIC_ASSERT(offsetof(nlr_buf_t, regs) == 16); // asm assumes it
54
55 __asm volatile (
56 "ldr x29, [%0, #112]\n"
57 "ldp x27, x28, [%0, #96]\n"
58 "ldp x25, x26, [%0, #80]\n"
59 "ldp x23, x24, [%0, #64]\n"
60 "ldp x21, x22, [%0, #48]\n"
61 "ldp x19, x20, [%0, #32]\n"
62 "ldp lr, x9, [%0, #16]\n" // 16 == offsetof(nlr_buf_t, regs)
63 "mov sp, x9 \n"
64 "mov x0, #1 \n" // non-local return
65 "ret \n"
66 :
67 : "r" (top)
68 :
69 );
70
71 MP_UNREACHABLE
72}
73
74#endif // MICROPY_NLR_AARCH64
75