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 #if defined(__APPLE__) && defined(__MACH__)
38 "_nlr_push: \n"
39 ".global _nlr_push \n"
40 #else
41 "nlr_push: \n"
42 ".global nlr_push \n"
43 #endif
44 "mov x9, sp \n"
45 "stp lr, x9, [x0, #16]\n" // 16 == offsetof(nlr_buf_t, regs)
46 "stp x19, x20, [x0, #32]\n"
47 "stp x21, x22, [x0, #48]\n"
48 "stp x23, x24, [x0, #64]\n"
49 "stp x25, x26, [x0, #80]\n"
50 "stp x27, x28, [x0, #96]\n"
51 "str x29, [x0, #112]\n"
52 #if defined(__APPLE__) && defined(__MACH__)
53 "b _nlr_push_tail \n" // do the rest in C
54 #else
55 "b nlr_push_tail \n" // do the rest in C
56 #endif
57 );
58
nlr_jump(void * val)59 NORETURN void nlr_jump(void *val) {
60 MP_NLR_JUMP_HEAD(val, top)
61
62 MP_STATIC_ASSERT(offsetof(nlr_buf_t, regs) == 16); // asm assumes it
63
64 __asm volatile (
65 "ldr x29, [%0, #112]\n"
66 "ldp x27, x28, [%0, #96]\n"
67 "ldp x25, x26, [%0, #80]\n"
68 "ldp x23, x24, [%0, #64]\n"
69 "ldp x21, x22, [%0, #48]\n"
70 "ldp x19, x20, [%0, #32]\n"
71 "ldp lr, x9, [%0, #16]\n" // 16 == offsetof(nlr_buf_t, regs)
72 "mov sp, x9 \n"
73 "mov x0, #1 \n" // non-local return
74 "ret \n"
75 :
76 : "r" (top)
77 :
78 );
79
80 MP_UNREACHABLE
81 }
82
83 #endif // MICROPY_NLR_AARCH64
84