1 /*
2 * Copyright (c) 2022, Carlo Caione <ccaione@baylibre.com>
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include <zephyr/arch/cpu.h>
8 #include <zephyr/linker/sections.h>
9
10 #include <zephyr/arch/common/pm_s2ram.h>
11
12 #define MAGIC (0xDABBAD00)
13
14 /**
15 * CPU context for S2RAM
16 */
17 __noinit _cpu_context_t _cpu_context;
18
19 #ifndef CONFIG_PM_S2RAM_CUSTOM_MARKING
20 /**
21 * S2RAM Marker
22 */
23 static __noinit uint32_t marker;
24
pm_s2ram_mark_set(void)25 void __attribute__((naked)) pm_s2ram_mark_set(void)
26 {
27 __asm__ volatile(
28 /* Set the marker to MAGIC value */
29 "str %[_magic_val], [%[_marker]]\n"
30
31 "bx lr\n"
32 :
33 : [_magic_val] "r"(MAGIC), [_marker] "r"(&marker)
34 : "r1", "r4", "memory");
35 }
36
pm_s2ram_mark_check_and_clear(void)37 bool __attribute__((naked)) pm_s2ram_mark_check_and_clear(void)
38 {
39 __asm__ volatile(
40 /* Set return value to 0 */
41 "mov r0, #0\n"
42
43 /* Check the marker */
44 "ldr r3, [%[_marker]]\n"
45 "cmp r3, %[_magic_val]\n"
46 "bne exit\n"
47
48 /*
49 * Reset the marker
50 */
51 "str r0, [%[_marker]]\n"
52
53 /*
54 * Set return value to 1
55 */
56 "mov r0, #1\n"
57
58 "exit:\n"
59 "bx lr\n"
60 :
61 : [_magic_val] "r"(MAGIC), [_marker] "r"(&marker)
62 : "r0", "r1", "r3", "r4", "memory");
63 }
64
65 #endif /* CONFIG_PM_S2RAM_CUSTOM_MARKING */
66
