v2.0.0
boot_lock.h
1/*
2 * Copyright (c) 2024 Raspberry Pi (Trading) Ltd.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7#ifndef _HARDWARE_BOOT_LOCK_H
8#define _HARDWARE_BOOT_LOCK_H
9
10#include "pico.h"
11
12// PICO_CONFIG: PARAM_ASSERTIONS_ENABLED_HARDWARE_BOOT_LOCK, Enable/disable assertions in the hardware_boot_lock module, type=bool, default=0, group=hardware_boot_lock
13#ifndef PARAM_ASSERTIONS_ENABLED_HARDWARE_BOOT_LOCK
14#define PARAM_ASSERTIONS_ENABLED_HARDWARE_BOOT_LOCK 0
15#endif
16
17#if NUM_BOOT_LOCKS > 0
18#include "hardware/sync.h"
19#include "hardware/structs/bootram.h"
20
24typedef volatile uint32_t boot_lock_t;
25
32__force_inline static boot_lock_t *boot_lock_instance(uint lock_num) {
33 invalid_params_if(HARDWARE_BOOT_LOCK, lock_num >= NUM_BOOT_LOCKS);
34 return (boot_lock_t *) (BOOTRAM_BASE + BOOTRAM_BOOTLOCK0_OFFSET + lock_num * 4);
35}
36
43__force_inline static uint boot_lock_get_num(boot_lock_t *lock) {
44 invalid_params_if(HARDWARE_BOOT_LOCK, (uint) lock < BOOTRAM_BASE + BOOTRAM_BOOTLOCK0_OFFSET ||
45 (uint) lock >= NUM_BOOT_LOCKS * sizeof(boot_lock_t) + BOOTRAM_BASE + BOOTRAM_BOOTLOCK0_OFFSET ||
46 ((uint) lock - BOOTRAM_BASE + BOOTRAM_BOOTLOCK0_OFFSET) % sizeof(boot_lock_t) != 0);
47 return (uint) (lock - (boot_lock_t *) (BOOTRAM_BASE + BOOTRAM_BOOTLOCK0_OFFSET));
48}
49
55__force_inline static void boot_lock_unsafe_blocking(boot_lock_t *lock) {
56 // Note we don't do a wfe or anything, because by convention these boot_locks are VERY SHORT LIVED and NEVER BLOCK and run
57 // with INTERRUPTS disabled (to ensure that)... therefore nothing on our core could be blocking us, so we just need to wait on another core
58 // anyway which should be finished soon
59 while (__builtin_expect(!*lock, 0)) { // read from bootlock register (tries to acquire the lock)
60 tight_loop_contents();
61 }
62 __mem_fence_acquire();
63}
64
70__force_inline static bool boot_try_lock_unsafe(boot_lock_t *lock) {
71 if (*lock) {
72 __mem_fence_acquire();
73 return true;
74 }
75 return false;
76}
77
83__force_inline static void boot_unlock_unsafe(boot_lock_t *lock) {
84 __mem_fence_release();
85 *lock = 0; // write to bootlock register (release lock)
86}
87
96__force_inline static uint32_t boot_lock_blocking(boot_lock_t *lock) {
97 uint32_t save = save_and_disable_interrupts();
98 boot_lock_unsafe_blocking(lock);
99 return save;
100}
101
107inline static bool is_boot_locked(boot_lock_t *lock) {
108 check_hw_size(boot_lock_t, 4);
109 uint lock_num = boot_lock_get_num(lock);
110 return 0 != (*(io_ro_32 *) (BOOTRAM_BASE + BOOTRAM_BOOTLOCK_STAT_OFFSET) & (1u << lock_num));
111}
112
123__force_inline static void boot_unlock(boot_lock_t *lock, uint32_t saved_irq) {
124 boot_unlock_unsafe(lock);
125 restore_interrupts_from_disabled(saved_irq);
126}
127
136boot_lock_t *boot_lock_init(uint lock_num);
137
141void boot_locks_reset(void);
142
143#endif
144#endif
save_and_disable_interrupts
static __force_inline uint32_t save_and_disable_interrupts(void)
Save and disable interrupts.
Definition: sync.h:206
__mem_fence_release
static __force_inline void __mem_fence_release(void)
Release a memory fence.
Definition: sync.h:189
restore_interrupts_from_disabled
static __force_inline void restore_interrupts_from_disabled(uint32_t status)
Restore interrupts to a specified state with restricted transitions.
Definition: sync.h:249
__mem_fence_acquire
static __force_inline void __mem_fence_acquire(void)
Acquire a memory fence.
Definition: sync.h:173
__force_inline
#define __force_inline
Attribute to force inlining of a function regardless of optimization level.
Definition: compiler.h:125
tight_loop_contents
static __force_inline void tight_loop_contents(void)
No-op function for the body of tight loops.
Definition: platform.h:67
pico.h
sync.h