37 lines
1.0 KiB
C
37 lines
1.0 KiB
C
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// Copyright 2023 Nick Brassel (@tzarc)
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// SPDX-License-Identifier: GPL-2.0-or-later
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#include <hal.h>
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#define BOOTLOADER_MAGIC 0xDEADBEEF
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////////////////////////////////////////////////////////////////////////////////
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// Different signalling for bootloader entry
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// - RAM is cleared on reset, so we can't use the usual __ram0_end__ symbol.
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// - Use backup registers in the RTC peripheral to store the magic value instead.
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static inline void enable_backup_register_access(void) {
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PWR->CR1 |= PWR_CR1_DBP;
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}
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static inline void disable_backup_register_access(void) {
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PWR->CR1 &= ~PWR_CR1_DBP;
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}
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void bootloader_marker_enable(void) {
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enable_backup_register_access();
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RTC->BKP0R = BOOTLOADER_MAGIC;
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disable_backup_register_access();
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}
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bool bootloader_marker_active(void) {
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enable_backup_register_access();
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bool ret = RTC->BKP0R == BOOTLOADER_MAGIC;
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disable_backup_register_access();
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return ret;
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}
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void bootloader_marker_disable(void) {
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enable_backup_register_access();
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RTC->BKP0R = 0;
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disable_backup_register_access();
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}
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