mpu_util.cpp

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/**
 * @file    mpu_util.cpp
 *
 * @date Jul 27, 2014
 * @author Andrey Belomutskiy, (c) 2012-2020
 */
 
#include "pch.h"
 
#include "flash_int.h"
 
static bool isDualBank() {
#ifdef FLASH_OPTCR_nDBANK
    // cleared bit indicates dual bank
    return (FLASH->OPTCR & FLASH_OPTCR_nDBANK) == 0;
#else
    return 0;
#endif
}
 
static uint16_t flashSize() {
    return *reinterpret_cast<const volatile uint16_t*>(FLASHSIZE_BASE);
}
 
enum class DeviceType {
    DualBank1MB,
    DualBank2MB,
    SingleBank1MB,
    SingleBank2MB,
    Unknown
};
 
static DeviceType determineDevice() {
    bool db = isDualBank();
    uint16_t fs = flashSize();
 
    if (db) {
        if (fs == 1024) {
            return DeviceType::DualBank1MB;
        } else if (fs == 2048) {
            return DeviceType::DualBank2MB;
        }
    } else {
        if (fs == 1024) {
            // Unsupported scenario! Not enough space for program plus two config copies
            criticalError("1MB single bank MCU detected: please clear nDBANK option bit and reinstall FW.");
            return DeviceType::SingleBank1MB;
        } else if (fs == 2048) {
            return DeviceType::SingleBank2MB;
        }
    }
 
    criticalError("Unrecognized flash memory layout db=%d, size=%d", db, fs);
    return DeviceType::Unknown;
}
 
bool mcuCanFlashWhileRunning() {
    // Allow flash-while-running if dual bank mode is enabled, and we're a 2MB device (ie, no code located in second bank)
    return determineDevice() == DeviceType::DualBank2MB;
}
 
// See ST AN4826
size_t flashSectorSize(flashsector_t sector) {
    // 1MB devices have 8 sectors per bank
    // 2MB devices have 12 sectors per bank
    // However, the second bank always starts at index 12 (1MB devices have a 4 sector discontinuity between banks)
 
    if (sector >= 12) {
        // The second bank has the same structure as the first
        return flashSectorSize(sector - 12);
    }
 
    // On 1MB devices, sectors 8-11 don't exist, therefore have zero size.
    if (flashSize() == 1024) {
        if (sector > 7 && sector < 12) {
            return 0;
        }
    }
 
    // Pages are twice the size when in single bank mode
    size_t dbMul = isDualBank() ? 1 : 2;
 
    if (sector <= 3)
        return 16 * 1024 * dbMul;
    else if (sector == 4)
        return 64 * 1024 * dbMul;
    else if (sector >= 5)
        return 128 * 1024 * dbMul;
    return 0;
}
 
uintptr_t getFlashAddrFirstCopy() {
    switch (determineDevice()) {
        case DeviceType::DualBank1MB:
            // Sector 18, second to last 128K sector
            return 0x080C0000;
        case DeviceType::SingleBank1MB:
            // Sector 7, last 256K sector
            return 0x080C0000;
        case DeviceType::DualBank2MB: /* falls thru */
        case DeviceType::SingleBank2MB:
#ifdef EFI_FLASH_USE_1500_OF_2MB
            // Right after the first 1.5 megabytes
            // Sector 20 for dual bank
            // Sector 10 for single bank
            return 0x08180000;
#else
            // Start of the second megabyte
            // Sector 12 for dual bank
            // Sector 8 for single bank
            return 0x08100000;
#endif // EFI_FLASH_USE_1500_OF_2MB
        default:
            return 0;
    }
}
 
uintptr_t getFlashAddrSecondCopy() {
    switch (determineDevice()) {
        case DeviceType::DualBank1MB:
            // Sector 19, last 128K sector, 128K after the first copy
            return 0x080E0000;
        case DeviceType::DualBank2MB:
#ifdef EFI_FLASH_USE_1500_OF_2MB
            // Sector 21, 128K after the first copy
            return 0x081A0000;
#else
            // Sector 14, 32K after the first copy
            return 0x08108000;
#endif // EFI_FLASH_USE_1500_OF_2MB
        case DeviceType::SingleBank2MB:
#ifdef EFI_FLASH_USE_1500_OF_2MB
            // Sector 11, 256K after the first copy
            return 0x081C0000;
#else
            // Sector 9, 256K after the first copy
            return 0x08140000;
#endif // EFI_FLASH_USE_1500_OF_2MB
        case DeviceType::SingleBank1MB:
            // We can't fit a second copy in this config, fall thru to failure case
        default:
            return 0;
    }
}
 
/*
Standby for both F4 & F7 works perfectly, with very little current consumption. Downside is that theres a limited amount of pins that can wakeup F7, and only PA0 for F4XX.
Cannot be used for CAN wakeup without hardware modifications.
*/
void stm32_standby() {
    SysTick->CTRL = 0;
    SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;
    PWR->CR1 |= PWR_CR1_PDDS;   // PDDS = use standby mode (not stop mode)
    PWR->CR1 |= PWR_CR1_CSBF;   // Clear standby flag
 
    // Do anything the board wants to prepare for standby mode - enabling wakeup sources!
    boardPrepareForStandby();
 
    __disable_irq();
    __WFI();
}