openblt_flash.cpp

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#include "pch.h"
#include "flash_int.h"
 
extern "C" {
    #include "boot.h"
    #include "flash.h"
}
 
void FlashInit() {
    // Flash already init by ChibiOS
}
 
blt_addr FlashGetUserProgBaseAddress() {
#ifdef STM32H7XX
    return FLASH_BASE + 128 * 1024;
#else // not STM32H7
    return FLASH_BASE + 32 * 1024;
#endif
}
 
blt_bool FlashWrite(blt_addr addr, blt_int32u len, blt_int8u *data) {
    // don't allow overwriting the bootloader
    if (addr < FlashGetUserProgBaseAddress()) {
        return BLT_FALSE;
    }
 
    return (FLASH_RETURN_SUCCESS == intFlashWrite(addr, (const char*)data, len)) ? BLT_TRUE : BLT_FALSE;
 
    return BLT_TRUE;
}
 
blt_bool FlashErase(blt_addr addr, blt_int32u len) {
    // don't allow erasing the bootloader
    if (addr < FlashGetUserProgBaseAddress()) {
        return BLT_FALSE;
    }
 
    if (!intFlashIsErased(addr, len)) {
        return (FLASH_RETURN_SUCCESS == intFlashErase(addr, len)) ? BLT_TRUE : BLT_FALSE;
    }
 
    return BLT_TRUE;
}
 
blt_bool FlashDone() {
    return BLT_TRUE;
}
 
blt_bool FlashWriteChecksum() {
    return BLT_TRUE;
}
 
blt_bool FlashVerifyChecksum() {
    // Naive check: if the first block is blank, there's no code there
    if (intFlashIsErased(FlashGetUserProgBaseAddress(), 4)) {
        return BLT_FALSE;
    }
 
    static const size_t checksumOffset = 0x1C;
 
    // Now do the actual CRC check to ensure we didn't get stuck with a half-written firmware image
    uint8_t* start = reinterpret_cast<uint8_t*>(FlashGetUserProgBaseAddress());
 
    size_t imageSize = *reinterpret_cast<size_t*>(start + checksumOffset + 4);
 
    if (imageSize > 1024 * 1024) {
        // impossibly large size, invalid
        return BLT_FALSE;
    }
 
    // part before checksum+size
    uint32_t calcChecksum = crc32(start, checksumOffset);
    // part after checksum+size
    calcChecksum = crc32inc(start + checksumOffset + 4, calcChecksum, imageSize - (checksumOffset + 4));
 
    uint32_t storedChecksum = *reinterpret_cast<uint32_t*>(start + checksumOffset);
 
    return calcChecksum == storedChecksum ? BLT_TRUE : BLT_FALSE;
}
 
blt_bool isFlashDualBank(void) {
#ifdef STM32F7XX
    // cleared bit indicates dual bank
    return (FLASH->OPTCR & FLASH_OPTCR_nDBANK) == 0 ? BLT_TRUE : BLT_FALSE;
#else
    return BLT_TRUE;
#endif
}