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Visitor II
September 18, 2025
Question

ROM Bootloader Get Checksum command fails

  • September 18, 2025
  • 1 reply
  • 283 views

STM32G473 via SPI

 

I have most of the other commands working, but the Get Checksum command (0xA1) fails to return an ACK when I send the CRC init value.

 

I am using the default CRC configuration:

#define DEFAULT_CRC32_POLY 0x04C11DB7U

#define DEFAULT_CRC_INITVALUE 0xFFFFFFFFU

 

It accepts the command, start address, memory size, and polynomial, then fails on the init value.

I haven't found any documentation that indicates what init value is accepted on this MCU, but I do find it hard to believe it does not accept the default init value from the HAL itself.

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    1 reply

    Super User
    September 18, 2025

    Does it NACK?

    Can you show the exact bytes you send in each step in some sort of log?

     

    Initialization value should ACK regardless of if it can be changed.

    TDK_0-1758212882823.png

     

    JBill.10Author
    Visitor II
    September 22, 2025

    It does not respond with a NACK, I just keep getting 0xA5 until my loop gives up after 255 tries.

    It looks like the actual CRC responds as I send the init value.

    I would have pasted the log file but the forum complains that I cannot include that much text and it does not accept the HTML table element.  This has all been very helpful ST, thanks.