Hello.

I am trying to write a flash loader for the STM32F207 SPI flash.
The debug build was successful and works.

The release build works too, but the read back function in J-Flash app returns garbage.

The problem is with the SEGGER_OPEN_Read function (U32 Addr, U32 numBytes, U8 *pdestbuf). When calling the SEGGER_OPEN_Read function, the argument is numBytes = 0. My code returns -1 (error), because it is not known how many bytes to read from spi-flash, but j-flash does not give any error messages and continues to work.

Calling the SEGGER_OPEN_Read function with the argument numBytes = 0 is a bug, or I misunderstand the "read back" procedure?

I'm use J-Flash V6.94b.

Yes.

Thanks.

Hello.

Are you sure that the "SEGGER_OPEN_Read" function is not called in my project? If you add an infinite loop to a function, j-flash completes the "Read Back" procedure by timeout. Maybe you tested the wrong flash loader.elf file. The "Flashloader.elf" file is located in the archive attached in the previous message in the "Output\Release\Exe" directory.

I tried to use the project you sent, a log file with the result attached to this message. Also, if the "SEGGER_OPEN_Read" function returns -1, j-flash does not return any error messages, as I described earlier. However, when using the method described above in your project, the "numBytes" argument passed to the "SEGGER_OPEN_Read" function is 0x2600. And here I do not understand why in your case numBytes = = 0x2600, and in my case numBytes == 0x00? Maybe there are some additional requirements for writing flash loader?

Thanks.