Helmut Stettmaier

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8 years, 10 months ago.

modify mbed's treating internal flash memory?

Hello, I'm new to mbed, I own an OM11043 and I kindly ask for some help. These 3 questions are closely related and so I do not want to post them separately.

Avoid program to be stored in mbed drive

/handbook/How-mbed-works: "If there is no binary on the mbed disk, the target microcontroller will simply be kept held in reset." Can this be avoided? I would like to load the released software and then delete it from the external flash store to save space and for simplicity reasons. "Released" still means that the software may be changed by others (this is an intended use of the device). So the OM11043 shall run, when there is no software on the disk and it shall still be easily possible (usind mbed) to change the software.

Avoid clearing the whole flash when loading a program

/users/okano/notebook/iap-in-application-programming-internal-flash-eras/: "...because when you load new executable to the mbed (resetting mbed after new code stored in the mbed), the all (chip-internal) flash contents will be cleared and...". Can this be avoided? There are some (large) data resources to be placed in the flash memory which should not always be cleared and reloaded.

Extra data in flash memory - best practice?

I want to place some data resources (parameter tables, speech and sound clips) into the flash; I do not want to place them in the external storage to avoid overhead. The internal flash of the 1768 really is large enough for this. Which is the best suited file format for such data?

  • Integrating it into any source code of the software is, I think, by far not optimal.
  • .bin: As I have learned so far .bin files do not specify the address(es) where the stuff is to be flashed at. Is this true? This would .bin render useless for the explained purpose as the data are to be written into the upper parts of the flash memeory.
  • .hex files could work, but 350kB speech clips could become a bit bulky? Are there other possibilities?

Thank you in advance and kind regards, Helmut

1 Answer

Robert Spilleboudt
8 years, 10 months ago.

Questions 1 and 2 : answer NO : this is how the loader works
Question 3: integrating in the source file or read https://developer.mbed.org/users/okano/code/IAP_internal_flash_write/
My own sound files are coded as WAV, not compressed, this is really too big for the internal flash. I use a SD card .