sillydan1/flashlib

Simple PIC32 flash memory utility library with emulated eeprom access

Flashlib

A flash programming and EEPROM emulation utility library for PIC32MX devices. So far this library only supports the PIC32MX1xx/2xx/5xx 64/100pin devices from datasheet D60001290.

This library assumes you have the xc32-gcc compiler chain installed. If you haven't, you can find it here.

Supported Features

• eeprom_read_word Reads a word from emulated eeprom, if enabled
• eeprom_write_word Writes a word to emulated eeprom, if enabled
• flash_write_word Writes a word to program flash memory
• flash_program_page_offset Read/Modify/Write algorithm to write a page that is offset to the page size. Note, this function will only write a single page. If the provided data is bigger than a page, the additional data will not be written.
• flash_program_page Read/Modify/Write algorithm to write a page to program flash memory. Will return FLASH_NOT_ALIGNED if provided address is not page-aligned
• flash_write_page Writes a page to program flash memory. Note, this will erase whatever's on the page before.
• flash_write_row Writes a row to program flash memory
• flash_erase_page Erases a page of program flash memory
• flash_erase_all_program_memory Erases all of program flash memory - Including emulated eeprom sector. Use with caution. Note, this function is enabled by default but can be disabled to avoid accidents with the DISABLE_ERASE_ALL_PROGRAM_MEM cmake variable
• Custom Protected flash sector support, to avoid situations like bootloaders overriding itself

Use in your CMake projects

Simply add the folder as a subdirectory. Don't forget to set the compiler to the xc32-gcc compiler.

add_subdirectory(path/to/flashlib)
...
target_link_libraries(target flashlib)

You can now include the flashlib.h file and use the functions defined therein.

EEPROM Emulation

You can specify at compile-time what section of flash you want to dedicate to eeprom emulation. The following cmake variables are available:

-DENABLE_EEPROM_EMU              # Enabling compilation of eeprom emulation
-DEEPROM_SECTOR_START=<ksegaddr> # Determines start address for eeprom dedicated flash memory
-DEEPROM_SECTOR_END=<ksegaddr>   # Determines end address for eeprom dedicated flash memory

The start and end sector variables are required if you want to use eeprom emulation. If ENABLE_EEPROM_EMU is not defined, no need to define the start and end sectors. Note that all flash addresses should be in kernel-space (KSEG0/1). Below is an example usage:

cmake -DENABLE_EEPROM_EMU=1 -DEEPROM_SECTOR_START=0x9D070000 -DEEPROM_SECTOR_END=0x9D07FFFF ..

Flash programming support

If your MCU supports double word programming (not all do) you can compile with support for that with the ENABLE_DOUBLEWORD_PROGRAMMING cmake flag variable.

Protected Sector Support

You can protect a segment of flash, such that the library will refuse to write to addresses within that segment. Use these cmake variables to determine your protected segment:

-DPROTECTED_FLASH_SECTOR_FROM=<ksegaddr> # Determines start address for flash protection
-DPROTECTED_FLASH_SECTOR_TO=<ksegaddr> # Determines end address for flash protection

Contribute

If you have any additions you want submitted, feel free to open up a pull request or issue. Make sure to add yourself in the list of authors in the appropriate file(s).

Notes

CMake tries to check if the provided compiler i "valid", but xc32-gcc does not support the standard -rdynamic flag. This check can be sidestepped by providing cmake with the -DCMAKE_C_COMPILER_WORKS=1 flag.