1.8.4 SD Card Bootloader Configurations
Bootloader Specific User Configurations
Bootloader Media Type:
Change the Media Type to SDCARD
Bootloader NVM Memory Used:
Specifies the memory peripheral used by bootloader to perform flash operations
The name of the peripheral will vary from device to device
Bootloader Size (Bytes):
Specifies the maximum size of flash required by the bootloader
This size is calculated based on Bootloader type and Memory used
This size will vary from device to device and should always be aligned to device erase unit size
Enable Bootloader Trigger From Firmware:
This Option can be used to Force Trigger bootloader from application firmware after a soft reset. It does so by reserving the specified number of bytes in SRAM from the start of the RAM. The reserved memory is updated by the application with a pre-defined pattern. The bootloader firmware in the bootloader_Trigger() routine, can check the reserved memory for the pre-defined pattern and enter bootloader mode if the pattern matches.
Number Of Bytes To Reserve From Start Of RAM:
This option adds the provided offset to RAM Start address in bootloader linker script.
Application firmware can store some pattern in the reserved bytes region from RAM start for bootloader to check at reset in bootloader_Trigger() function
Application Binary Image Path:
Application binary image file name with path. If only file name is mentioned bootloader will try to open the file from the root directory
Default: image.bin
Can be used to specify custom paths based on requirement
Example: dir1/dir2/app.bin
File System Configurations
Use File System Auto Mount Feature:
Enabled by default when File System Bootloader is added
Media Type:
Change the Media Type to SYS_FS_MEDIA_TYPE_SDCARD
Make FAT File System Read-only:
Enabled by default when File System Bootloader is added as there are no write operations to be done
Enabling this option also saves significant amount of flash memory
Bootloader System Configurations
Application Start Address (Hex):
Start address of the application which will programmed by bootloader
This value is filled by bootloader when its loaded which is equal to the bootloader size. It can be modified as per user need
This value will be used by bootloader to Jump to application at device reset
Bootloader Linker Pre Processor Macros for CORTEX-M based MCUs
Based on the configurations the above linker pre processor macros will be generated in MPLAB X xc32-ld settings
ROM_LENGTH specifies the size of the bootloader