How to add or remove boot header for XIP targets#

The MCUXpresso SDK for i.MX RT1015 provides flexspi_nor_debug and flexspi_nor_release targets for each example and/or demo which supports XIP (eXecute-In-Place). These two targets add XIP_BOOT_HEADER to the image by default. Because of this, ROM can boot and run this image directly on external flash.

Macros for the boot leader:

The following three macros are added in flexspi_nor targets to support XIP, as described in Table 1.

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|XIP_EXTERNAL_FLASH|1: Exclude the code which changes the clock of FLEXSPI.| |0: Make no changes.| |XIP_BOOT_HEADER_ENABLE|1: Add FLEXSPI configuration block, image vector table, boot data, and device configuration data (optional) to the image by default.| |0: Add nothing to the image by default.| |XIP_BOOT_HEADER_DCD_ENABLE|1: Add device configuration data to the image.| |0: Do NOT add device configuration data to the image.|

Table 2 shows the different effect on the built image with a different combination of these macros.

	XIP_BOOT_HEADER_DCD_ENABLE=1	XIP_BOOT_HEADER_DCD_ENABLE=0
XIP_EXTERNAL_FLASH=1	XIP_BOOT_HEADER_ENABLE=1	- Can be programmed to `qspiflash` by IDE and can run after POR reset if `qspiflash` is the boot source.

SDRAM will be initialized. | - Can be programmed to qspiflash by IDE, and can run after POR reset if qspiflash is the boot source.
SDRAM will NOT be initialized. |XIP_BOOT_HEADER_ENABLE=0| - CANNOT run after POR reset if it is programmed by IDE, even if qspiflash is the boot source. |XIP_EXTERNAL_FLASH=0| - This image CANNOT complete because when this macro is set to 0, it includes the code which changes the clock for FLEXSPI.

Where to change the macros for each toolchain in MCUXpresso SDK?

Take hello_world as an example:

IAR
MDK
ARMGCC

Change the configuration in CMakeLists.txt.
MCUX