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/* ===--- Begin imxrt-boot-header.x ---===
* This extra content is injected into the linker script depending on the
* runtime configuration.
*/
/* If you're ever playing with the boot ROM copy, this is your image size.
*
* Note that it depends on the section layout! Need to represent contiguous
* sections starting from the boot header.
*/
__image_size = SIZEOF(.boot) + SIZEOF(.vector_table) + SIZEOF(.xip) + SIZEOF(.text) + SIZEOF(.rodata);
/* END TODO */
EXTERN(FLEXSPI_CONFIGURATION_BLOCK);
/* # Sections */
SECTIONS
{
/* Boot header for serial NOR FlexSPI XIP.
*
* It's 'XIP' in that it starts executing instructions
* from flash immediately out of reset. The runtime then
* manually copies instructions (data, etc.), and we jump
* to that. After that jump, we're no longer XIP.
*
* The i.MX RT boot ROM also supports a way to copy the
* application image by changing the boot data configuration.
* Specifically, point the 'start of image' to somewhere other
* than the start of flash, and specify how many bytes to copy.
* The boot ROM copies the image, then jumps to the vector table.
* There's a catch: the boot ROM copies the first 8K from the
* start of flash too. This represents the entire boot header,
* including the FCB, IVT, and boot data. (NXP docs say that the
* initial load region is 4K; my testing shows that it's 8K, and
* this aligns with observations of others.) If you ever want to
* try this, make sure you're specifing the VMA and LMA of the
* boot head section to represent this 8K relocation.
*/
.boot ORIGIN(FLASH):
{
. += __fcb_offset; /* Changes based on the chip */
KEEP(*(.fcb));
. = ORIGIN(FLASH) + 0x1000;
/* ------------------
* Image vector table
* ------------------
*
* Not to be confused with the ARM vector table. This tells the boot ROM
* where to find the boot data and (eventual) first vector table.
* The IVT needs to reside right here.
*/
__ivt = .;
LONG(0x402000D1); /* Header, magic number */
LONG(__sivector_table); /* Address of the vectors table */
LONG(0x00000000); /* RESERVED */
LONG(__dcd); /* Device Configuration Data */
LONG(__boot_data); /* Address to boot data */
LONG(__ivt); /* Self reference */
LONG(0x00000000); /* Command Sequence File (unused) */
LONG(0x00000000); /* RESERVED */
/* ---------
* Boot data
* ---------
*/
__boot_data = .;
LONG(ORIGIN(FLASH)); /* Start of image */
LONG(__image_size); /* Length of image */
LONG(0x00000000); /* Plugin flag (unused) */
LONG(0xDEADBEEF); /* Dummy to align boot data to 16 bytes */
. = ALIGN(4);
__dcd_start = .;
KEEP(*(.dcd)); /* Device Configuration Data */
__dcd_end = .;
__dcd = ((__dcd_end - __dcd_start) > 0) ? __dcd_start : ABSOLUTE(0);
*(.Reset); /* Jam the imxrt-rt reset handler into flash. */
*(.__pre_init); /* Also jam the pre-init function, since we need it to run before instructions are placed. */
. = ORIGIN(FLASH) + 0x2000; /* Reserve the remaining 8K as a convenience for a non-XIP boot. */
} > FLASH
}
/* ===--- End imxrt-boot-header.x ---=== */
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