Support RT1180 family

The 1180 family uses a different boot header than previous families. The
header is generated to support the default configuration where hash and
signature errors are ignored.

The XIP `__pre_init` strategy is still used, more for ease of getting
something running than because of any known problems with the boot ROM's
implementation of loading images to different memories.

The boot ROM for the 1180 does not appear to allow the entry point to
lie outside the (loaded or execute-in-place) image, so a new `.xip`
section is added after the vector table to put the address inside the
image while keeping VMA=LMA. This could cause problems for tools that
manipulate binaries based on section names.

1 files changed, 12 insertions, 3 deletions

diff --git a/src/host/imxrt-link.x b/src/host/imxrt-link.x
index 6c28f99..a389325 100644
--- a/src/host/imxrt-link.x
+++ b/src/host/imxrt-link.x
@@ -48,6 +48,7 @@ SECTIONS
 
   .vector_table : ALIGN(1024)
   {
+    FILL(0xff);
     __vector_table = .;
     __svector_table = .;
 
@@ -68,13 +69,19 @@ SECTIONS
   } > REGION_VTABLE AT> REGION_LOAD_VTABLE
   __sivector_table = LOADADDR(.vector_table);
 
+  /* This section guarantees VMA = LMA to allow the execute-in-place entry point to be inside the image. */
+  .xip :
+  {
+    /* Included here if not otherwise included in the boot header. */
+    *(.Reset);
+    *(.__pre_init);
+  } > REGION_LOAD_TEXT
+
   .text :
   {
+    FILL(0xff);
     __stext = .;
     *(.text .text.*);
-    /* Included in .text if not otherwise included in the boot header. */
-    *(.Reset);
-    *(.__pre_init);
     /* The HardFaultTrampoline uses the `b` instruction to enter `HardFault`,
        so must be placed close to it. */
     *(.HardFaultTrampoline);
@@ -86,6 +93,7 @@ SECTIONS
 
   .rodata : ALIGN(4)
   {
+    FILL(0xff);
     . = ALIGN(4);
     __srodata = .;
     *(.rodata .rodata.*);
@@ -100,6 +108,7 @@ SECTIONS
 
   .data : ALIGN(4)
   {
+    FILL(0xff);
     . = ALIGN(4);
     __sdata = .;
     *(.data .data.*);