From 0d614fc669efc91b8dd25241d5775460a6fd7f4a Mon Sep 17 00:00:00 2001
From: Daniele Lacamera <dan@danielinux.net>
Date: Thu, 16 Nov 2023 09:56:44 +0100
Subject: [PATCH] Added custom DCD for i.mx-RT10XX

---
 arch.mk         |  4 ++++
 docs/Targets.md | 14 ++++++++++++++
 hal/imx_rt.c    | 13 +++++++++++--
 hal/imx_rt.ld   |  1 +
 tools/config.mk |  4 +++-
 5 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/arch.mk b/arch.mk
index 75fb67cf0..4791ba6bc 100644
--- a/arch.mk
+++ b/arch.mk
@@ -781,5 +781,9 @@ ifeq ($(DEBUG_UART),1)
   CFLAGS+=-DDEBUG_UART
 endif
 
+ifeq ($(NXP_CUSTOM_DCD),1)
+  CFLAGS+=-DNXP_CUSTOM_DCD
+endif
+
 CFLAGS+=-DWOLFBOOT_ARCH_$(ARCH)
 CFLAGS+=-DTARGET_$(TARGET)
diff --git a/docs/Targets.md b/docs/Targets.md
index 5adfaba66..5a32dc354 100644
--- a/docs/Targets.md
+++ b/docs/Targets.md
@@ -1164,6 +1164,20 @@ You can also get the SDK and CMSIS bundles using these repositories:
 * https://github.com/nxp-mcuxpresso/CMSIS_5
 Use MCUXSDK=1 with this option, since the pack paths are different.
 
+### Custom Device Configuration Data (DCD)
+
+On iMX-RT10xx it is possible to load a custom DCD section from an external
+source file. A customized DCD section should be declared within the `.dcd_data`
+section, e.g.:
+
+
+`const uint8_t __attribute__((section(".dcd_data"))) dcd_data[] = { /* ... */ };`
+
+
+If an external `.dcd_data` section is provided, the option `NXP_CUSTOM_DCD=1` must
+be added to the configuration.
+
+
 ### Testing Update
 
 First make the update partition, pre-triggered for update
diff --git a/hal/imx_rt.c b/hal/imx_rt.c
index 3f7e1e8f2..4dae197ce 100644
--- a/hal/imx_rt.c
+++ b/hal/imx_rt.c
@@ -568,14 +568,23 @@ const BOOT_DATA_T __attribute__((section(".boot_data"))) boot_data = {
     0xFFFFFFFF                  /* empty - extra data word */
 };
 
-const uint8_t dcd_data[1] = {0};
+
 extern void isr_reset(void);
+extern const uint32_t __dcd_data_start;
+const uint32_t dcd_data_addr = (uint32_t) &__dcd_data_start;
+
+#ifndef NXP_CUSTOM_DCD
+/* If a DCD section is populated, it should be mapped to the .dcd_data section.
+ * By default, provide an empty section.
+ */
+const uint8_t __attribute__((section(".dcd_data"))) dcd_data[sizeof(uint32_t)] = { 0 };
+#endif
 
 const ivt __attribute__((section(".image_vt"))) image_vector_table = {
     IVT_HEADER,                         /* IVT Header */
     (uint32_t)isr_reset,                /* Image Entry Function */
     IVT_RSVD,                           /* Reserved = 0 */
-    (uint32_t)dcd_data,                 /* Address where DCD information is stored */
+    (uint32_t)dcd_data_addr,            /* Address where DCD information is stored */
     (uint32_t)&boot_data,               /* Address where BOOT Data Structure is stored */
     (uint32_t)&image_vector_table,      /* Pointer to IVT Self (absolute address */
     (uint32_t)CSF_ADDRESS,              /* Address where CSF file is stored */
diff --git a/hal/imx_rt.ld b/hal/imx_rt.ld
index f00d88461..af834714b 100644
--- a/hal/imx_rt.ld
+++ b/hal/imx_rt.ld
@@ -15,6 +15,7 @@ SECTIONS
         . = ORIGIN(FLASH) + 0x1000;
         KEEP(*(.image_vt))
         KEEP(*(.boot_data))
+        __dcd_data_start = .;
         KEEP(*(.dcd_data))
         . = ORIGIN(FLASH) + 0x2000;
         KEEP(*(.isr_vector))
diff --git a/tools/config.mk b/tools/config.mk
index e7706fb30..edd053ef8 100644
--- a/tools/config.mk
+++ b/tools/config.mk
@@ -10,6 +10,7 @@ ifeq ($(ARCH),)
   MCUXPRESSO_DRIVERS?=$(MCUXPRESSO)/devices/MK64F12
   MCUXPRESSO_CMSIS?=$(PWD)/CMSIS_5/CMSIS
   FREEDOM_E_SDK?=$(HOME)/src/freedom-e-sdk
+  NXP_CUSTOM_DCD=0
   STM32CUBE?=$(HOME)/STM32Cube/Repository/STM32Cube_FW_WB_V1.3.0
   CYPRESS_PDL?=$(HOME)/src/psoc6pdl
   CYPRESS_TARGET_LIB?=$(HOME)/src/TARGET_CY8CKIT-062S2-43012
@@ -95,4 +96,5 @@ CONFIG_VARS:= ARCH TARGET SIGN HASH MCUXSDK MCUXPRESSO MCUXPRESSO_CPU MCUXPRESSO
 	LMS_LEVELS LMS_HEIGHT LMS_WINTERNITZ \
 	WOLFBOOT_UNIVERSAL_KEYSTORE \
 	XMSS_PARAMS \
-	ELF
+	ELF \
+	NXP_CUSTOM_DCD