soc: rp2350: add IMAGE_DEF using rom_start linker script

Use this approach for a simpler flow and to make relocation of images
into RAM easier.

Also do not force-select CONFIG_XIP (which is a default anyway), since
RP2350 can boot from SRAM.

Signed-off-by: Dmitrii Sharshakov <[email protected]>

Author: dsseng

soc/raspberrypi/rpi_pico/rp2350/CMakeLists.txt

@@ -7,4 +7,7 @@ zephyr_library_sources(soc.c)
 
 zephyr_include_directories(.)
 
-set(SOC_LINKER_SCRIPT ${CMAKE_CURRENT_SOURCE_DIR}/linker.ld CACHE INTERNAL "")
+# Add the image definition block if required
+zephyr_linker_sources(ROM_START rom_start.ld)
+
+set(SOC_LINKER_SCRIPT ${ZEPHYR_BASE}/include/zephyr/arch/arm/cortex_m/scripts/linker.ld CACHE INTERNAL "")

soc/raspberrypi/rpi_pico/rp2350/Kconfig

@@ -7,7 +7,6 @@ config SOC_SERIES_RP2350
 	select HAS_RPI_PICO
 	select HAS_SEGGER_RTT if ZEPHYR_SEGGER_MODULE
 	select SOC_RESET_HOOK
-	select XIP
 
 config SOC_RP2350A_M33
 	select ARM
@@ -31,7 +30,7 @@ config SOC_RP2350B_M33
 
 config RP2_REQUIRES_IMAGE_DEFINITION_BLOCK
 	bool
-	default y if FLASH_LOAD_OFFSET = 0x100
+	default y
 	# Currently the IDF only supports using the Cortex-M33 cores. Enforce
 	# this at build configuration time.
 	depends on SOC_SERIES_RP2350 && CPU_CORTEX_M33

soc/raspberrypi/rpi_pico/rp2350/linker.ld

@@ -0,0 +1,17 @@
+/* rom_start.ld - additional data to append at the ROM start */
+
+/*
+ * Copyright (c) 2024 Andrew Featherstone
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#if CONFIG_RP2_REQUIRES_IMAGE_DEFINITION_BLOCK
+LONG(0xffffded3) /* PICOBIN_BLOCK_MARKER_START */
+LONG(0x10210142) /* IMAGE_DEF Item */
+LONG(0x00000203) /* VECTOR_TABLE Item */
+LONG(ABSOLUTE(_vector_start)) /* - Address of the vector table in flash */
+LONG(0x000003ff) /* Last Item in Block */
+LONG(0x00000000) /* End of block loop */
+LONG(0xab123579) /* PICOBIN_BLOCK_MARKER_END */
+#endif /* CONFIG_RP2_REQUIRES_IMAGE_DEFINITION_BLOCK */