fw_info: Change allowed offsets for firmware info struct

Since the vector table of nRF54LX series is larger than before using it
is nice to have an offset between `0x400` and `0x800` to store `fw_info`
in to ensure you can tightly pack your application together with
firmware info. One downside of this is that this new offset is not
supported in any older version of NSIB.

Signed-off-by: Mateusz Michalek <[email protected]>

Author: michalek-no

doc/nrf/libraries/security/bootloader/fw_info.rst

@@ -17,10 +17,10 @@ Purpose
 The purpose of the firmware information is to allow other images such as bootloaders, or infrastructure such as firmware servers, to gain information about the firmware image.
 
 The firmware information structure has a 12-byte magic header and a verified binary layout to ensure that the format is portable and identifiable.
-It must be located at one of the following offsets from the start of the image: 0x0, 0x200, 0x400, 0x800, 0x1000.
+It must be located at one of the following offsets from the start of the image: 0x0, 0x200, 0x400, 0x600, 0x800, 0xe00, 0x1000.
 The reason that the structure is not located at 0x00 is that this can be problematic in some use cases, such as when the vector table must be located at 0x00.
 
-These rules make it simple to retrieve the information by checking for each possible offset (0x0, 0x200, 0x400, 0x800, 0x1000) if the first 12 bytes match the magic value.
+These rules make it simple to retrieve the information by checking for each possible offset (0x0, 0x200, 0x400, 0x600, 0x800, 0xe00, 0x1000) if the first 12 bytes match the magic value.
 If they do, the information can be retrieved according to the definition in :c:struct:`fw_info`.
 
 Information structure

include/fw_info.h

@@ -156,12 +156,14 @@ BUILD_ASSERT(ARRAY_SIZE(fw_info_allowed_offsets) == FW_INFO_OFFSET_COUNT,
  */
 
 /* Build time check of CONFIG_FW_INFO_OFFSET. */
-#if (FW_INFO_OFFSET_COUNT != 5) \
+#if (FW_INFO_OFFSET_COUNT != 7) \
 			|| ((FW_INFO_CURRENT_OFFSET) != (FW_INFO_OFFSET0) && \
 			(FW_INFO_CURRENT_OFFSET) != (FW_INFO_OFFSET1) && \
 			(FW_INFO_CURRENT_OFFSET) != (FW_INFO_OFFSET2) && \
 			(FW_INFO_CURRENT_OFFSET) != (FW_INFO_OFFSET3) && \
-			(FW_INFO_CURRENT_OFFSET) != (FW_INFO_OFFSET4))
+			(FW_INFO_CURRENT_OFFSET) != (FW_INFO_OFFSET4) && \
+			(FW_INFO_CURRENT_OFFSET) != (FW_INFO_OFFSET5) && \
+			(FW_INFO_CURRENT_OFFSET) != (FW_INFO_OFFSET6))
 	#error FW_INFO_OFFSET not set to one of the allowed values.
 #endif
 

include/fw_info_bare.h

@@ -24,9 +24,11 @@ extern "C" {
 #define FW_INFO_OFFSET0 0x0
 #define FW_INFO_OFFSET1 0x200
 #define FW_INFO_OFFSET2 0x400
-#define FW_INFO_OFFSET3 0x800
-#define FW_INFO_OFFSET4 0x1000
-#define FW_INFO_OFFSET_COUNT 5
+#define FW_INFO_OFFSET3 0x600
+#define FW_INFO_OFFSET4 0x800
+#define FW_INFO_OFFSET5 0xe00
+#define FW_INFO_OFFSET6 0x1000
+#define FW_INFO_OFFSET_COUNT 7
 
 /**
  * This struct serves as a header before an EXT_API.
@@ -192,7 +194,8 @@ static inline const struct fw_info *fw_info_check(uint32_t fw_info_addr)
 static const uint32_t fw_info_allowed_offsets[] = {
 					FW_INFO_OFFSET0, FW_INFO_OFFSET1,
 					FW_INFO_OFFSET2, FW_INFO_OFFSET3,
-					FW_INFO_OFFSET4};
+					FW_INFO_OFFSET4, FW_INFO_OFFSET5,
+					FW_INFO_OFFSET6};
 
 
 /** Search for the firmware_info structure inside the firmware.

subsys/fw_info/Kconfig

@@ -18,10 +18,11 @@ config FW_INFO_API
 
 config FW_INFO_OFFSET
 	hex "The location of firmware info inside this firmware"
+	default 0x600 if SOC_SERIES_NRF54LX
 	default 0x200
 	help
 	  The location of firmware information inside the current firmware
-	  image. Valid values are 0x0, 0x200, 0x400, 0x800, and 0x1000.
+	  image. Valid values are 0x0, 0x200, 0x400, 0x600, 0x800, 0xe00, and 0x1000.
 	  Compatible readers of firmware information should search all possible
 	  offsets. Note that all space between the vector table and this address
 	  is unused.