Image Layout

The purpose of this document is to provide an introduction to image layout, covering the following two aspects:

  • Flash Layout

    • Overview of the image layout in Flash, aiming to prevent misuse.

    • Steps on how to adjust the Flash Layout.

  • Image Data Layout

    • Introduce parts in images.

Flash Layout

In order to use the flash more conveniently and prevent misuse, Flash Layout is introduced.

RTL87x3E Flash Layout

Images can be divided into two categories: High Level Images and BANK Images.

RTL87x3E Flash Layout indicates the start address and max size of images in flash:

  1. The configurations of the system config image(OEM HEADER) and BOOT PATCH are fixed in the ROM and can’t be changed.

  2. The configurations of PLATFORM_EXT, LOWERSTACK_EXT and UPPERSTACK are recorded in BOOT PATCH and can’t be changed.

  3. The OEM HEADER records the layout of high level images.

  4. The OTA Header, fixed at the beginning of the BANKx area, defines the layout of images in the same BANKx.

High Level Images

The high level images of Flash Layout are shown in the following figure.

Note

  1. The BKP DATAx sections are reserved.

  2. After the flash map is modified, please make sure to regenerate the related images.

  3. The Flash Layout of all images should not overlap, and the Flash Layout of the high level images should not overlap either. The Flash Layout size of the image should be larger than the image size. It is also suggested to be aligned by flash sector size (0x1000 bytes). If two images share one flash sector, they should download together, as the minimum flash erase size is the flash sector size.

Let’s take the 4M flash map as an example to show the description of the Flash Layout in the following map. Similarly, the other Flash Layouts can be described according to their corresponding flash_map.h.

Memory Segment

Starting Address

Size (Bytes)

Functions

RSVD

0x02000000

0x00002000

Reserved.

OEM HEADER

0x02002000

0x00002000

Stores configuration information, which includes Bluetooth Address and user defined Flash Layout.

BOOT PATCH

0x02004000

0x00002000

Flash boot loader.

PLATFORM_EXT

0x02006000

0x00008000

Stores Platform extension information.

LOWERSTACK_EXT

0x0200E000

0x00007000

Stores Bluetooth Controller extension information.

UPPERSTACK

0x02015000

0x0003F000

Stores Bluetooth Host information.

BANK0

0x02054000

0x001AC000

Stores data and code running area, further subdivided into OTA Header, FSBL, Stack Patch, SYS Patch, APP, DSP SYS, DSP APP, DSP CFG, APP CFG, and EXT images.

BANK1

0x02200000

0x001AC000

The same as BANK0, and the size of BANK1 must also be the same as BANK0.

VP_DATA

0x023AC000

0x00032000

Stores VP data.

FTL

0x023DE000

0x00015000

Supports accessing flash with a logical address. Users can read/write flash with a unit size of at least 4 bytes.

BKP DATA1

0x00000000

0x00000000

Optional to use. Stores any data.

BKP DATA2

0x023FE000

0x00002000

Optional to use. Stores any data.

OTA_TMP_ADDR

0x00000000

0x00000000

Optional to use. For OTA.

BANK Images

For RTL87x3E, BANK0 can be subdivided into the following images:

Memory Segment

Starting Address

Size (Bytes)

Functions

OTA Header

0x02054000

0x00000400

OTA version, start address, and size of each BANK.

FSBL

0x02054400

0x00001C00

Flash secure boot loader.

Stack Patch

0x02056000

0x0003D000

Stack optimization and extension code.

SYS Patch

0x02093000

0x0001D000

Optimized and expanded code for systems in non-secure ROM.

APP

0x020B0000

0x000DE000

Running code for development solutions.

DSP SYS

0x0218E000

0x00020000

DSP system information.

DSP APP

0x021AE000

0x00038000

DSP running code.

DSP CFG Data

0x021E6000

0x0000A000

DSP config information.

APP CFG Data

0x021F0000

0x00002000

APP config information.

EXT_IMG0

0x021F2000

0x0000A000

Optional to use. Stores any data.

EXT_IMG1

0x021FC000

0x00004000

Optional to use. Stores any data.

EXT_IMG2

0x00000000

0x00000000

Optional to use. Stores any data.

EXT_IMG3

0x00000000

0x00000000

Optional to use. Stores any data.

RTL87x3EP Flash Layout

Images can be divided into two categories: High Level Images and BANK Images. RTL87x3EP Flash Layout indicates the start address and max size of images in flash:

  1. The configurations of the OEM HEADER and BOOT PATCH are fixed in the ROM and can’t be changed.

  2. The configurations of PLATFORM_EXT, LOWERSTACK_EXT, and UPPERSTACK are recorded in BOOT PATCH and can’t be changed.

  3. The OEM HEADER records the layout of high level images.

  4. The OTA Header, fixed at the beginning of the BANKx area, defines the layout of images in the same BANKx.

High Level Images

The high level images of the Flash Layout are shown in the following figure.

Note

  1. The BKP DATAx sections are reserved.

  2. The BOOT PATCH0 and the BOOT PATCH1 should exist at the same time. They could record the PLATFORM_EXT, LOWERSTACK_EXT, and UPPERSTACK info.

  3. After the flash map is modified, please make sure to regenerate the related images.

  4. The Flash Layout of all images should not overlap, and the Flash Layout of the high level images should not overlap either. The Flash Layout size of the image should be larger than the image size. It is also suggested to be aligned by flash sector size (0x1000 bytes). If two images share one flash sector, they should download together, as the minimum flash erase size is the flash sector size.

Let’s take the 4M flash map as an example to show the detailed description of the Flash Layout in the following figure. Similarly, the other Flash Layouts can be described according to their corresponding flash_map.h.

Memory Segment

Starting Address

Size (Bytes)

Functions

RSVD

0x02000000

0x00002000

Reserved.

OEM HEADER

0x02002000

0x00002000

Stores configuration information which includes Bluetooth Address and user defined Flash Layout.

BOOT PATCH0

0x02004000

0x00003000

Flash boot loader.

BOOT PATCH1

0x02007000

0x00003000

Flash boot loader.

PLATFORM_EXT

0x0200A000

0x00008000

Stores Platform extension information.

LOWERSTACK_EXT

0x02012000

0x0000D000

Stores Bluetooth Controller extension information.

UPPERSTACK

0x0201F000

0x0003F000

Stores Bluetooth Host information.

BANK0

0x0205E000

0x001AC000

Stores data and code running area, further subdivided into OTA Header, FSBL, Stack Patch, SYS Patch, APP, DSP SYS, DSP APP, DSP CFG, APP CFG, and EXT images.

BANK1

0x0220A000

0x001AC000

The same as BANK0, and the size of BANK1 must also be the same as BANK0.

VP_DATA

0x023B6000

0x00032000

Stores VP data.

FTL

0x023E8000

0x00008000

Support accessing flash with logic address. User can read/write flash with unit size of 4 bytes at least.

BKP DATA1

0x00000000

0x00000000

Optional to use. Stores any data.

BKP DATA2

0x00000000

0x00000000

Optional to use. Stores any data.

OTA_TMP_ADDR

0x00000000

0x00000000

Optional to use. For OTA.

BANK Images

For RTL87x3EP, BANK0 could be subdivided into the following images:

Memory Segment

Starting Address

Size (Bytes)

Functions

OTA Header

0x02054000

0x00000400

OTA version, start address, and size of each BANK.

Stack Patch

0x02056000

0x0003D000

Stack optimization and extension code.

SYS Patch

0x02093000

0x0001D000

Optimized and expanded code for systems in non-secure ROM.

APP

0x020B0000

0x000DE000

Running code for development solutions.

DSP SYS

0x0218E000

0x00020000

DSP system information.

DSP APP

0x021AE000

0x00038000

DSP running code.

DSP CFG Data

0x021E6000

0x0000A000

DSP config information.

APP CFG Data

0x021F0000

0x00002000

APP config information.

EXT_IMG0

0x021F2000

0x0000A000

Optional to use. Stores any data.

EXT_IMG1

0x021FC000

0x00004000

Optional to use. Stores any data.

EXT_IMG2

0x00000000

0x00000000

Optional to use. Stores any data.

EXT_IMG3

0x00000000

0x00000000

Optional to use. Stores any data.

RTL87x3D Flash Layout

Images can be divided into two categories: High Level Images and BANK Images.

RTL87x3D Flash Layout indicates the start address and max size of images in flash:

  1. The configurations of the OEM HEADER and BOOT PATCH are fixed in ROM, which can’t be changed.

  2. The OEM HEADER includes the layout of high level images (except images in BANKx). See High Level Images.

  3. The OTA Header fixed at the beginning of the BANKx area defines the layout of images in the same BANKx.

High Level Images

The high level images of Flash Layout is shown in the following figure.

Note

  1. The BKP_DATA sections are reserved.

  2. After the flash map is modified, please make sure to regenerate the related images.

  3. The Flash Layout of all images should not overlap, and the Flash Layout of the high level images should not overlap either. The Flash Layout size of the image should be larger than the image size. It is also suggested to be aligned by flash sector size (0x1000 bytes). If two images share one flash sector, they should download together, as the minimum flash erase size is flash sector size.

Let’s take the 16M flash map as an example to show the detailed description of the Flash Layout in the following figure. Similarly, the other Flash Layout can be described according to its corresponding flash_map.h.

Memory Segment

Starting Address

Size (Bytes)

Functions

RSVD

0x02000000

0x00002000

Reserved.

OEM HEADER

0x02002000

0x00002000

Stores configuration information which includes Bluetooth Address and user-defined Flash Layout.

BOOT PATCH

0x02004000

0x00002000

Flash boot loader.

BANK0

0x02006000

0x00600000

Stores data and code running area, further subdivided into OTA Header, FSBL, Stack Patch, SYS Patch, APP, DSP SYS, DSP APP, DSP CFG, APP CFG, and EXT images.

BANK1

0x02606000

0x00600000

The same as BANK0, and the size of BANK1 must also be the same as BANK0.

FTL

0x02C06000

0x0000F000

Support accessing flash with logic address. User can read/write flash with unit size of 4 bytes at least.

BKP DATA1

0x00000000

0x00000000

Optional to use. Stores any data.

BKP DATA2

0x00000000

0x00000000

Optional to use. Stores any data.

OTA_TMP_ADDR

0x00000000

0x00000000

Optional to use. For OTA.

BANK Images

For RTL87x3D, BANK0 could be subdivided into the following images:

Memory Segment

Starting Address

Size (Bytes)

Functions

OTA Header

0x02606000

0x00001000

OTA version, start address, and size of each BANK.

FSBL

0x02607000

0x00003000

Flash secure boot loader.

ROM Patch

0x0260A000

0x00018000

Optimized and expanded code for systems in non-secure ROM.

Stack Patch

0x02622000

0x00040000

Stack optimization and extension code.

APP

0x02662000

0x00160000

Running code for development solutions.

DSP SYS

0x027C2000

0x000B0000

DSP system information.

DSP APP

0x02872000

0x00060000

DSP running code.

DSP CFG Data

0x028D2000

0x00005000

DSP Config information.

APP CFG Data

0x028D7000

0x0001A000

APP Config information.

EXT_IMG0

0x028F1000

0x0000A000

Optional to use. Stores any data.

EXT_IMG1

0x028FB000

0x002F2000

Optional to use. Stores any data.

EXT_IMG2

0x00000000

0x00000000

Optional to use. Stores any data.

EXT_IMG3

0x02BED000

0x00019000

Optional to use. Stores any data.

How to Configure Flash Layout

Flash Map Generator in the MPPG Tool is designed to generate flash_map.ini and flash_map.h, which determine the Flash Layout. The flash_map.ini will be used by MPPG Tool and MCUConfig Tool.

  1. To generate the flash_map.ini by ‘Flash Map Generator’, open the MPPG Tool first.

  2. Configure the whole Flash Layout in the ‘High Level Type’ list and configure the layout for BANKx in the ‘OTA File Type’ list after selecting ‘Flash Size’ combo box. Multi-image Header size is provided in the ‘Image Header Size’ combo box. ‘Set BP Size to Front’ combo box determines which area of the flash the BP level protects. Notice that items which ‘write enable’ is selected ‘RW’ should be placed out of BP size. Import an existing flash_map.ini by clicking the ‘Import’ button and then modify the layout based on it. Lastly, click the ‘Generate’ button to generate a new flash_map.ini.

    For RTL87x3E, the Flash Map Generator is as follows:

    For RTL87x3EP, the Flash Map Generator is as follows:

    For RTL87x3D, the Flash Map Generator is as follows:

    Note

    Please refer to the MPPG Tool Chain User Guide in the tool\MPPGTool directory for details.

Bring New Flash Layout into Effect

Users can adjust the Flash Layout in the flash_map.ini and flash_map.h through the ‘Flash Map Generator’ in the MPPG Tool under the ‘Tool’ menu. But there are some constraints for the Flash Layout adjustment.

  • The image address and size are suggested to be aligned by 0x1000 bytes for the minimum size for flash erase is flash sector size. If there are two images in one flash sector, these two images should be updated together.

  • Not all images’ layout can be adjusted.

Constraints and Restrictions Brief

Flash Layout for images can be adjusted under some constraints and restrictions according to the image types. Images can be categorized into the following types:

  • Images of fixed address

    • RTL87x3E: BOOT PATCH image, LOWERSTACK_EXT image, PLATFORM_EXT image, UPPERSTACK image.

    • RTL87x3EP: BOOT PATCH image, LOWERSTACK_EXT image, PLATFORM_EXT image, UPPERSTACK image.

    • RTL87x3D: BOOT PATCH image.
      The flash address for these images can’t be changed.

  • Patch code images

    • RTL87x3E: FSBL image, SYS Patch image, Stack Patch image.

    • RTL87x3EP: SYS Patch image, Stack Patch image.

    • RTL87x3D: FSBL image, ROM Patch image, Stack Patch image.
      When these images are released with position independent attribute, changing the Flash Layout for these images just needs to update the content of these images through the tool update_images_by_flash_map.exe under the directory of sdk\tool\Gadgets\update_images_by_flash_map.

  • APP code image
    APP image is compiled related with the APP flash address in the Flash Layout, and it should be recompiled with the new Flash Layout. The FTL is not an image, and if the FTL address or size is changed, APP image should be recompiled with the new flash map, please refer to FTL POOL.

  • OEM HEADER image
    The high level Flash Layout configurations are placed in the OEM HEADER. Therefore, if the high level Flash Layout are changed, the OEM HEADER should be updated. If the system config image can’t be updated through the OTA upgrade procedure, all the high level Flash Layouts can’t be modified again.

  • OTA Header image
    All the Flash Layout information for the images in the BANK are placed in the OTA Header image for each BANK. If the Flash Layout for the BANK images is changed, the OTA Header image should be updated. If the address of the OTA Header image in BANKx is changed, please keep the address of OTA BANK0 or OTA BANK1 in the high level the same with it.

  • VP data image for RTL87x3E
    The Flash Layout information for VP data image on the RTL87x3E is related to storage partition in the APP code image. If the Flash Layout for VP data image is changed, the APP code image must be recompiled.

  • Other images

    • RTL87x3E: DSP SYS image, DSP APP image, DSP data image, APP config data image, ext image0~3.

    • RTL87x3EP: DSP SYS image, DSP APP image, DSP data image, APP config data image, ext image0~3.

    • RTL87x3D: DSP SYS image, DSP APP image, DSP data image, APP config data image, ext image0~3.
      The Flash Layout for these images can be adjusted without updating the content of these images.

Users should update images according to the actual Flash Layout adjustment situation:

  1. If the high level Flash Layout configuration about OTA BANK0, OTA BANK1, BKP DATAx and OTA_TMP_ADDR are not changed, and also the Flash Layout for FSBL/SYS Patch/ROM Patch/Stack Patch are not changed, only the Flash Layout for APP image, DSP related images, APP config image or ext image0~3 are changed, users need to recompile the APP image with new Flash Layout, please refer to Recompile APP Image, and update the OTA Header image, please refer to Update OTA Header Image.

  2. If the high level Flash Layout configuration about OTA BANK0, OTA BANK1, BKP DATAx and OTA_TMP_ADDR are changed, users need to update the system config image through MCUConfig Tool, please refer to Update System Config Image.

  3. If the Flash Layout for FSBL, SYS Patch, ROM Patch and Stack Patch are not changed, but the Flash Layout for APP image, DSP related images, APP config image or ext image0~3 is changed, users need to recompile the APP image with new Flash Layout, please refer to Recompile APP Image, and update the OTA Header image, please refer to Update OTA Header Image.

  4. If the Flash Layout for FSBL, SYS Patch, ROM Patch and Stack Patch are changed, users can update the content of these images by update_images_by_flash_map.exe without recompiling, please refer to Update Image Content by Flash Map.

So the OTA Header image should be updated by referring to Update OTA Header Image when the image layout in the BANK is changed, and the OEM HEADER image should be updated by referring to Update System Config Image when the high layer Flash Layout is changed, and the Flash Layout for FSBL/SYS Patch/ROM Patch/Stack Patch can be changed by updating the content with the update_images_by_flash_map.exe by referring to Update Image Content by Flash Map. And APP image needs to be recompiled with new flash map by referring to Recompile APP Image if the Flash Layout for APP image is changed.

Update System Config Image

If the high level Flash Layout configuration about OTA BANK0, OTA BANK1, BKP DATAx, and OTA_TMP_ADDR is changed, the system config image should be updated through MCUConfig Tool.

Open MCUConfig Tool and switch to the ‘System Configuration’ tab, scroll down to the ‘OEM Header Setting’ group, then click the ‘Import flash_map.ini’ button to load the new flash map. A new system config image will be generated.

Update OTA Header Image

If the image layout in the BANK is changed, the OTA Header image should be updated through MPPG Tool.

Open MPPG Tool:

  • Click the menu Tool -> Generate OTA Header.

  • Click the ‘Load Flash Layout’ button to load the new flash map.ini.

  • Select OTA BANK ‘Bank0’ or ‘Bank1’.

  • Set the OTA image version. The OTA image version is used for BANK switch.

  • Set the RSA key through the ‘Load RSA Key’ button.

  • Click the ‘Generate’ button to generate the OTA Header with the new Flash Layout.

Update Image Content by Flash Map

All FSBL/SYS Patch/ROM Patch/Stack Patch images are compiled with position independent attribute in the SDK package. With this user guide, the image content can be updated by the tool update_images_by_flash_map.exe with the new flash map without recompiling.

It’s suggested to copy related files into a new work directory:

  • Collect the images (FSBL/SYS Patch/Stack Patch/ROM Patch) adjusted by Flash Layout adjusted according to BANK. If there’s only one BANK, take the BANK type as BANK0.

  • Copy update_images_by_flash_map.exe under the sdk\tool\Gadgets\update_images_by_flash_map to the new work directory.

  • If the images need to be signed by the RSA private key on the secure device, copy the RSA private key to the new work directory. The RSA signature can be updated by the tool update_images_by_flash_map.exe. Of course, all images can be updated with the RSA signature by the resign tool under sdk\tool\Gadgets\resign_tool.

Run the command to update the images by BANK, specify the BANK type by ‘–bank_type 0’ or ‘–bank_type 1’, specify the out directory through ‘-o out_directory_path’ and specify the new flash_map.ini by ‘–flash_map_ini’. Use ‘-d update_images_path’ to update the images under the directory of update_images_path, and use ‘-f update_image_path’ to update the specified image file.

Take BANK0 images as an example, update image content for BANK0 with new flash_map.ini by the following command line:

  • Update images in BANK0 under the directory.

    update_images_by_flash_map.exe --flash_map_ini NEW_FLASH_MAP_INI_PATH -d UPDATE_IMG_DIR_FOR_BANK0 --bank_type 0 -o OUT_DIRECTORY

  • Update the specified single image in BANK0.

    update_images_by_flash_map.exe --flash_map_ini NEW_FLASH_MAP_INI_PATH -f UPDATE_IMG_FILE_PATH --bank_type 0 -o OUT_DIRECTORY

For BANK1 images, use ‘–bank_type 1’ in the command line:

  • Update images in BANK1 under the directory. 

    update_images_by_flash_map.exe --flash_map_ini NEW_FLASH_MAP_INI_PATH -d UPDATE_IMG_DIR_FOR_BANK1 --bank_type 1 -o OUT_DIRECTORY

  • Update the specified single image in BANK1. 

    update_images_by_flash_map.exe --flash_map_ini NEW_FLASH_MAP_INI_PATH -f UPDATE_IMG_FILE_PATH --bank_type 1 -o OUT_DIRECTORY

Recompile APP Image

If the image layout for the APP is changed, the APP image should be recompiled:

  • Copy the new flash_map.h and flash_map.ini to sdk\bin\flash_map_config to replace the old ones.

  • Recompile the APP project to generate an APP image with the new Flash Layout.

Download Images with New Flash Layout

The Flash Layout modification would take effect after downloading the images into flash using MPPG Tool with new flash_map.ini. Please pay attention to the flash_map.ini setting and BANK type setting on the UI. For a secure device, please pay attention to the image resign operation.

Generate Ext Image Command Line

The prepend_header.exe and md5.exe under sdk\tool\Gadgets will be used.

  1. Use prepend_header.exe to add the Image Header for ext Image Payload.
    The output file name is the same as the input file name.

    ext_image0:

    prepend_header.exe /ext_image0 ext_image0.bin /ic_type IC_TYPE

    ext_image1:

    prepend_header.exe /ext_image1 ext_image1.bin /ic_type IC_TYPE

    ext_image2:

    prepend_header.exe /ext_image2 ext_image2.bin /ic_type IC_TYPE

    ext_image3:

    prepend_header.exe /ext_image3 ext_image3.bin /ic_type IC_TYPE

    For RTL87x3E, use ‘/ic_type 87x3E’. For RTL87x3EP, use ‘/ic_type 8773E’. For RTL87x3D, use ‘/ic_type 87x3D’.

  2. Add MP Header for ext image through mp.ini.
    The output file name will append _MP after the input file name.

    ; This is a config file mp.ini used by prepend_header tool to generate MP Header for a given image.
; 
; The following sections are mandatory: BinID, Version, PartNumber.
; 
; Note that MP Header is a 512-byte fixed data area, pay attention to the long strings that have
; been written and ensure they are not out of bounds of the Header.


[MandatoryInfo]

; Image type of current binary file.
BinID=ID_EXT_IMAGE1

; Version of current binary file. Range: 0.0.0.0 ~ 255.255.255.255
Version=1.0.0.0

; Part number of current image, ASCII type, 32 bytes maximum.
PartNumber=RTL87x3E


[OptionalInfo]

; Optional. Fill the required version number in specific field if specific image is needed. 
; Item will be ignored if the format of the value is wrong or the value does not exist.
DependOnSocvConfig      =
DependOnOemConfig       =
DependOnFactoryMp       =
DependOnFsbl            =
DependOnOtaHeader       =
DependOnPatch           =
DependOnApp             =
DependOnAppData         =
DependOnAppDataTone     =
DependOnAppDataVp       =
DependOnAppDspParam     =
DependOnDspSys          =
DependOnDspPatch        =
DependOnDspScenario1    =
DependOnDspScenario2    =

; Optional ASCII type comment string, 255 bytes maximum.
Comment=

; Optional ASCII type author information string, 255 bytes maximum.
Author=

; Optional ASCII type date and time string, 255 bytes maximum.
Date=

; Optional bin Header format revision.
Revision=0x01

    BinID for ext image in the mp.ini is defined as follows, please set the BinID according to the image type.

    Ext Image Type

    BinID in mp.ini

    ext_image0

    ID_EXT_IMAGE0

    ext_image1

    ID_EXT_IMAGE1

    ext_image2

    ID_EXT_IMAGE2

    ext_image3

    ID_EXT_IMAGE3

    Add MP Header command lines:

    ext_image0:

    prepend_header.exe /ext_image0 ext_image0.bin /mp_ini mp_ext_img0.ini  /ic_type IC_TYPE

    ext_image1:

    prepend_header.exe /ext_image1 ext_image1.bin /mp_ini mp_ext_img1.ini  /ic_type IC_TYPE

    ext_image2:

    prepend_header.exe /ext_image2 ext_image2.bin /mp_ini mp_ext_img2.ini  /ic_type IC_TYPE

    ext_image3:

    prepend_header.exe /ext_image3 ext_image3.bin /mp_ini mp_ext_img3.ini  /ic_type IC_TYPE

  3. Add MD5 data in the image file name for ‘ext_imageN_MP.bin’.
    The output file name will be ‘ext_imageN_MP-MD5Number.bin’.

    md5.exe ext_imageN_MP.bin

Image Data Layout

Each image includes three parts: MP Header, Image Header, and Image Payload. The three parts will be introduced separately later.

Some config data images may exist extended data after the Image Payload, and the extended data length is not included in the image length of MP Header and the Image Payload length of Image Header.

MP Header Layout

The size of MP Header is 512 Bytes on all ICs. The information in the MP Header is used by the tools (MPPG Tool and OTA Tool) for performing checks, and it will be stripped by the tools before being downloaded to the MCU. The data format is as follows (taking image size as an example):

Type ID

Data Length

Data

0x0014

0x04

Image Size

Image Header Layout

The Image Header includes information about the image, such as length and secure information. The format of the Image Header for all images on the specified IC is the same. However, some items are useful only in certain images, while they are reserved in others. The default Image Header size varies for different ICs.

RTL87x3E and RTL87x3EP

The default length of the Image Header for RTL87x3E and RTL87x3EP is 1024 bytes. The information in the Image Header Layout is shown in the following map.

Memory Segment

Size (Bytes)

Functions

Image_cmac

16

CMAC of the Image, for authentication if secure boot is enabled. NOTE that this field should be all 0xFF when downloading the image file to flash, and it can be recalculated.

Image_signature

256

Signature of the image, for authentication if secure boot is enabled.

Image_hash

32

SHA256 of the image, used to check integrity.

Image Control Header

12

Includes essential information for this image, see Image Control Header Items intro for details.

UUID

16

Should be consistent with ROM UUID.

Exe Base

4

Image entry address.

Load Base

4

Start address of code which should be loaded to RAM.

Load Len

4

Code length of code which should be loaded to RAM.

Image Base

4

Flash Layout of this image.

Device ID

2

NOT used.

Flash Layout Size

2

Used when flash size is larger than layout size.

Decode Key

16

NOT used.

Load Destination Address

4

Specifies the RAM address to copy the image from flash to RAM.

Ex_info

24

Used to configure heap range. Only used in APP image.

Git/Svn Version

16

For image version control if Git or SVN is used. Optional.

RSA Public Key

260

For image authentication if secure boot is enabled.

Ver_val

4

OTA Header image version. Only used in OTA Header image.

Image Info

128

Used to define layout of images in BANKx. Only used in OTA Header image and BOOT PATCH image. See Image Info Items.

RSVD

216

Reserved for future use. Same as OTA BANK Sub-image Header.

RTL87x3D

The default length of the Image Header for RTL87x3D is 4096 bytes. The information in the Image Header Layout is shown in the following map.

Memory Segment

Size (Bytes)

Functions

Image_cmac

16

CMAC of the Image, for authentication if secure boot is enabled. NOTE that this field should be all 0xFF when downloading the image file to flash, and it can be recalculated.

Image_signature

256

Signature of the image, for authentication if secure boot is enabled.

Image_hash

32

SHA256 of the image, used to check integrity.

Image Control Header

12

Includes essential information for this image, see Image Control Header Items intro for details.

UUID

16

Should be consistent with ROM UUID.

Exe Base

4

Image entry address.

Load Base

4

Start address of code which should be loaded to RAM.

Load Len

4

Code length of code which should be loaded to RAM.

Image Base

4

Flash Layout of this image.

Device ID

2

NOT used.

Flash Layout Size

2

Used when flash size is larger than layout size.

Decode Key

16

NOT used.

Load Destination Address

4

Specifies the RAM address to copy the image from flash to RAM.

Ex_info

24

Used to configure heap range. Only used in APP image.

Git/Svn Version

16

For image version control if Git or SVN is used. Optional.

RSA Public Key

260

For image authentication if secure boot is enabled.

Ver_val

4

OTA Header image version. Only used in OTA Header image.

Image Info

128

Used to define layout of images in BANKx. Only used in OTA Header image and BOOT PATCH image. See Image Info Items.

RSVD

216

Reserved for future use. Same as OTA BANK Sub-image Header.

Dummy Data

3072

Reserved for dummy data.

Image Control Header Items

The Image Control Header includes basic information about this image. It’s in the Image Header. The format is shown in the following figure.

Note

For SocV/OEM Header Image, two fields of ICH are required and should be filled with the correct data: Image ID and Payload Length.

Image Info Items

The image_info in the Image Header of the OTA Header and BOOT PATCH defines the Flash Layout of some images. The format of image_info is different on different ICs.

RTL87x3E

The image_info in RTL87x3E is as follows.

RTL87x3EP

The image_info in RTL87x3EP is as follows.

RTL87x3D

The image_info in RTL87x3D is as follows.