wolfBoot for Renesas RZN2L with RSIP

1. Overview

This example demonstrates simple secure firmware boot from external flash by wolfBoot. The example uses SPI boot mode with external flash on the evaluation board. In addition to boot mode, this readme explains about RSIP driver use. RSIP provides Cryptographic accelerator, Random number generator and Secure key manegement.

A sample application v1 is securely loaded into internal RAM if there is not higher version in update region. A sample application v2 will be loaded when it is in update region.Both versions behave the same except blinking LED Red(v1) or Yellow(v2). They are compiled by e2Studio and running on the target board.

In this demo, you may download two versions of the application binary file. You can download and execute wolfBoot by e2Studio debugger. Use a USB connection between PC and the board for the debugger and flash programmer.

2. Components, Tools and Board Settings

2-1. Tools

Item	Name/Version	Note
Board	Renesas RZN2L RSK
Device	R9A07G084M08GBG
Toolchain	GCC ARM Embedded 10.3.1.20210824	Included in GCC for Renesas RZ
FSP Version	1.3.0	Download from Renesas site
IDE	e2studio 2024-01.1 (24.1.1)	Download from Renesas site
SEGGER J-Link	J-Link Commander V7.94j	Download from J-Link
Key tool	keygen and sign	Included in wolfBoot

FIT Components	Version	Note
Board Support Package Common Files	v1.3.0
I/O Port	v1.3.0
Arm CMSIS Version 5 - Core (M)	v5.7.0+renesas.1
Board support package for R9A07G084M04GBG	v1.3.0	Note1
Board support package for RZN2L	v1.3.0
Board support package for RZN2L - FSP Data	v1.3.0
RSK+RZN2L Board Support Files (xSPI0 x1 boot mode)	v1.3.0
SDRAM on Bus State Controller	v1.3.0
Renesas Secure IP Driver	v1.3.0+fsp.1.2.0
RSIP Engine for RZ/N2L	v1.3.0+fsp.1.2.0

Note1:
To use RSIP drive, a devvice type should be R9A07G084M04GBG. However, choosing R9A07G084M04GBG won't allow to select RSK+RZN2L board. This example uses LED and external flash memory on RSK + RZN2L board. Therefore, the example temporary R9A07G084M04GBG for the device type. Updating e2studio or fsp could resolve the issue.

2-2. Project folders

e2Studio Project:
wolfBoot IDE/Renesas/e2studio/RZN2L/wolfBoot
Sample app IDE/Renesas/e2studio/RZN2L/app_RZ
Flash Simple Loader IDE/Renesas/e2studio/RZN2L/flash_app

2-3. Board Settings

The switch and jumper settings required to run the sample program from external flash are shown below. For details on each setting, see the Renesas Starter Kit+ for RZN2L User's Manual.

Project	SW4-1	SW4-2	SW4-3	SW4-4	SW4-7
xSPI0 boot mode	ON	ON	ON	ON	OFF

Project	CN8	CN24
xSPI0 boot mode	Short 2-3	Short2-3

3. Operation Overview

The example uses SPI boot mode with external flash on the evaluation board. On this boot mode, the loader program, which is wolfBoot, is copied to the internal RAM(B-TCM). wolfBoot copies the encrypted RSIP key on flash memory and the application program from external flash memory to RAM(System RAM). As final step of wolfBoot the entry point of the copied application program is called if its integrity and authenticity are OK.

4. How to build and use

This section describes about how to build wolfBoot and application and use them.

4-1) Key generation

It has key tools running under the host environment such as Linux, Windows or MacOS. For compiling the tools, follow the instruction described in the user manual.

$ cd <wolfBoot>
$ make keytools RENESAS_KEY=3
$ export PATH=$PATH:<wolfBoot>/tools/keytools
$ keygen --rsa2048 -g ./pri-rsa2048.der  # RSA2048

The keygen tool generates a pair of private and public key with -g option. The private key is stored in the specified file. The public key is stored in a key store as a C source code in "src/keystore.c" so that it can be compiled and linked with wolfBoot. If you have an existing key pair, you can use -i option to import the public key to the store.

The example for Renesas RZ with RSIP only supports RSA 2048 bit now.

5) Compile wolfBoot

Open project under IDE/Renesas/e2studio/RZN2L/wolfBoot with e2Studio, and build the project.

5-1) Create `dummy_loader` application

Click File->New->RZ/N C/C++ FSP Project.
Select RSK+RZN2L (xSPI0 x1 boot mode) from Drop-down list.
Check Executable.
Select No RTOS from RTOS selection. Click Next.
Check Bare Metal Minimal. Click Finish.
Open Smart Configurator by clicking configuration.xml in the project
Go to BSP tab and increase LDR_SIZE_NML under RSK+RZN2L(xSIP0x1 boot mode) on Properties page, e.g. 0x00010000
Go to BSP tab and increase SVC Stack Size under RZN2L stack size on Properties page, e.g. 0x2000
Go to BSP tab and increase Heap Size under RZN2L on Properties page, e.g. 0x10000
Go to Stacks tab and add RSIP driver from New Stack -> Security
Select RSIP driver on Threads pain and open its property page
Disable algorithms except the following algorithms:
R_RSIP_KeyImportWithUFPK -> RSA-2048 PUblic Key (New format)
R_RSIP_RSAEncrypt/Verify -> RSA-2048 (for new-format wrapped key)
R_RSIP_RSADecrypt/Sign -> RSA-2048 (for new-format wrapped key)

This helps to reduce a loader footprint.

Save dummy_loader FSP configuration
Copy configuration.xml and pincfg under dummy_loader to wolfBoot
Open Smart Configurator by clicking copied configuration.xml
Click Generate Project Content on Smart Configurator
Righ click on the project and Open property of the project
Go to Cross ARM Linker
Change Script files(-T) from fsp_xspi0_boot.ld to fsp_xspi0_boot_loader.ld
Add/Modify FSP generated code :
fsp/src/bsp/cmsis/Device/RENESAS/Source/startup.c

ORIGINAL

BSP_TARGET_ARM BSP_ATTRIBUTE_STACKLESS void __Vectors (void)
{
    __asm volatile (
        "    ldr pc,=Reset_Handler            \n"

==>

MODIFIED

BSP_TARGET_ARM BSP_ATTRIBUTE_STACKLESS void __Vectors (void)
{
    /* This software loops are only needed when debugging. */
    __asm volatile (
        "    mov   r0, #0                         \n"
        "    movw  r1, #0xf07f                    \n"
        "    movt  r1, #0x2fa                     \n"
        "software_loop:                           \n"
        "    adds  r0, #1                         \n"
        "    cmp   r0, r1                         \n"
        "    bne   software_loop                  \n"
        ::: "memory");
    __asm volatile (
#if 0
        "    ldr pc,=Reset_Handler            \n"
#else
        "    ldr pc,=system_init              \n"
#endif

ORIGINAL

BSP_TARGET_ARM void mpu_cache_init (void)
{
...
#if BSP_CFG_C_RUNTIME_INIT  && !defined(EXTERNAL_LOADER)

    /* Copy the loader data from external Flash to internal RAM. */
    bsp_loader_data_init();

    /* Clear loader bss section in internal RAM. */
    bsp_loader_bss_init();
#endif
...
#if !(BSP_CFG_RAM_EXECUTION)

    /* Copy the application program from external Flash to internal RAM. */
    bsp_copy_to_ram();

    /* Clear bss section in internal RAM. */
    bsp_application_bss_init();
#endif
...
}

==>

MODIFIED

BSP_TARGET_ARM void mpu_cache_init (void)
{
...
if BSP_CFG_C_RUNTIME_INIT && !defined(EXTERNAL_LOADER)

    /* Copy the loader data from external Flash to internal RAM. */
    bsp_loader_data_init();

    /* Clear loader bss section in internal RAM. */
    bsp_loader_bss_init();
#endif
...
#if !(BSP_CFG_RAM_EXECUTION)

    /* Copy the application program from external Flash to internal RAM. */
    /* bsp_copy_to_ram(); */

    /* Clear bss section in internal RAM. */
    bsp_application_bss_init();
#endif
...
}

Build wolfBoot project

6) Compile the sample application

Open project under IDE/Renesas/e2studio/RZN2L/app_RZ with e2Studio, and build the project.

6-1). Create `dummy_application`

Click File->New->RZ/N C/C++ FSP Project.
Select RSK+RZN2L (xSPI0 x1 boot mode) from Drop-down list.
Check Executable.
Select No RTOS from RTOS selection. Click Next.
Check Bare Metal Minimal. Click Finish.
Open Smart Configurator by clicking configuration.xml in the project
Open Interrupts tab
Select INTCPU0 interrupts from New User Event -> ICU
Enter intcpu0_handler as interruption name
Save dummy_application FSP configuration
Copy configuration.xml and pincfg under dummy_application to app_RZ
Open Smart Configurator by clicking copied configuration.xml
Click Generate Project Content on Smart Configurator
Right click on the project and Open property of the project
Go to Cross ARM Linker
Change Script files(-T) from fsp_xspi0_boot.ld to fsp_xspi0_boot_app.ld
Add/Modify FSP generated code :
fsp/src/bsp/cmsis/Device/RENESAS/Source/startup.c

ORIGINAL

BSP_TARGET_ARM BSP_ATTRIBUTE_STACKLESS void __Vectors (void)
{
    __asm volatile (

==>

MODIFIED

BSP_TARGET_ARM BSP_ATTRIBUTE_STACKLESS void __Vectors (void)
{
    __asm volatile (
#if 0
        "    ldr pc,=Reset_Handler            \n"
#else
        "    ldr pc,=local_system_init        \n"
#endif

ORIGINAL

BSP_TARGET_ARM void mpu_cache_init (void)
{
...
#if BSP_CFG_C_RUNTIME_INIT

    /* Copy the loader data from external Flash to internal RAM. */
    bsp_loader_data_init();
...
#if !(BSP_CFG_RAM_EXECUTION)

    /* Copy the application program from external Flash to internal RAM. */
    bsp_copy_to_ram();
...
}

==>

MODIFIED

BSP_TARGET_ARM void mpu_cache_init (void)
{
...
if BSP_CFG_C_RUNTIME_INIT && !defined(EXTERNAL_LOADER_APP)

    /* Copy the loader data from external Flash to internal RAM. */
    bsp_loader_data_init();
....

#if !(BSP_CFG_RAM_EXECUTION) && !defined(EXTERNAL_LOADER_APP)

    /* Copy the application program from external Flash to internal RAM. */
    bsp_copy_to_ram();
...
}

Build app_RZ project

Code Origin and entry point is "0x10010000". app_RZ.bin is generated under Debug.

7) Generate a encryped Key for RSIP

RSIP needs to have a encrypted key for sign verification installed in advance. This section describes how to use wolfBoot with RSIP encrypted key. Current version supports RSA2048. RSIP RSA Signature supports #PKCS 1, v1.5. You can generate a RSA key pair by wolfBoot "keygen" command along with Renesas Security Key Management Tool, a.ka. skmt. The skmt tool's CUI interface generates a encrypted key from a RAW key and generates C language initial data and a header file for an application program with RSIP.

The example project assumes rsa_pub.h. Please specify rsa_pub.c for /output option. Similar to that, please specify rsa_public for /keyname option so that it can macth the example program expectation. After rsa_pub.h generated, you can copy the generated C header file to IDE/Renesas/e2studio/RZN2L/wolfboot/src.

$ export PATH:$PATH:<wolfBoot>/tools/keytools
$ export PATH:$PATH:<skmt>
$ cd <wolfBoot>
$ keygen --rsa2048 -g ./pri-rsa2048.der
$ openssl rsa -in pri-rsa2048.der -pubout -out pub-rsa2048.pem
$ skmt.exe /genkey /ufpk file=./ufpk_rzn2l.key /wufpk file=./ufpk_rzn2l.key_enc.key -key file=./pub-rsa2048.pem -mcu RZ-TSIP -keytype RSA-2048-public /output rsa_pub.c /filetype "csource" /keyname rsa_public
Output File: C:\workspace\wolfBoot_work\rsa_pub.h
Output File: C:\workspace\wolfBoot_work\rsa_pub.c
UFPK: F907AF3E87A8D9FED6FFCD246590EB5DCC9CA9AB1BF9160A8AA8CA4A4AEF2C19
W-UFPK: 00000000C0E4C5236974289C93F748C5C2C5310BDF1BE4753F4D8350D584F0674293F8F3
IV: 7AB13913EC6390A1AC1EB80FF0286CB6
Encrypted key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
$ cp rsa_pub.h IDE/Renesas/e2studio/RZN2L/wolfboot/src/rsa_pub.h

To write a encrypted key to flash, it generates a binary key by skmt.

$ skmt.exe /genkey /ufpk file=./ufpk_rzn2l.key /wufpk file=./ufpk_rzn2l.key_enc.key -key file=./pub-rsa2048.pem -mcu RZ-TSIP -keytype RSA-2048-public /output rsa_pub2048.bin /filetype "bin"
$ cp rsa_pub2048.bin IDE/Renesas/e2studio/RZN2L/flash_app

7) Generate Signature for app V1

The sign tool (tools/keytools/sign) generates a signature for the binary with a specified version. It generates a file contain a partition header and application image. The partition header contains the generated signature and other control fields. Output file name is made up from the input file name and version like app_RenesasRx01_v1.0_signed.bin.

# export PATH=$PATH:/path/to/wolfBoot-root/tools/keytools
$ cd IDE/Renesas/e2studio/RZN2L/app_RZ/Debug/
$ sign --rsa2048enc app_RZ.bin ../../../../../../pri-rsa2048.der 1.0
wolfBoot KeyTools (Compiled C version)
wolfBoot version 2000000
Update type:          Firmware
Input image:          app_RZ.bin
Selected cipher:      RSA2048
Selected hash  :      SHA256
Public key:           ../../../../../../pri-rsa2048.der
Output  image:        app_RZ_v1.0_signed.bin
Target partition id : 1
image header size calculated at runtime (512 bytes)
Calculating SHA256 digest...
Signing the digest...
Output image(s) successfully created.

Note2:
Please specify --rsa2048enc for sign tool option. Verify API of RSIP drive assumes to have DigestInfo for padding.

8) Download the app V1

To download the app V1 to external flash, you can use flash_simple_loader application which is located in /IDE/Renesas/e2studio/RZN2L/flash_app

Open project under IDE/Renesas/e2studio/RZN2L/flash_app with e2Studio, and build the project.

Copy configuration.xml and pincfg under dummy_application to flash_simple_loader
Open Smart Configurator by clicking configuration.xml in the project
Open Interrupts tab
Select INTCPU0 interrupts and remove it
Click Generate Project Content on Smart Configurator
Go to BSP tab and disable C Runtime Initialization under RZN2L on Properties page
Right click on the project and Open property of the project
Go to Cross ARM Linker
Change Script files(-T) from fsp_xspi0_boot.ld to fsp_xspi0_boot_loader.ld
Build flash_simple_loader project

To run the application,

Right-Click the Project name.
Select Debug As -> Renesas GDB Hardware Debugging
Select J-Link ARM. Click OK.
Select R9A07G084M04. Click OK.

This simple application just downloads binary files defined in Flash_section.s, Flash_update.s and Flash_wrappedkey_public.s through J-Link Flash Downloader. Flash_update.s doesn't include the app v2 initially and Flash_wrappedkey_public.s doesn't include key binary data. Please remove comment-out at Flash_wrappedkey_public.s, and then runs the program so that version 1 example and public key are downloaded to external flash memory.

Flash_wrappedkey_public.s

/* To download the encrypted rsip key, please remove comment out.  */
/* .incbin "../rsa_pub2048.bin" */

Flash_update.s

/* To download the app v2, please remove comment out.  */
/* .incbin "../../app_RZ/Debug/app_RZ_v2.0_signed.bin" */

9) Execute initial boot

Now, you can download and start wolfBoot program by e2Studio debugger. After starting the program, you can see the partition information as follows. If the boot program succeeds successfully and authenticity check then start application V1. To initially run wolfBoot project, 1.) Right-Click the Project name. 2.) Select Debug As -> Renesas GDB Hardware Debugging 3.) Select J-Link ARM. Click OK. 4.) Select R9A07G084M04. Click OK.

You can see RED LED blinking on the board.

10) Generate Signed app V2 and download it

Similar to V1, you can sign and generate a binary of V2. The update partition starts at "0x60180000".

$ sign --rsa2048enc app_RA.bin ../../../../../pri-rsa2048.der 2.0

To download the app V2, please remove comment out line in Flash_update.s of flash_simple_loader Flash_update.s

/* To download the app v2, please remove comment out.  */
.incbin "../../app_RZ/Debug/app_RZ_v2.0_signed.bin"

And then clean and build flash_simple_loader, run it

11) Re-boot and execute the app V2

The boot program compares version number of download images in external flash memory. It simply chooses hight version number from two images to run. The boot program downloads the selected image from flash to System Ram.

You can see now YELLOW LED blinking.

12) Erase flash memory

If you want to erase flash memory for initialization, you can use J-Link Commander tool.

Launch J-Link Commander tool.

SEGGER J-Link Commander V7.94j (Compiled Feb 14 2024 15:37:25)
DLL version V7.94j, compiled Feb 14 2024 15:36:06

Connecting to J-Link via USB...O.K.
Firmware: J-Link OB-S124 compiled Dec 13 2023 14:39:54
Hardware version: V1.00
J-Link uptime (since boot): 0d 01h 14m 48s
S/N: 831910878
USB speed mode: Full speed (12 MBit/s)
VTref=3.300V


Type "connect" to establish a target connection, '?' for help
J-Link>connect
Please specify device / core. <Default>: R9A07G084M04
Type '?' for selection dialog
Device>R9A07G084M08GBG
Please specify target interface:
  J) JTAG (Default)
  S) SWD
  T) cJTAG
TIF>S
Specify target interface speed [kHz]. <Default>: 4000 kHz
Speed>
Device "R9A07G084M08" selected.
...
J-Link>exec EnableEraseAllFlashBanks

e.g. erase all flash

erase 0x60100000,0x603FFFFF

e.g. erase BOOT PARTITION

erase 0x60100000,0x60180000

e.g. erase UPDATE PARTITION

erase 0x601800000,0x601E0000

13. References

For board settings:

RZN2L FSP Getting Started

Example Programs:

RZ/T2, RZ/N2 Group Device Setup Guide for Flash boot Sample program

RZ/N2L Group Example of separating loader program and application program projects

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wolfBoot for Renesas RZN2L with RSIP

1. Overview

2. Components, Tools and Board Settings

2-1. Tools

2-2. Project folders

2-3. Board Settings

3. Operation Overview

4. How to build and use

4-1) Key generation

5) Compile wolfBoot

5-1) Create `dummy_loader` application

6) Compile the sample application

6-1). Create `dummy_application`

7) Generate a encryped Key for RSIP

7) Generate Signature for app V1

8) Download the app V1

9) Execute initial boot

10) Generate Signed app V2 and download it

11) Re-boot and execute the app V2

12) Erase flash memory

13. References

FilesExpand file tree

Readme_wRSIP.md

Latest commit

History

Readme_wRSIP.md

File metadata and controls

wolfBoot for Renesas RZN2L with RSIP

1. Overview

2. Components, Tools and Board Settings

2-1. Tools

2-2. Project folders

2-3. Board Settings

3. Operation Overview

4. How to build and use

4-1) Key generation

5) Compile wolfBoot

5-1) Create dummy_loader application

6) Compile the sample application

6-1). Create dummy_application

7) Generate a encryped Key for RSIP

7) Generate Signature for app V1

8) Download the app V1

9) Execute initial boot

10) Generate Signed app V2 and download it

11) Re-boot and execute the app V2

12) Erase flash memory

13. References

5-1) Create `dummy_loader` application

6-1). Create `dummy_application`