wolfBoot/docs/Targets.md

Targets

STM32-F407

Example 512KB partitioning on STM32-F407

The example firmware provided in the test-app is configured to boot from the primary partition starting at address 0x20000. The flash layout is provided by the default example using the following configuration in target.h:

#define WOLFBOOT_SECTOR_SIZE              0x20000
#define WOLFBOOT_PARTITION_SIZE           0x20000

#define WOLFBOOT_PARTITION_BOOT_ADDRESS   0x20000
#define WOLFBOOT_PARTITION_UPDATE_ADDRESS 0x40000
#define WOLFBOOT_PARTITION_SWAP_ADDRESS   0x60000

This results in the following partition configuration:

This configuration demonstrates one of the possible layouts, with the slots aligned to the beginning of the physical sector on the flash.

The entry point for all the runnable firmware images on this target will be 0x20100, 256 Bytes after the beginning of the first flash partition. This is due to the presence of the firmware image header at the beginning of the partition, as explained more in details in Firmware image

In this particular case, due to the flash geometry, the swap space must be as big as 64KB, to account for proper sector swapping between the two images.

On other systems, the SWAP space can be as small as 512B, if multiple smaller flash blocks are used.

More information about the geometry of the flash and in-application programming (IAP) can be found in the manufacturer manual of each target device.

STM32L0x3

Example 192KB partitioning on STM32-L073

This device is capable of erasing single flash pages (256B each).

However, we choose to use a logic sector size of 4KB for the swaps, to limit the amount of writes to the swap partition.

The proposed geometry in this example target.h uses 32KB for wolfBoot, and two partitions of 64KB each, leaving room for up to 8KB to use for swap (4K are being used here).

#define WOLFBOOT_SECTOR_SIZE                 0x1000   /* 4 KB */
#define WOLFBOOT_PARTITION_BOOT_ADDRESS      0x8000
#define WOLFBOOT_PARTITION_SIZE              0x10000 /* 64 KB */
#define WOLFBOOT_PARTITION_UPDATE_ADDRESS    0x18000
#define WOLFBOOT_PARTITION_SWAP_ADDRESS      0x28000

Building

Use make TARGET=stm32l0. The option CORTEX_M0 is automatically selected for this target.

Known issues

With Ed25519 (default SIGN algorithm) it's not possible at the moment to compile wolfboot with optimizations, due to a GCC linker error complaining about a missing symbol __gnu_thumb1_case_uqi.

Possible workarounds:

• Compile ed25519 with debug (optimizations are disabled) : make TARGET=stm32l0 DEBUG=1
• Use ECDSA instead (which is much faster) : make TARGET=stm32l0 SIGN=ECC256

STM32G0x0/STM32G0x1

Example 128KB partitioning on STM32-G070:

• Sector size: 2KB
• Wolfboot partition size: 32KB
• Application partition size: 45 KB

#define WOLFBOOT_SECTOR_SIZE                 0x800   /* 2 KB */
#define WOLFBOOT_PARTITION_BOOT_ADDRESS      0x8000
#define WOLFBOOT_PARTITION_SIZE              0xB000 /* 45 KB */
#define WOLFBOOT_PARTITION_UPDATE_ADDRESS    0x13000
#define WOLFBOOT_PARTITION_SWAP_ADDRESS      0x1E000

Building

Use make TARGET=stm32l0. The option CORTEX_M0 is automatically selected for this target. The option NVM_FLASH_WRITEONCE=1 is mandatory on this target, since the IAP driver does not support multiple writes after each erase operation.

Compile with:

make TARGET=stm32g0 NVM_FLASH_WRITEONCE=1

Known issues

With Ed25519 (default SIGN algorithm) it's not possible at the moment to compile wolfboot with optimizations, due to a GCC linker error complaining about a missing symbol __gnu_thumb1_case_uqi.

Possible workarounds:

• Compile ed25519 with debug (optimizations are disabled) : make TARGET=stm32l0 DEBUG=1
• Use ECDSA instead (which is much faster) : make TARGET=stm32l0 SIGN=ECC256

SiFive HiFive1 RISC-V

Features

• E31 RISC-V 320MHz 32-bit processor
• Onboard 16KB scratchpad RAM
• External 4MB QSPI Flash

Default Linker Settings

• FLASH: Address 0x20000000, Len 0x6a120 (424 KB)
• RAM: Address 0x80000000, Len 0x4000 (16 KB)

Stock bootloader

Start Address: 0x20000000 is 64KB. Provides a "double tap" reset feature to halt boot and allow debugger to attach for reprogramming. Press reset button, when green light comes on press reset button again, then board will flash red.

Application Code

Start Address: 0x20010000

wolfBoot configuration

The default wolfBoot configuration will add a second stage bootloader, leaving the stock "double tap" bootloader as a fallback for recovery. Your production implementation should replace this and partition addresses in target.h will need updated, so they are 0x10000 less.

For testing wolfBoot here are the changes required:

1. Makefile arguments:

   • ARCH=RISCV
   • TARGET=hifive1

   make ARCH=RISCV TARGET=hifive1 RAM_CODE=1 clean
   make ARCH=RISCV TARGET=hifive1 RAM_CODE=1
   

   If using the riscv64-unknown-elf- cross compiler you can add CROSS_COMPILE=riscv64-unknown-elf- to your make or modify arch.mk as follows:

    ifeq ($(ARCH),RISCV)
   -  CROSS_COMPILE:=riscv32-unknown-elf-
   +  CROSS_COMPILE:=riscv64-unknown-elf-
   

2. include/target.h

Bootloader Size: 0x10000 (64KB) Application Size 0x40000 (256KB) Swap Sector Size: 0x1000 (4KB)

#define WOLFBOOT_SECTOR_SIZE                 0x1000
#define WOLFBOOT_PARTITION_BOOT_ADDRESS      0x20020000

#define WOLFBOOT_PARTITION_SIZE              0x40000
#define WOLFBOOT_PARTITION_UPDATE_ADDRESS    0x20060000
#define WOLFBOOT_PARTITION_SWAP_ADDRESS      0x200A0000

Build Options

• To use ECC instead of ED25519 use make argument SIGN=ECC256
• To output wolfboot as hex for loading with JLink use make argument wolfboot.hex

Loading

Loading with JLink:

JLinkExe -device FE310 -if JTAG -speed 4000 -jtagconf -1,-1 -autoconnect 1
loadbin factory.bin 0x20010000
rnh

Debugging

Debugging with JLink:

In one terminal: JLinkGDBServer -device FE310 -port 3333

In another terminal:

riscv64-unknown-elf-gdb wolfboot.elf -ex "set remotetimeout 240" -ex "target extended-remote localhost:3333"
add-symbol-file test-app/image.elf 0x20020100

riscv64-unknown-elf-objdump -D test-app/image.elf