48 lines
2.0 KiB
Markdown
48 lines
2.0 KiB
Markdown
# Building and using MCUboot with RIOT
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MCUboot began its life as the bootloader for Mynewt. It has since
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acquired the ability to be used as a bootloader for RIOT as well.
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Currently the support is limited to the nrf52dk platform.
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## Building the bootloader itself
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In this first version, a prebuilt Mynewt binary is downloaded at
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compile time. This binary was compiled to do an integrity check, but
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not a signature check. In order to configure the bootloader for
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signature check it is necessary to re-compile it either with Mynewt
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or Zephyr, following the provided instructions.
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In the next version, it is planned to compile MCUboot using RIOT,
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which should be able to boot any of the supported OS images.
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## Building applications for the bootloader
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A compatible MCUboot image can be compiled by typing: `make mcuboot`.
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The only variable which needs to be set is `IMAGE_VERSION` loaded
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with a valid formatted value. The format is `major.minor.patch+other`
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(e.g. `export IMAGE_VERSION= 1.1.1+1`. This variable can be either
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exported in the Makefile or manually, prior to the compilation process.
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The goal is to produce an ELF file which is linked to be flashed at a
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`BOOTLOADER_OFFSET` offset rather than the beginning of ROM. MCUboot
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also expects an image padded with some specific headers containing the
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version information, and trailer type-length-value records (TLVs) with
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hash and signing information. This is done through the imgtool.py
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application, which is executed automatically by the RIOT build system.
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### Signing the application
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The application will be automatically signed with the provided key.
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If no key is provided, a new key will be automatically generated. The
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default key type is RSA-2048.
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In order to use your provided key, you need to recompile the bootloader
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using you public key, either in Zephyr or Mynewt by following the
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provided procedure for the selected OS.
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### Flashing the application
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The application can be flashed by typing: `make flash-mcuboot`.
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This will flash both the bootloader and the application.
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