This reverts commit a7e4f905d206d5895dab4bd38a8316e4f2fe15fe. The description originally written by Sughosh is still valid even after the commit 47a25e81d35c ("Revert "efi_capsule: Move signature from DTB to .rodata"") was applied.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- doc/develop/uefi/uefi.rst | 124 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+)
diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst index 4f2b8b036db8..f17138f5c765 100644 --- a/doc/develop/uefi/uefi.rst +++ b/doc/develop/uefi/uefi.rst @@ -277,6 +277,130 @@ Enable ``CONFIG_OPTEE``, ``CONFIG_CMD_OPTEE_RPMB`` and ``CONFIG_EFI_MM_COMM_TEE`
[1] https://optee.readthedocs.io/en/latest/building/efi_vars/stmm.html
+Enabling UEFI Capsule Update feature +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Support has been added for the UEFI capsule update feature which +enables updating the U-Boot image using the UEFI firmware management +protocol (FMP). The capsules are not passed to the firmware through +the UpdateCapsule runtime service. Instead, capsule-on-disk +functionality is used for fetching the capsule from the EFI System +Partition (ESP) by placing the capsule file under the +\EFI\UpdateCapsule directory. + +The directory \EFI\UpdateCapsule is checked for capsules only within the +EFI system partition on the device specified in the active boot option +determined by reference to BootNext variable or BootOrder variable processing. +The active Boot Variable is the variable with highest priority BootNext or +within BootOrder that refers to a device found to be present. Boot variables +in BootOrder but referring to devices not present are ignored when determining +active boot variable. +Before starting a capsule update make sure your capsules are installed in the +correct ESP partition or set BootNext. + +Performing the update +********************* + +Since U-boot doesn't currently support SetVariable at runtime there's a Kconfig +option (CONFIG_EFI_IGNORE_OSINDICATIONS) to disable the OsIndications variable +check. If that option is enabled just copy your capsule to \EFI\UpdateCapsule. + +If that option is disabled, you'll need to set the OsIndications variable with:: + + => setenv -e -nv -bs -rt -v OsIndications =0x04 + +Finally, the capsule update can be initiated either by rebooting the board, +which is the preferred method, or by issuing the following command:: + + => efidebug capsule disk-update + +**The efidebug command is should only be used during debugging/development.** + +Enabling Capsule Authentication +******************************* + +The UEFI specification defines a way of authenticating the capsule to +be updated by verifying the capsule signature. The capsule signature +is computed and prepended to the capsule payload at the time of +capsule generation. This signature is then verified by using the +public key stored as part of the X509 certificate. This certificate is +in the form of an efi signature list (esl) file, which is embedded as +part of U-Boot. + +The capsule authentication feature can be enabled through the +following config, in addition to the configs listed above for capsule +update:: + + CONFIG_EFI_CAPSULE_AUTHENTICATE=y + CONFIG_EFI_CAPSULE_KEY_PATH=<path to .esl cert> + +The public and private keys used for the signing process are generated +and used by the steps highlighted below:: + + 1. Install utility commands on your host + * OPENSSL + * efitools + + 2. Create signing keys and certificate files on your host + + $ openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=CRT/ \ + -keyout CRT.key -out CRT.crt -nodes -days 365 + $ cert-to-efi-sig-list CRT.crt CRT.esl + + $ openssl x509 -in CRT.crt -out CRT.cer -outform DER + $ openssl x509 -inform DER -in CRT.cer -outform PEM -out CRT.pub.pem + + $ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in CRT.crt + $ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem + +The capsule file can be generated by using the GenerateCapsule.py +script in EDKII:: + + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ + <capsule_file_name> --monotonic-count <val> --fw-version \ + <val> --lsv <val> --guid \ + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \ + --update-image-index <val> --signer-private-cert \ + /path/to/CRT.pem --trusted-public-cert \ + /path/to/CRT.pub.pem --other-public-cert /path/to/CRT.pub.pem \ + <u-boot.bin> + +Place the capsule generated in the above step on the EFI System +Partition under the EFI/UpdateCapsule directory + +Testing on QEMU +*************** + +Currently, support has been added on the QEMU ARM64 virt platform for +updating the U-Boot binary as a raw image when the platform is booted +in non-secure mode, i.e. with CONFIG_TFABOOT disabled. For this +configuration, the QEMU platform needs to be booted with +'secure=off'. The U-Boot binary placed on the first bank of the NOR +flash at offset 0x0. The U-Boot environment is placed on the second +NOR flash bank at offset 0x4000000. + +The capsule update feature is enabled with the following configuration +settings:: + + CONFIG_MTD=y + CONFIG_FLASH_CFI_MTD=y + CONFIG_CMD_MTDPARTS=y + CONFIG_CMD_DFU=y + CONFIG_DFU_MTD=y + CONFIG_PCI_INIT_R=y + CONFIG_EFI_CAPSULE_ON_DISK=y + CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y + CONFIG_EFI_CAPSULE_FIRMWARE=y + CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y + +In addition, the following config needs to be disabled(QEMU ARM specific):: + + CONFIG_TFABOOT + +The capsule file can be generated by using the tools/mkeficapsule:: + + $ mkeficapsule --raw <u-boot.bin> --index 1 <capsule_file_name> + Executing the boot manager ~~~~~~~~~~~~~~~~~~~~~~~~~~