Hi Harrison, On Tue, 30 Sept 2025 at 06:54, Harrison Mutai <[email protected]> wrote: > > On 29/09/2025 19:11, Tom Rini wrote: > > On Fri, Sep 26, 2025 at 05:09:53PM +0100, Harrison Mutai wrote: > >> Hi all, > >> > >> We recently applied changes to the transfer list library [1] to correct the > >> checksum calculation. Previously, we used a simple byte-sum approach. > >> However, we later realized this contradicts the Firmware Handoff > >> specification, which states: > >> > >>> The checksum is set to a value such that the XOR over every byte in the > >>> {tl_base_pa, …, tl_base_pa + used_size - 1} address range is equal to 0. > >> > >> This discrepancy creates problems when interoperating with Bloblist. > >> Should Bloblist’s checksum calculation be updated to follow the same > >> XOR-based method? > >> > >> [1] > >> https://review.trustedfirmware.org/c/shared/transfer-list-library/+/42548 > > > > Erm, since this has been out in the wild so to speak, we can't just > > change the algorithm without bumping some cardinal. Or are there yet > > other implementations that were doing what the spec said? > > > > Raymond; Thanks for setting up the handoff tests. The next release for > TF-A is planned for mid-November [1]. > > We’ve run into an issue where TF-A requires specific tags from the > transfer list library, but we can’t consume them due to the recent > checksum changes. > > Tom; As it stands, ours is the only implementation currently using the > updated checksum algorithm. There are two other consumers - OP-TEE and > EDK2. OP-TEE already has a patch in upstream review to move to the new > algorithm [2]. >
There is a question: How did you pass the OP-TEE CI test without U-Boot changes? There is a CI check QEMUv8_check2 in OP-TEE that builds with Firmware Handoff enabled, but the manifest is pointing to U-Boot v2025.07-rc1. So I think unless you have merged the updated checksum to U-Boot and updated the OP-TEE manifest with that commit-id, otherwise QEMUv8_check2 will still fail due to the mismatching checksum algorithm. Regards, Raymond > I’ve also reached out to the author of the EDK2 implementation to make > them aware of the change. > > [1] > https://trustedfirmware-a.readthedocs.io/en/latest/about/release-information.html > [2] https://github.com/OP-TEE/optee_os/pull/7531 >
