On Thu, Apr 17, 2025 at 12:15:42PM -0600, Simon Glass wrote: > This series adds a standard way of passing information between different > firmware phases. This already exists in U-Boot at a very basic level, in > the form of a bloblist containing an spl_handoff structure, but the intent > here is to define something useful across projects. > > The need for this is growing as firmware fragments into multiple binaries > each with its own purpose. Without any run-time connection, we must rely > on build-time settings which are brittle and painful to keep in sync. > > This feature is named 'standard passage' since the name is more unique > than many others that could be chosen, it is a passage in the sense that > information is flowing from one place to another and it is standard, > because that is what we want to create. > > The implementation is mostly a pointer to a bloblist in a register, with > an extra register to point to a devicetree, for more complex data. This > should cover all cases (small memory footprint as well as complex data > flow) and be easy enough to implement on all architectures. > > The emphasis is on enabling open communcation between binaries, not > enabling passage of secret, undocumented data, although this is possible > in a private environment. > > This series is available at u-boot-dm/pass-working
Before I get into further feedback, my first bit of feedback is that this breaks transfer list support. I didn't check this on Raymond's QEMU but did test it on vexpress_fvp_bloblist and expect QEMU is also broken. The most likely reason I think is: > passage: spl: Support passing the passage to U-Boot [snip] > xferlist: Drop old xferlist code These are not the same. And they should be. And they should be using the register layout / values other projects use today. And I am bluntly uninterested in who shuffled the registers around and made them no longer agree. What TF-A is doing now is what's in the wild now. And shame on them if there wasn't a good reason for changing things either. -- Tom
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