On 10.11.21 08:20, Jan Kiszka wrote: > On 10.11.21 07:55, Jan Kiszka wrote: >> On 10.11.21 01:58, Simon Glass wrote: >>> Hi, >>> >>> On Tue, 9 Nov 2021 at 02:17, Jan Kiszka <[email protected]> wrote: >>>> >>>> On 08.11.21 16:28, Roman Kopytin wrote: >>>>> In order to reduce the coupling between building the kernel and >>>>> U-Boot, I'd like a tool that can add a public key to U-Boot's dtb >>>>> without simultaneously signing a FIT image. That tool doesn't seem to >>>>> exist, so I stole the necessary pieces from mkimage et al and put it >>>>> in a single .c file. >>>>> >>>>> I'm still working on the details of my proposed "require just k out >>>>> these n required keys" and how it should be implemented, but it will >>>>> probably involve teaching this tool a bunch of new options. These >>>>> patches are not necessarily ready for inclusion (unless someone else >>>>> finds fdt_add_pubkey useful as is), but I thought I might as well send >>>>> it out for early comments. >>>> >>>> I'd also like to see the usage of this hooked into the build process. >>>> >>>> And to my understanding of [1], that approach will provide a feature >>>> that permits hooking with the build but would expect the key as dtsi >>>> fragment. Can we consolidate the approaches? >>>> >>>> My current vision of a user interface would be a Kconfig option that >>>> takes a list of key files to be injected. Maybe make that three lists, >>>> one for "required=image", one for "required=conf", and one for optional >>>> keys (if that has a use case in practice, no idea). >>> >>> Also please take a look at binman which is designed to handle create >>> (or later updating from Yocto) the devicetree or firmware image. >>> >> >> Yes, binman is another problem area, but not for the public key >> injection, rather for permitting to sign fit images that are described >> for binman (rather than for mkimage). I'm currently back to dd for >> signing the U-Boot container in >> arch/arm/dts/k3-am65-iot2050-boot-image.dtsi, or I would have to split >> that FIT image description from that file - both not optimal. > > OK, this can already be optimized with "binman replace" - once I > understood where fdtmap can go and where not. Why no support for using > map files? >
Well, too quick: "binman replace" writes everything into a temporary directory, including the updated image - and then deletes this directory on exit. So the original image will not be updated, and the update is lost. I tried to quickly fix it by adding a rename before FinaliseOutputDir, but it feels like I'm working against the design of the internal interfaces here. Jan -- Siemens AG, T RDA IOT Corporate Competence Center Embedded Linux
