Hi Simon,
2017-12-12 13:38 GMT+09:00 Simon Glass <[email protected]>: > Hi Andre, > > On 3 December 2017 at 19:05, Andre Przywara <[email protected]> wrote: >> The DT spec[1] demands a unit-address in a node name (name@address) to >> match the "reg" property inside that node: >> uart0: serial@1c28000 { >> reg = <0x01c28000 0x400>; >> .... >> If there is no reg property in a node, there must not be a unit address >> in the node name as well (so no '@' sign at all). >> >> Newer version of the device tree compiler (dtc) will warn about violations >> of this rule: >> .... >> <stdout>: Warning (unit_address_vs_reg): Node /images/fdt@1 has a unit name, >> but no reg property >> .... >> >> To avoid those warnings, but still keep enumerable node names, we replace >> the "@" sign with a dash ("-"), which does not have a specical meaning, >> but is a valid node name character. So the first fdt file (as referenced >> above in the warning message) would be called "fdt-1" instead. >> >> This affects mostly documenation files and some examples of FIT image >> files, but also some code which actually generates FIT images: >> - The first four patches fix documentation, example files and comments, >> they should not affect actual generated code or files. >> In places where having multiple instances of a node is normal (fdt, >> hash, signature), I simply replaced the '@' sign with the dash. >> Where one would expect only one instance (kernel, initrd), I removed the >> bogus '@1' completely, so a "kernel" just goes by just this very name. >> - Patch 5/7 fixes the usage in the Allwinner SPL FIT image files, this has >> been on the list before. >> - Patch 6/7 fixes the usage when the mkimage tool (auto-)generates FIT >> images. >> - The final patch 7/7 fixes the usage for the ARMv8 secure firmware image >> handling. I am a bit unsure about this one, as this seems to *look* for >> a specific node name, which sounds a bit dodgy to me. I think DT parsers >> should never rely on a certain node name, but either use references or look >> inside nodes to find a matching one. Also I am not sure who actually >> generates those FIT image files this code gets to read. Any input would >> be welcome here. >> >> Please let me know if this makes some sense or not. > > I thought I read somewhere that there is a dtc option to turn off > these warnings? > I think -Wno-unit_address_vs_reg is the one, but I prefer to fix the root cause by replacing @ instead of hiding it. -- Best Regards Masahiro Yamada _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
