This can be useful in particular in the kernel when booting on systems with FDT-emitting firmware that is out of date. Releases of kexec-tools on ppc64 prior to the end of 2014 are notable examples of such.
The limitation to the read-only support is that the fdt_get_property() API is intrinsically incompatible with older versions of the device tree as a result of the 8-byte alignment of properties, so will return BADVERSION. The fdt_getprop() variant is, however, supported on the older structures.
nwhitehorn
commented
6 years ago
This can be useful in particular in the kernel when booting on systems with FDT-emitting firmware that is out of date. Releases of kexec-tools on ppc64 prior to the end of 2014 are notable examples of such.
The limitation to the read-only support is that the fdt_get_property() API is intrinsically incompatible with older versions of the device tree as a result of the 8-byte alignment of properties, so will return BADVERSION. The fdt_getprop() variant is, however, supported on the older structures.