On Tue, Nov 11, 2025 at 01:47:01PM +0000, Simon Horman wrote: > On Wed, Oct 22, 2025 at 07:16:05PM +0530, Shivang Upadhyay wrote: > > Currently, on ppc64 systems, kexec cannot directly use a > > user-provided devicetreeblob (dtb) when booting a new > > kernel with an initrd. This limitation exists because the > > dtb must be modified at runtime — for example, to include > > the initrd’s memory location and size, and to add > > /memreserve/ entries based on the current system memory > > layout. > > > > Previously, kexec handled this by generating a fresh dtb in > > memory from the running system’s /proc/device-tree directory. > > However, this approach prevents users from making > > intentional modifications to the dtb — such as changin boot > > arguments, enabling or disabling devices, or testing kernel > > changes that depend on specific device tree properties. > > > > Adding support for user-provided dtb (with appropriate > > patching by kexec) allows more control for developers, > > particularly when experimenting with custom kernels or > > hardware configurations. > > > > This patch series lifts this restriction and ensures that > > the necessary /memreserve/ sections are properly added to > > the new DTB. on ppc64, it is mandatory, for the rebooting > > cpu to be present in the new kernel’s dtb, so additional > > logic has been added to identify and mark one of available > > cpu as reboot cpu on currect system. > > > > A new architecture-specific function, arch_do_unload(), has > > been introduced to perform the necessary cleanup during > > kexec unload. in ppc64, the reboot CPU changes due to kexec, > > and it gets reset back on kexec unload. > > > > Shivang Upadhyay (4): > > ppc64: ensure /memreserve/ sections exist in user-provided FDT > > ppc64: handle reboot CPU in case of user provided DTB > > Add arch_do_unload hook for arch-specific cleanup > > ppc64: life the dtb and initrd restriction > > Thanks, applied. Thanks Simon
~Shivang.
