On 7 May 2013 14:25, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: > On 07/05/13 06:54, Giridhar Maruthy wrote: >> This patch is a modification from the Christoffer Dall's u-boot >> patch. This is required to put the secondary processors in hyp >> mode during cpu hotplug when u-boot is no longer alive. >> >> Marc Zyngier suggested this logic to go into firmware or, u-boot >> putting a trampoline code into a page /memreserve/d by DT. But >> this seemed to have a problem. Once the cpu is hotplugged in >> runtime, the control is in ROM code and waits for event. >> Kernel provides a return address in kernel to which the processor >> jumps once it gets an event. If the control branches to the >> trampoline code here, this trampoline code has no kernel return >> address. >> >> Someone with better logic or better placement of this logic >> elsewhere is welcome. > > What prevents you from writing the kernel address in the memreserved > page? Some obvious location, like the last word of the page? You only > have to do it once (from the boot CPU, for example). > > Or did I miss something else? Thanks Marc, I think I understand now. I guess I also need to put the primary cpu boot mode into a temporary location. -Giridhar _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
