Hi Ian, On Sat, 12 Jul 2014 14:23:41 +0100, Ian Campbell <i...@hellion.org.uk> wrote:
> Hi, > > Marc is rather busy so I've taken it upon myself to rebase this series > onto the latest master. v4 would have been applied except for a warning > which it caused on aarch64 which I have (trivially) resolved this time > around. The only other change is s/OBJCFLAGS/OBJCOPYFLAGS/ due to > changes in the underlying code. > > I'd like to get this into the next merge window since it is the basis > for sunxi smp support. > > I have been testing on a cubietruck (sun7i/A20). I've also build tested > "./MAKEALL -v armltd" which builds a variety of 32- and 64-bit boards. > > The code is also available at > git://gitorious.org/ijc/u-boot.git psci-v5 > > The sunxi patches which build on this are at > git://gitorious.org/ijc/u-boot.git psci-a20-v5 > > Cheers, > Ian. > > Marc's original blurb: > > PSCI is an ARM standard that provides a generic interface that > supervisory software can use to manage power in the following > situations: > - Core idle management > - CPU hotplug > - big.LITTLE migration models > - System shutdown and reset > > It basically allows the kernel to offload these tasks to the firmware, > and rely on common kernel side code that just calls into PSCI. > > More importantly, it gives a way to ensure that CPUs enter the kernel > at the appropriate exception level (ie HYP mode, to allow the use of > the virtualization extensions), even across events like CPUs being > powered off/on or suspended. > > The main idea here is to turn some of the existing U-Boot code into a > separate section that can live in secure RAM (or a reserved page of > memory), containing a secure monitor that will implement the PSCI > operations. This code will still be alive when U-Boot is long gone, > hence the need for a piece of memory that will not be touched by the > OS. > > This patch series contains 3 parts: > - the first four patches are just bug fixes > - the next two refactor the HYP/non-secure code to allow relocation > in secure memory > - the last four contain the generic PSCI code and DT infrastructure > > This implements the original 0.1 spec, as nobody implements the new > 0.2 version so far. I plan to update this support to 0.2 once there is > an official binding available (and support in the kernel). > > Most of the development has been done on an Allwinner A20 SoC, which > is the main user of this code at the moment. I hope new SoCs will be > using this method in the future (my primary goal for this series being > to avoid more stupid SMP code from creeping up in the Linux > kernel). As instructed, I've removed the A20 support code and made it > a separate series, as there is now an effort to mainline this code > (see Ian Campbell patch series). > > With these three series applied, the A20 now boots in HYP mode, Linux > finds the secondary CPU without any SMP code present in the kernel, > and runs KVM out of the box. The Xen/ARM guys managed to do the same > fairly easily, as did at least one XVizor user. > > This code has also been tested on a VExpress TC2, running KVM with all > 5 CPUs, in order to make sure there was no obvious regression. > > Whole series applied to u-boot-arm/master, thanks! Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
