On Mon, Aug 27, 2007 at 02:18:49PM +0800, Huang, Ying wrote: [..] > > > > If one compiles the kernel C to boot from reserved memory area (subset > > of memory area used by kernel B), then I can skip the step of kexecing > > from C to D? (COFIG_PHYSICAL_START) > > Yes. I think so. > > > Alternatively, can we give hint to kernel C to run from a specified address > > at run time with the help of command line parameters. What I mean boot-loader > > can load the kernel at any address, but kernel will move itself to run > > from a different location depending on command line parameter. For example, > > let say kernel_run_addr = 0x1000000. This parameter will tell the kernel > > to move itself to 16MB address and run from there. I think it can be made > > to work with little work in existing setup of relocatable kernel. > > > > Kernel run address can be put by some user space script which will save > > the hibernated image of original kernel. So after saving the /proc/vmcore, > > script can modify the boot loader config file to append the right > > command line to the kernel (kernel_run_addr). > > > > After hibernation, user will shutdown/reboot. Next time the kernel boots > > it will load at 16MB addr (because of kernel_run_addr) and then it can > > restore the previously saved image. > > > > We shall have to get rid of (kernel_run_addr) parameter from command > > line while resuming. One can restore the image (krestore) and then edit > > the boot loader config file to get rid of command line param, kernel_run_addr. > > > > In this scheme, with the help of relocatable kernel, we can use a single > > kernel for everything. (A, B, C, D). We will also avoid additional kexec > > from kernel C to kernel D. > > > > I think in the long run we shall have to work out so that a user does > > not have to maintain multiple kernels. > > Only one relocatable kernel image is needed. In fact, I use one > relocatable kernel image in testing during development. > > > Does this make sense? > > Yes, this is a sensible optimization. But I think it may be better to > make bootloader load kernel D directly into a specified memory location. > For example, we can add a option to "kernel" command of grub. > IIUC, you mean a command line option which is parsed by boot-loader and then boot-loader loads the kernel at user specified address? I think it might not be a very good idea as hibernation becomes boot-loader dependent scheme. How many boot-loaders will one modify and hibernation will not work with older versions of boot-loader. I think it is better to make kernel relocate to user specified address and keep hibernation mechanism independent of specific boot-loader(grup, lilo,...) and boot-loader version. Thanks Vivek _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
