On 09/10/2013 02:44 PM, Vivek Goyal wrote: > Currently kexec does not enables EFI and its tables in second kernel. Hence > acpi rsdp root pointer is passed on command line. But secureboot does not trust > acpi_rsdp on command line as kernel can execute some of the code as retrieved > by following acpi_rsdp and root can modify command line. So in secureboot > mode we ignore acpi_rsdp on command line. > > Start passing it in bootparams for the time being. kexec-tools will prepare > the bootparams and put acpi_rsdp pointer there. > > Peter Jones suggested that scan all ACPI memory for acpi_rsdp if EFI is > not enabled. This probably is a better fix and most likely this patch will > change and adopt that approach down the line. > > In fact if we figure out how to make UEFI run time calls in second kernel, > we will not need acpi_rsdp at all. > Borislav Petkov has been working on a fixed mapping of UEFI memory, which should allow UEFI runtime calls across kexec. -hpa
