path: root/arch/x86_64
diff options
authorRafael J. Wysocki <rjw@sisk.pl>2007-10-18 03:04:53 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-18 14:37:19 -0700
commitd158cbdf39ffaec9dd5299fdfdfdd2c7897a71dc (patch)
tree1a03042426b7469c06403a5e5615bc81d3ad1d1a /arch/x86_64
parentd307c4a8e826c44f9633bd3f7e60d0491e7d885a (diff)
Hibernation: Arbitrary boot kernel support on x86_64
Make it possible to restore a hibernation image on x86_64 with the help of a kernel different from the one in the image. The idea is to split the core restoration code into two separate parts and to place each of them in a different page.  The first part belongs to the boot kernel and is executed as the last step of the image kernel's memory restoration procedure.  Before being executed, it is relocated to a safe page that won't be overwritten while copying the image kernel pages. The final operation performed by it is a jump to the second part of the core restoration code that belongs to the image kernel and has just been restored. This code makes the CPU switch to the image kernel's page tables and restores the state of general purpose registers (including the stack pointer) from before the hibernation. The main issue with this idea is that in order to jump to the second part of the core restoration code the boot kernel needs to know its address.  However, this address may be passed to it in the image header.  Namely, the part of the image header previously used for checking if the version of the image kernel is correct can be replaced with some architecture specific data that will allow the boot kernel to jump to the right address within the image kernel.  These data should also be used for checking if the image kernel is compatible with the boot kernel (as far as the memory restroration procedure is concerned). It can be done, for example, with the help of a "magic" value that has to be equal in both kernels, so that they can be regarded as compatible. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86_64')
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 43fafe9e9c08..78cb68f2ebbd 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -716,6 +716,11 @@ menu "Power management options"
source kernel/power/Kconfig
+ bool
+ depends on HIBERNATION
+ default y
source "drivers/acpi/Kconfig"
source "arch/x86/kernel/cpufreq/Kconfig"