[PATCH] i386: Implement CONFIG_PHYSICAL_ALIGN

[deliverable/linux.git] / arch / i386 / Kconfig

diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index d588ca874bb4e296efeeec20e0a35795a7276441..fd2fa7a7ec52075514d5f21f651ca502401ebe1b 100644 (file)
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -785,23 +785,26 @@ config RELOCATABLE
           must live at a different physical address than the primary
           kernel.
 
-config PHYSICAL_START
-       hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
-
-       default "0x1000000" if CRASH_DUMP
+config PHYSICAL_ALIGN
+       hex "Alignment value to which kernel should be aligned"
        default "0x100000"
+       range 0x2000 0x400000
        help
-         This gives the physical address where the kernel is loaded. Normally
-         for regular kernels this value is 0x100000 (1MB). But in the case
-         of kexec on panic the fail safe kernel needs to run at a different
-         address than the panic-ed kernel. This option is used to set the load
-         address for kernels used to capture crash dump on being kexec'ed
-         after panic. The default value for crash dump kernels is
-         0x1000000 (16MB). This can also be set based on the "X" value as
-         specified in the "crashkernel=YM@XM" command line boot parameter
-         passed to the panic-ed kernel. Typically this parameter is set as
-         crashkernel=64M@16M. Please take a look at
-         Documentation/kdump/kdump.txt for more details about crash dumps.
+         This value puts the alignment restrictions on physical address
+         where kernel is loaded and run from. Kernel is compiled for an
+         address which meets above alignment restriction.
+
+         If bootloader loads the kernel at a non-aligned address and
+         CONFIG_RELOCATABLE is set, kernel will move itself to nearest
+         address aligned to above value and run from there.
+
+         If bootloader loads the kernel at a non-aligned address and
+         CONFIG_RELOCATABLE is not set, kernel will ignore the run time
+         load address and decompress itself to the address it has been
+         compiled for and run from there. The address for which kernel is
+         compiled already meets above alignment restrictions. Hence the
+         end result is that kernel runs from a physical address meeting
+         above alignment restrictions.
 
          Don't change this unless you know what you are doing.