diff options
Diffstat (limited to 'arch/i386/Kconfig')
| -rw-r--r-- | arch/i386/Kconfig | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig index d588ca874bb4..fd2fa7a7ec52 100644 --- 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. |