diff options
author | Vivek Goyal <vgoyal@in.ibm.com> | 2007-01-05 16:36:30 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.osdl.org> | 2007-01-05 23:55:23 -0800 |
commit | dd0ec16fa6cf2498b831663a543e1b67fce6e155 (patch) | |
tree | 6b91a5ff9713c83f6026d1198be98f7ed1e845e6 /arch | |
parent | a75acf850ca80136a4f845cf9a7cd26e7465c1f4 (diff) |
[PATCH] i386: Restore CONFIG_PHYSICAL_START option
o Relocatable bzImage support had got rid of CONFIG_PHYSICAL_START option
thinking that now this option is not required as people can build a
second kernel as relocatable and load it anywhere. So need of compiling
the kernel for a custom address was gone. But Magnus uses vmlinux images
for second kernel in Xen environment and he wants to continue to use
it.
o Restoring the CONFIG_PHYSICAL_START option for the time being. I think
down the line we can get rid of it.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/i386/Kconfig | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig index 0d67a0a1151e..0dfee812811a 100644 --- a/arch/i386/Kconfig +++ b/arch/i386/Kconfig @@ -777,6 +777,47 @@ config CRASH_DUMP PHYSICAL_START. For more details see Documentation/kdump/kdump.txt +config PHYSICAL_START + hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) + default "0x100000" + help + This gives the physical address where the kernel is loaded. + + If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then + bzImage will decompress itself to above physical address and + run from there. Otherwise, bzImage will run from the address where + it has been loaded by the boot loader and will ignore above physical + address. + + In normal kdump cases one does not have to set/change this option + as now bzImage can be compiled as a completely relocatable image + (CONFIG_RELOCATABLE=y) and be used to load and run from a different + address. This option is mainly useful for the folks who don't want + to use a bzImage for capturing the crash dump and want to use a + vmlinux instead. vmlinux is not relocatable hence a kernel needs + to be specifically compiled to run from a specific memory area + (normally a reserved region) and this option comes handy. + + So if you are using bzImage for capturing the crash dump, leave + the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y. + Otherwise if you plan to use vmlinux for capturing the crash dump + change this value to start of the reserved region (Typically 16MB + 0x1000000). In other words, it can 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. + + Usage of bzImage for capturing the crash dump is recommended as + one does not have to build two kernels. Same kernel can be used + as production kernel and capture kernel. Above option should have + gone away after relocatable bzImage support is introduced. But it + is present because there are users out there who continue to use + vmlinux for dump capture. This option should go away down the + line. + + Don't change this unless you know what you are doing. + config RELOCATABLE bool "Build a relocatable kernel(EXPERIMENTAL)" depends on EXPERIMENTAL |