From: Simon Horman Patch from Mohan Kumar M to add the ppc64 portions of the kdump documentation. http://thread.gmane.org/gmane.linux.kernel/481689/focus=3375 Cc: Mohan Kumar M Cc: Vivek Goyal Signed-off-by: Simon Horman Cc: Paul Mackerras Signed-off-by: Andrew Morton --- Documentation/kdump/kdump.txt | 24 +++++++++++++----------- 1 files changed, 13 insertions(+), 11 deletions(-) diff -puN Documentation/kdump/kdump.txt~ppc64-kdump-documentation-update-for-2620 Documentation/kdump/kdump.txt --- a/Documentation/kdump/kdump.txt~ppc64-kdump-documentation-update-for-2620 +++ a/Documentation/kdump/kdump.txt @@ -30,6 +30,10 @@ On x86 machines, the first 640 KB of phy regardless of where the kernel loads. Therefore, kexec backs up this region just before rebooting into the dump-capture kernel. +Similarly on PPC64 machines first 32KB of physical memory is needed for +booting regardless of where the kernel is loaded and to support 64K page +size kexec backs up the first 64KB memory. + All of the necessary information about the system kernel's core image is encoded in the ELF format, and stored in a reserved area of memory before a crash. The physical address of the start of the ELF header is @@ -224,7 +228,7 @@ Dump-capture kernel config options (Arch Dump-capture kernel config options (Arch Dependent, ppc64) ---------------------------------------------------------- -- Make and install the kernel and its modules. DO NOT add this kernel +* Make and install the kernel and its modules. DO NOT add this kernel to the boot loader configuration files. Dump-capture kernel config options (Arch Dependent, ia64) @@ -251,8 +255,8 @@ Dump-capture kernel config options (Arch Boot into System Kernel ======================= -1) Make and install the kernel and its modules. Update the boot loader - (such as grub, yaboot, or lilo) configuration files as necessary. +1) Update the boot loader (such as grub, yaboot, or lilo) configuration + files as necessary. 2) Boot the system kernel with the boot parameter "crashkernel=Y@X", where Y specifies how much memory to reserve for the dump-capture kernel @@ -356,10 +360,11 @@ If die() is called, and it happens to be is called inside interrupt context or die() is called and panic_on_oops is set, the system will boot into the dump-capture kernel. -On powererpc systems when a soft-reset is generated, die() is called by all cpus and the system will boot into the dump-capture kernel. +On powererpc systems when a soft-reset is generated, die() is called by all cpus +and the system will boot into the dump-capture kernel. For testing purposes, you can trigger a crash by using "ALT-SysRq-c", -"echo c > /proc/sysrq-trigger or write a module to force the panic. +"echo c > /proc/sysrq-trigger" or write a module to force the panic. Write Out the Dump File ======================= @@ -410,12 +415,9 @@ format. Crash is available on Dave Ander To Do ===== -1) Provide a kernel pages filtering mechanism, so core file size is not - extreme on systems with huge memory banks. - -2) Relocatable kernel can help in maintaining multiple kernels for - crash_dump, and the same kernel as the system kernel can be used to - capture the dump. +1) Provide relocatable kernels for all architectures to help in maintaining + multiple kernels for crash_dump, and the same kernel as the system kernel + can be used to capture the dump. Contact _