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@@ -30,6 +30,10 @@ On x86 machines, the first 640 KB of physical memory is needed to boot,
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regardless of where the kernel loads. Therefore, kexec backs up this
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region just before rebooting into the dump-capture kernel.
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+Similarly on PPC64 machines first 32KB of physical memory is needed for
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+booting regardless of where the kernel is loaded and to support 64K page
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+size kexec backs up the first 64KB memory.
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+
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All of the necessary information about the system kernel's core image is
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encoded in the ELF format, and stored in a reserved area of memory
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before a crash. The physical address of the start of the ELF header is
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@@ -224,7 +228,7 @@ Dump-capture kernel config options (Arch Dependent, x86_64)
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Dump-capture kernel config options (Arch Dependent, ppc64)
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----------------------------------------------------------
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-- Make and install the kernel and its modules. DO NOT add this kernel
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+* Make and install the kernel and its modules. DO NOT add this kernel
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to the boot loader configuration files.
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Dump-capture kernel config options (Arch Dependent, ia64)
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@@ -251,8 +255,8 @@ Dump-capture kernel config options (Arch Dependent, ia64)
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Boot into System Kernel
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=======================
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-1) Make and install the kernel and its modules. Update the boot loader
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- (such as grub, yaboot, or lilo) configuration files as necessary.
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+1) Update the boot loader (such as grub, yaboot, or lilo) configuration
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+ files as necessary.
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2) Boot the system kernel with the boot parameter "crashkernel=Y@X",
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where Y specifies how much memory to reserve for the dump-capture kernel
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@@ -356,10 +360,11 @@ If die() is called, and it happens to be a thread with pid 0 or 1, or die()
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is called inside interrupt context or die() is called and panic_on_oops is set,
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the system will boot into the dump-capture kernel.
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-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.
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+On powererpc systems when a soft-reset is generated, die() is called by all cpus
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+and the system will boot into the dump-capture kernel.
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For testing purposes, you can trigger a crash by using "ALT-SysRq-c",
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-"echo c > /proc/sysrq-trigger or write a module to force the panic.
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+"echo c > /proc/sysrq-trigger" or write a module to force the panic.
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Write Out the Dump File
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=======================
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@@ -410,12 +415,9 @@ format. Crash is available on Dave Anderson's site at the following URL:
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To Do
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=====
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-1) Provide a kernel pages filtering mechanism, so core file size is not
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- extreme on systems with huge memory banks.
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-
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-2) Relocatable kernel can help in maintaining multiple kernels for
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- crash_dump, and the same kernel as the system kernel can be used to
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- capture the dump.
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+1) Provide relocatable kernels for all architectures to help in maintaining
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+ multiple kernels for crash_dump, and the same kernel as the system kernel
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+ can be used to capture the dump.
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Contact
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