diff options
-rw-r--r-- | Documentation/kdump/kdump.txt | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt index 79775a4130b5..2fedc081b4c8 100644 --- a/Documentation/kdump/kdump.txt +++ b/Documentation/kdump/kdump.txt | |||
@@ -30,6 +30,10 @@ On x86 machines, the first 640 KB of physical memory is needed to boot, | |||
30 | regardless of where the kernel loads. Therefore, kexec backs up this | 30 | regardless of where the kernel loads. Therefore, kexec backs up this |
31 | region just before rebooting into the dump-capture kernel. | 31 | region just before rebooting into the dump-capture kernel. |
32 | 32 | ||
33 | Similarly on PPC64 machines first 32KB of physical memory is needed for | ||
34 | booting regardless of where the kernel is loaded and to support 64K page | ||
35 | size kexec backs up the first 64KB memory. | ||
36 | |||
33 | All of the necessary information about the system kernel's core image is | 37 | All of the necessary information about the system kernel's core image is |
34 | encoded in the ELF format, and stored in a reserved area of memory | 38 | encoded in the ELF format, and stored in a reserved area of memory |
35 | before a crash. The physical address of the start of the ELF header is | 39 | before a crash. The physical address of the start of the ELF header is |
@@ -224,7 +228,7 @@ Dump-capture kernel config options (Arch Dependent, x86_64) | |||
224 | Dump-capture kernel config options (Arch Dependent, ppc64) | 228 | Dump-capture kernel config options (Arch Dependent, ppc64) |
225 | ---------------------------------------------------------- | 229 | ---------------------------------------------------------- |
226 | 230 | ||
227 | - Make and install the kernel and its modules. DO NOT add this kernel | 231 | * Make and install the kernel and its modules. DO NOT add this kernel |
228 | to the boot loader configuration files. | 232 | to the boot loader configuration files. |
229 | 233 | ||
230 | Dump-capture kernel config options (Arch Dependent, ia64) | 234 | Dump-capture kernel config options (Arch Dependent, ia64) |
@@ -251,8 +255,8 @@ Dump-capture kernel config options (Arch Dependent, ia64) | |||
251 | Boot into System Kernel | 255 | Boot into System Kernel |
252 | ======================= | 256 | ======================= |
253 | 257 | ||
254 | 1) Make and install the kernel and its modules. Update the boot loader | 258 | 1) Update the boot loader (such as grub, yaboot, or lilo) configuration |
255 | (such as grub, yaboot, or lilo) configuration files as necessary. | 259 | files as necessary. |
256 | 260 | ||
257 | 2) Boot the system kernel with the boot parameter "crashkernel=Y@X", | 261 | 2) Boot the system kernel with the boot parameter "crashkernel=Y@X", |
258 | where Y specifies how much memory to reserve for the dump-capture kernel | 262 | 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 a thread with pid 0 or 1, or die() | |||
356 | is called inside interrupt context or die() is called and panic_on_oops is set, | 360 | is called inside interrupt context or die() is called and panic_on_oops is set, |
357 | the system will boot into the dump-capture kernel. | 361 | the system will boot into the dump-capture kernel. |
358 | 362 | ||
359 | 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. | 363 | On powererpc systems when a soft-reset is generated, die() is called by all cpus |
364 | and the system will boot into the dump-capture kernel. | ||
360 | 365 | ||
361 | For testing purposes, you can trigger a crash by using "ALT-SysRq-c", | 366 | For testing purposes, you can trigger a crash by using "ALT-SysRq-c", |
362 | "echo c > /proc/sysrq-trigger or write a module to force the panic. | 367 | "echo c > /proc/sysrq-trigger" or write a module to force the panic. |
363 | 368 | ||
364 | Write Out the Dump File | 369 | Write Out the Dump File |
365 | ======================= | 370 | ======================= |
@@ -410,12 +415,9 @@ format. Crash is available on Dave Anderson's site at the following URL: | |||
410 | To Do | 415 | To Do |
411 | ===== | 416 | ===== |
412 | 417 | ||
413 | 1) Provide a kernel pages filtering mechanism, so core file size is not | 418 | 1) Provide relocatable kernels for all architectures to help in maintaining |
414 | extreme on systems with huge memory banks. | 419 | multiple kernels for crash_dump, and the same kernel as the system kernel |
415 | 420 | can be used to capture the dump. | |
416 | 2) Relocatable kernel can help in maintaining multiple kernels for | ||
417 | crash_dump, and the same kernel as the system kernel can be used to | ||
418 | capture the dump. | ||
419 | 421 | ||
420 | 422 | ||
421 | Contact | 423 | Contact |