On Thu, Aug 14, 2014 at 05:55:32PM +0800, HuKeping wrote: > ---------------------------------------- > > Add arm specific parts to kdump kernel documentation. > > v2 -> v3 > - fix some spelling mistakes > > Signed-off-by: Hu Keping <hukeping at huawei.com> > --- Acked-by: Vivek Goyal <vgoyal at redhat.com> Vivek > Documentation/kdump/kdump.txt | 36 +++++++++++++++++++++++++++++++++--- > 1 file changed, 33 insertions(+), 3 deletions(-) > > diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt > index 9c7fd988..8c632db 100644 > --- a/Documentation/kdump/kdump.txt > +++ b/Documentation/kdump/kdump.txt > @@ -18,7 +18,7 @@ memory image to a dump file on the local disk, or across the network to > a remote system. > > Kdump and kexec are currently supported on the x86, x86_64, ppc64, ia64, > -and s390x architectures. > +s390x and arm architectures. > > When the system kernel boots, it reserves a small section of memory for > the dump-capture kernel. This ensures that ongoing Direct Memory Access > @@ -119,7 +119,7 @@ There are two possible methods of using Kdump. > 2) Or use the system kernel binary itself as dump-capture kernel and there is > no need to build a separate dump-capture kernel. This is possible > only with the architectures which support a relocatable kernel. As > - of today, i386, x86_64, ppc64 and ia64 architectures support relocatable > + of today, i386, x86_64, ppc64, ia64 and arm architectures support relocatable > kernel. > > Building a relocatable kernel is advantageous from the point of view that > @@ -248,6 +248,13 @@ Dump-capture kernel config options (Arch Dependent, ia64) > kernel will be aligned to 64Mb, so if the start address is not then > any space below the alignment point will be wasted. > > +Dump-capture kernel config options (Arch Dependent, arm) > +---------------------------------------------------------- > + > +- To use a relocatable kernel, > + Enable "AUTO_ZRELADDR" support under "Boot" options: > + > + AUTO_ZRELADDR=y > > Extended crashkernel syntax > =========================== > @@ -263,6 +270,10 @@ The syntax is: > crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset] > range=start-[end] > > +Please note, on arm, the offset is required. > + crashkernel=<range1>:<size1>[,<range2>:<size2>,...]@offset > + range=start-[end] > + > 'start' is inclusive and 'end' is exclusive. > > For example: > @@ -303,6 +314,12 @@ Boot into System Kernel > on the memory consumption of the kdump system. In general this is not > dependent on the memory size of the production system. > > + On arm, use "crashkernel=Y at X". Note that the start address of the kernel > + will be aligned to 128MiB (0x08000000), so if the start address is not then > + any space below the alignment point may be overwritten by the dump-capture kernel, > + which means it is possible that the vmcore is not that precise as expected. > + > + > Load the Dump-capture Kernel > ============================ > > @@ -322,7 +339,8 @@ For ia64: > - Use vmlinux or vmlinuz.gz > For s390x: > - Use image or bzImage > - > +For arm: > + - Use zImage > > If you are using a uncompressed vmlinux image then use following command > to load dump-capture kernel. > @@ -338,6 +356,15 @@ to load dump-capture kernel. > --initrd=<initrd-for-dump-capture-kernel> \ > --append="root=<root-dev> <arch-specific-options>" > > +If you are using a compressed zImage, then use following command > +to load dump-capture kernel. > + > + kexec --type zImage -p <dump-capture-kernel-bzImage> \ > + --initrd=<initrd-for-dump-capture-kernel> \ > + --dtb=<dtb-for-dump-capture-kernel> \ > + --append="root=<root-dev> <arch-specific-options>" > + > + > Please note, that --args-linux does not need to be specified for ia64. > It is planned to make this a no-op on that architecture, but for now > it should be omitted > @@ -354,6 +381,9 @@ For ppc64: > For s390x: > "1 maxcpus=1 cgroup_disable=memory" > > +For arm: > + "1 maxcpus=1 reset_devices" > + > Notes on loading the dump-capture kernel: > > * By default, the ELF headers are stored in ELF64 format to support > -- > 1.8.5.5
