tree 924944ad2dc7fd456e6ce6c097e552bfebacabf6
parent 1765a367a3b5d5e9692949b0c5ec933eff2c0701
author Takao Indoh <indou.takao@jp.fujitsu.com> 1310681121 -0400
committer Len Brown <len.brown@intel.com> 1310856016 -0400

ACPI: introduce "acpi_rsdp=" parameter for kdump

There is a problem with putting the first kernel in EFI virtual mode,
it is that when the second kernel comes up it tries to initialize the
EFI again and once we have put EFI in virtual mode we can not really
do that.

Actually, EFI is not necessary for kdump, we can boot the second kernel
with "noefi" parameter, but the boot will mostly fail because 2nd kernel
cannot find RSDP.

In this situation, we introduced "acpi_rsdp=" kernel parameter, so that
kexec-tools can pass the "noefi acpi_rsdp=X" to the second kernel to
make kdump works. The physical address of the RSDP can be got from
sysfs(/sys/firmware/efi/systab).

Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com>
Reviewed-by: WANG Cong <amwang@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Len Brown <len.brown@intel.com>