[PATCH 5/6] kexec-bzImage: Support for loading bzImage using 64bit entry
H. Peter Anvin
hpa at zytor.com
Fri Nov 22 10:24:37 EST 2013
On 11/21/2013 11:21 AM, Vivek Goyal wrote:
>> What do you mean by the "real mode entry"? Do we need to care about
>> that because we aren't falling back to real mode when executing this,
>> are we? Or does that just happen for 32bit kernels?
> Original kexec offers real mode entry choice too. So we fall back
> to real mode and jump to kernel and kernel makes bunch of BIOS calls. I
> don't think this is a commonly used option.
I know some users of it (who I shall not name.) In general it is a bad
option, because after running the first kernel the state of the hardware
is not guaranteed to be such that executing the BIOS is safe. In
general, I do think they do it just because they tried at some point and
it happened to work; discouraging its use is probably for the better.
More information about the kexec