Hi, Some nitpicks inline.. On Thu, Feb 15, 2018 at 5:14 PM, Gioh Kim <gi-oh.kim@xxxxxxxxxxxxxxxx> wrote: > "--load-preserve-context", "--load-jump-back-helper" and "--entry" > options are described separately but there is not any description > how to use them. > > Signed-off-by: Gioh Kim <gi-oh.kim@xxxxxxxxxxxxxxxx> > --- > kexec/kexec.8 | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/kexec/kexec.8 b/kexec/kexec.8 > index e0131b4..b7ac028 100644 > --- a/kexec/kexec.8 > +++ b/kexec/kexec.8 > @@ -30,6 +30,9 @@ when configuring the kernel. The > option enables the > .B kexec > system call. > +After booting into another kernel, you can jump back to the first kernel with enabling I would suggest using the already prevalent naming conventions - primary kernel and secondary kernel for the two kernels. > +.B CONFIG_KEXEC_JUMP > +option (x86 only). I think this is also supported on sh architecture, so may be you can reword this to something like: (currently only x86 and sh architectures are supported). > .SH USAGE > Using > .B kexec > @@ -102,6 +105,30 @@ command: > .BR kexec \ \-e > .RE > > +After booting the kernel, you can jump back to the first kernel if you enable > +.B CONFIG_KEXEC_JUMP > +kernel option and specify \-\-load\-preserve\-context option. Do we need to repeat the details of CONFIG_KEXEC_JUMP here and below, as we have already the captured the same above. > +You can see ^^^ specify (instead of see) > +.BR "kexec_jump_back_entry=<address>" > +kernel parameter in /proc/cmdline file, for example: > + > +.RS > +.BR "kexec_jump_back_entry=0x00000000000810d2" Better to specify literal addr instead of specifying a value here. > +.RE > + > +Frist you need to prepare jump with \-\-load\-jump\-back\-helper and \-\-entry options. ^^^ First (rather than Frist) > + > +.RS > +.B kexec > +.RB \-\-load\-jump\-back\-helper \-\-entry=0x810d2 Better to use literal addr instead of specifying a particular value here, to keep the man page generic. Regards, Bhupesh > +.RE > + > +Then the first kernel can be rebooted using the command: > + > +.RS > +.BR kexec \ \-e > +.RE > + > .SH OPTIONS > .TP > .B \-d\ (\-\-debug) > @@ -173,6 +200,9 @@ Specify the jump back address. (0 means it's not jump back or preserve context) > .TP > .BI \-\-load\-preserve\-context > Load the new kernel and preserve context of current kernel during kexec. > +(kexec returns error if > +.B CONFIG_KEXEC_JUMP > +is not enabled) > .TP > .BI \-\-load\-jump\-back\-helper > Load a helper image to jump back to original kernel. > -- > 2.14.1 > _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec