Re: Unknown command 'else'?

[Andrei Borzenkov]

18.09.2015 18:38, Steven Shiau пишет:
> On 2015年09月18日 20:16, Andrei Borzenkov wrote:
> > On Fri, Sep 18, 2015 at 12:47 PM, Steven Shiau <address@hidden> wrote:
> > > If there is someway to make this if/elif/else/fi work in embedded config,
> >
> > I do not think it is likely to happen. It will increase size of core
> > and we attempt to keep it as small as possible. Given that easy
> > solution (grub-mkstandalone) already exists, there is no compelling
> > reason to do it either.
> Thanks.
>  From my understanding, it seems the image created by "grub-mkstandalone"
> can not load the grub config file from tftp server?  Because I tried to
> assign the config file on tftp server (as in my previous post), but it
> can not read the config file from tftp server.
> Am I right?

It can read, just that it is configured with $root and $prefix pointing 
to internal memory, so it does not do it by default. But you still have 
$cmdpath that points to original boot location and you still have 
$net_default_server, $net_default_mac etc which should point to TFTP 
server it had been booted from. So you should be able to write custom 
grub.cfg making use of them.

Of course you need to preload net and driver modules, just like netboot 
image does, to compute them.

> If so, then "grub-mkstandalone" won't work for my purpose,
> because the grub config file for uEFI network booting might be changed
> for each client (like grub.cfg-01:$net_default_mac) on the server so
> that the client machine's booting mechanism can be changed to what the
> system administrator wants. It's not handy to create the standalone boot
> image every time with grub-mkstandalone because there might be more than
> 2 clients, and we need to have different booting mechanism for each client.
> So, from your previous post
> (http://lists.gnu.org/archive/html/help-grub/2015-09/msg00044.html), it
> occurred to me that if I make my way like this:
> 1. Make the content of /tmp/grub-efi/grub-header.cfg as:
> =============================
> set prefix=(tftp)/grub-efi.cfg
> echo 'Network status: '
> net_ls_cards
> net_ls_addr
> net_ls_routes
>
> echo "Use config file: $prefix/grub.cfg-01:$net_default_mac"
> configfile $prefix/grub.cfg-01:$net_default_mac
>
> echo "Use config file: $prefix/grub.cfg"
> configfile $prefix/grub.cfg
>
> echo "Could not find config file $prefix/grub.cfg-$net_default_mac or
> $prefix/grub.cfg!"
> sleep 15
> =============================
>
> 2. The command to create the image:
> grub-mkimage -C xz -O x86_64-efi -o /tftpboot/nbi_img/bootx64.efi
> --prefix='(tftp)/grub-efi.cfg/' -c /tmp/grub-efi/grub-header.cfg normal
> tftp efinet chain echo net gzio xzio linux efi_gop efi_uga png gfxterm
> gfxterm_background gfxterm_menu serial part_gpt part_msdos boot
> multiboot progress search reboot halt configfile test sleep
>
> Then no error at all, and it also works.  Looks pretty cool?
> Do you think this preconfig file will work for the future grub 2.x?

Yes, I do not really expect it to break. May be just become more verbose 
with errors about missing files.

> Thank you very much.
>
> Steven.