Re: TFPT boot without PXE

[Andrei Borzenkov]

On Tue, Jul 28, 2015 at 10:25 AM, Christian Meyer <address@hidden> wrote:
> Am Sonntag, den 26.07.2015, 08:07 +0300 schrieb Andrei Borzenkov:
>> В Sun, 26 Jul 2015 00:14:48 +0200
>> Christian Meyer <address@hidden> пишет:
>>
>> > is there a way to locally start grub (via hd, CD or USB) and let it boot
>> > a GNU/Linux system over the network only using TFTP (with given
>> > servername or IP adress) but without using PXE?
>> >
>>
>> GRUB is using networking facilities provided by firmware so it depends
>> on platform. On UEFI networking is always available so it is possible.
>> On legacy BIOS (i.e. i386-pc) PXE stack is present only when booted
>> over PXE, so it is not possible.
>
> That are (half) good news. Some of my computers are based on legacy
> BIOS, so there is no good hope.
>
> For the most ones (UEFI) it should work.
> Can you please give me a hint about the invokation in grub.cfg?
> Especially about how to define the server IP?

GRUB is using common syntax for device names, to load file over network use

(tftp,<ip-or-host-name>)/path/to/file

of course host name is possible only when DNS is set up. So something
like (tftp,192.168.1.1)/boot/linux

To configure network on UEFI

insmod efinet - loads driver

net_ls_cards - lists all detected physical NICs presented by firmware
net_add_addr <addr-name> <card> <IP> - adds address <IP> to card
<card> (from pevious list) and labels it as <addr-name>

you also may need to configure routing. See
http://dev.gentoo.org/~floppym/grub.html#Networking-commands for
up-to-date documentation for these commands.