[grub]: Allow ONiE oneshot boot for FW update

[nazariig]

Signed-off-by: Nazarii Hnydyn nazariig@mellanox.com

This small improvement enables ONiE oneshoot boot for various firmware update operations
(BIOS, CPLD, etc.):
https://opencomputeproject.github.io/onie/design-spec/firmware_update.html

The new flow allows to avoid the certain types of issues:

root@sonic:/home/admin# sonic_installer list
Current: SONiC-OS-HEAD.140-fc36ca6e
Next: SONiC-OS-HEAD.140-fc36ca6e
Available:
SONiC-OS-HEAD.140-fc36ca6e
SONiC-OS-HEAD.5-386619ac
root@sonic:/home/admin# grub-editenv /host/grub/grubenv set next_entry=2
root@sonic:/home/admin# sonic_installer list
Traceback (most recent call last):
  File "/usr/bin/sonic_installer", line 12, in <module>
    sys.exit(cli())
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 722, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 697, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 1066, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 895, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 535, in invoke
    return callback(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/sonic_installer/main.py", line 380, in list
    nextimage = get_next_image()
  File "/usr/lib/python2.7/dist-packages/sonic_installer/main.py", line 194, in get_next_image
    next_image = images[next_image_index]
IndexError: list index out of range

Example:

root@sonic:/home/admin# sonic_installer list
Current: SONiC-OS-HEAD.140-fc36ca6e
Next: SONiC-OS-HEAD.140-fc36ca6e
Available:
SONiC-OS-HEAD.140-fc36ca6e
SONiC-OS-HEAD.5-386619ac
root@sonic:/home/admin# grub-editenv /host/grub/grubenv set onie_entry=2
root@sonic:/home/admin# sonic_installer set_next_boot SONiC-OS-HEAD.5-386619ac
Command: grub-reboot --boot-directory=/host 1
root@sonic:/home/admin# grub-editenv /host/grub/grubenv list
saved_entry=0
next_entry=1
onie_entry=2
root@sonic:/home/admin# sonic_installer list
Current: SONiC-OS-HEAD.140-fc36ca6e
Next: SONiC-OS-HEAD.5-386619ac
Available:
SONiC-OS-HEAD.140-fc36ca6e
SONiC-OS-HEAD.5-386619ac

- What I did

• Added ONiE oneshoot boot feature

- How I did it

• Modified grub configuration

- How to verify it

1. grub-editenv /host/grub/grubenv set onie_entry=<onie_entry_index>

- Description for the changelog

• N/A

- A picture of a cute animal (not mandatory but encouraged)

      .---.        .-----------
     /     \  __  /    ------
    / /     \(  )/    -----
   //////   ' \/ `   ---
  //// / // :    : ---
 // /   /  /`    '--
//          //..\\
       ====UU====UU====
           '//||\\`
             ''``

[lguohan]

cannot find the onie_entry spec in the url provided above. can you point out the link to the onie_entry?

[nazariig]

cannot find the onie_entry spec in the url provided above. can you point out the link to the onie_entry?

There is no official spec for this naming convention. It's just a proposal to introduce a separate Grub environment variable to control oneshoot boot for FW update. This approach allows to avoid user accident modification of next boot partition.

[nazariig]

@lguohan please merge if no further concerns

[nazariig]

@lguohan kindly reminder - please have a look