[syslinux] [PATCH] : Adding dlabel option to chain.c32
Ady Ady
ady-sf at hotmail.com
Fri Jul 15 08:53:53 PDT 2016
> On 30.06.2016 19:41, Erwan Velu via Syslinux wrote:
> > The exisiting label= option offer to boot on a gpt partition that have
> > a particular label.
> > The existing guuid= option offer to boot on a disk or partition with a
> > particular label.
> >
> > This new option offer to boot the disk that have a partition which
> > have a given label.
> > The label is so just a way to detect a disk to boot.
> >
> > A typical use is for making an intelligent localboot like :
> >
> > label localboot
> > com32 chain.c32
> > append dlabel=datapartition
> >
> > This allow booting on a disk that sports a least one partition
> > labelled "datapartition".
> >
> > You can consider dlabel= doing almost what mbr= does but by inspecting
> > the gpt partitions label.
> >
> >
> > Please find below the commit :
> > https://github.com/ErwanAliasr1/syslinux/commit/ebf8cbfb8cef49517aa36b4a79998b4332289489
> >
>
>
> # gdisk -l /dev/vda
> ...
> Partition table scan:
> MBR: protective
> BSD: not present
> APM: not present
> GPT: present
>
> Found valid GPT with protective MBR; using GPT.
> ...
> Number Start (sector) End (sector) Size Code Name
> 1 2048 411647 200.0 MiB EF00 EFI System Partition
> 2 411648 1435647 500.0 MiB 8300 BOOT System Partition
> 3 1435648 22646783 10.1 GiB 8300 ROOT System Partition
> 4 22646784 25163775 1.2 GiB 8200 SWAP System Partition
>
>
> # fdisk -l /dev/vda
> ...
> Disklabel type: gpt
> ...
> Device Start End Sectors Size Type
> /dev/vda1 2048 411647 409600 200M EFI System
> /dev/vda2 411648 1435647 1024000 500M Linux filesystem
> /dev/vda3 1435648 22646783 21211136 10.1G Linux filesystem
> /dev/vda4 22646784 25163775 2516992 1.2G Linux swap
>
>
> # fatlabel /dev/vda1
> labelefi
>
> # e2label /dev/vda2
> labelboot
>
> # e2label /dev/vda3
> labelroot
>
> # swaplabel /dev/vda4
> LABEL: labelswap
> ...
>
>
> Filesystem *label* and *label* of a swap area
> distinguish from
> GPT *name* of a partition
>
_If_ I understand Erwan's patch correctly, we are talking about the GPT Partition Name, not the
filesystem's label (but I could be wrong).
>
> Therefore -if- you are referring to a GPT partition *name*,
> simple *name* as append option - for GPT partition *name* selection, should suffice
> i.e.
> ...
> append name=gptpartitionname
Not exactly. We are distinguishing between the GPT Partition Name being used just to select the
next device (for example, your "ROOT System Partition"), and the (Protective) MBR we are jumping
to, in BIOS / CSM mode.
In my prior email I suggested "diskbypartname" with relevant explanations (see
http://www.syslinux.org/archives/2016-July/025305.html ).
Tests and feedback are appreciated.
Regards,
Ady.
> _______________________________________________
> Syslinux mailing list
> Submissions to Syslinux at zytor.com
> Unsubscribe or set options at:
> http://www.zytor.com/mailman/listinfo/syslinux
More information about the Syslinux
mailing list