Paritioning scheme on MBR disk doubts

[Ralf Mardorf]

On Fri, 27 Aug 2021 19:02:08 +0200, Ralf Mardorf wrote:
>On Fri, 27 Aug 2021 16:02:35 +0200, Javier wrote:
>>Anyway, all this makes me ask now... does FreeBSD have any kind of
>>limitation I could suffer in the way the MBR implementation is
>>setup/programmed?  
>
>I'm not aware of limitation you need to worry about in real world
>scenarios, other than...
>
>(I'm mainly a Linux multi-boot user. I migrated from GRUB legacy to
>GRUB 2 to syslinux. However, in the past I also chainloaded FreeBSD.
>All my old internal HDDs were, as well as my new internal SSDs and
>external HDDs are <= 2 TiB MBR drives only.)
>
>...the other day I read something scary. It's not related to an
>operating system, bootloader or partitioning tool. It's a hardware
>issue.
>
>Some mobo vendors have dropped legacy BIOS support, thus they dropped
>booting an operating system from MBR formatted devices. It's required
>to migrate from MBR to GPT for those drives, if there is the need to
>replace a mobo, by another one that doesn't provide a legacy BIOS
>option. IIRC the related Unified Extensible Firmware Interface term for
>booting MBR partitions is "CSM support".

Off-topic:

From a Linux user point of view using MBR is important, to clearly
express, that PID 1 is the init process and not at all related to a
bootloader. Keyword "systemd-boot" ... can't be used with MBR.