loaderdev

[Balanga Bar]

Is it possible to used loaderdev or uEnv.txt to boot different versions of
FreeBSD from different slices, ie /dev/da0s2 /dev/da0s3 etc.

I'm trying to compare different builds and having them all on one USB stick
would be convenient.

On Sat, Apr 20, 2019 at 9:22 AM Balanga Bar <balanga.bar at gmail.com> wrote:

> I wondered about FreeBSD being able to access uBoot environment
> variables... fw_printenv and fw_setenv are available on Linux, so are
> equivalent programs available on FreeBSD?
>
> On Thu, Apr 18, 2019 at 3:25 PM Ian Lepore <ian at freebsd.org> wrote:
>
>> On Thu, 2019-04-18 at 09:30 +0100, Balanga Bar wrote:
>> > How does uBoot know how to load ubldr? Is this specific to a particular
>> > version of uBoot? I'm using a customised uBoot which lets me boot
>> OpenWrt,
>> > Debian, Arch Linux or FreeBSD depending on the contents of a USB stick.
>> >
>> > Currently I have a /boot/uEnv.txt file on a FAT partition which includes
>> >
>> > bootfile=ubldr
>> >
>> > Will I no longer need a FAT partition?
>> >
>> > If loaderdev is set to disk, then where is ubldr loaded from since,
>> AFAIK,
>> > uBoot can only read FAT or EXT3 partitions?
>> >
>>
>> The convention for freebsd mailing lists is to bottom-post replies,
>> mixed top and bottom posting makes for unreadable threads.
>>
>> The loaderdev variable is not used by uboot at all, it is read from the
>> uboot environment by ubldr.  Basically, loaderdev just gives you a way
>> to control where ubldr finds the kernel by setting a uboot env var
>> (interactively or via uenv.txt).
>>
>> You arrange to have uboot load ubldr in whatever way you're currently
>> doing, so you will still need a FAT partition, because uboot can't read
>> UFS filesystems.
>>
>> -- Ian
>>
>>