Re: Partition layout of ARM SD card images

> Am 10.07.2022 um 18:44 schrieb Mark Millard <marklmi@yahoo.com>:
> 
> On 2022-Jul-10, at 14:02, Dr. Rolf Jansen <freebsd-rj@cyclaero.com> wrote:
> 
>> Well, I thought the arm64-RPi one is a general purpose layout becase the armv7 one is identical:
> 
> So far as I'm aware, the RPi*'s are unique in having all the
> content in a file system instead of having some content outside
> any file system. This tends to make them generally unusual in
> various respects as far a Small Board Computers go.
> 
> It is also why I can normally add a RPi* dual-boot configuration
> adjustment to a configuration for another Small Board Computer
> (such as the Rock64): no conflict is generated by the 2 U-Boots
> or other such.
> 
>> mdconfig -a -u 0 -t vnode -f diskimg/FreeBSD-13.1-RELEASE-arm-armv7-GENERICSD.img
>> gpart show md0 md0s2
>> 
>>  =>     63  6291393  md0  MBR  (3.0G)
>>         63     2016       - free -  (1.0M)
>>       2079   102312    1  fat32lba  [active]  (50M)
>>     104391  6187041    2  freebsd  (3.0G)
>>    6291432       24       - free -  (12K)
>> 
>>  =>      0  6187041  md0s2  BSD  (3.0G)
>>          0       57         - free -  (29K)
>>         57  6186880      1  freebsd-ufs  (2.9G)
>>    6186937      104         - free -  (52K)
>> 
>> Must be something historical.
> 
> Just for reference for 32-bit (hard float) raspios:
> 
> https://downloads.raspberrypi.org/raspios_lite_armhf/images/raspios_lite_armhf-2022-04-07/2022-04-04-raspios-bullseye-armhf-lite.img.xz
> 
> # mdconfig -a -u 2 -t vnode -f 2022-04-04-raspios-bullseye-armhf-lite.img 
> # gpart show md2
> =>     63  3940289  md2  MBR  (1.9G)
>       63     8129       - free -  (4.0M)
>     8192   524288    1  fat32lba  (256M)
>   532480  3407872    2  linux-data  (1.6G)
> 
> So the same use of 8192 and 256M these days for 32-bit
> raspios.

2079 and 8192 are starting blocks of the fat32 partition, and 2079 vs. 8192 is the difference between non-aligned and aligned. My concern is not the size but whether the partitions are aligned.

BTW, I use FreeBSD-13.1-RELEASE-arm-armv7-GENERICSD.img for the BeagleBone Black's and for these I also changed the partitions so the fat32 becomes 4k aligned.