Incorrect size for large disks

[radishmouse]

After expanding the filesystem of a fresh install of norns220306-shield-pi3-cs4270.img onto a 256GB sd card:

• the on-screen stats show disk 37483M
• the recorder shows available 53:52:01 recording time.

But, df -h shows 224G available:

127.0.0.1 ~ $ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/root       235G  2.0G  224G   1% /
devtmpfs        420M     0  420M   0% /dev
tmpfs           452M  107M  346M  24% /dev/shm
tmpfs           181M  1.5M  180M   1% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
/dev/mmcblk0p1  253M   68M  185M  27% /boot
tmpfs            91M     0   91M   0% /run/user/1000

Similarly, on a 128GB sd card running v220306:

• on-screen stats show disk 50068M
• recorder shows 72:04:28 available recording time

However, a 64G sd card (also running v230614) shows:

• disk 52769M in the on-screen stats
• with 72:58:56 available recording time

And df -h reports 51G available:

127.0.0.1 ~ $ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/root        58G  4.4G   51G   9% /
devtmpfs        420M     0  420M   0% /dev
tmpfs           452M  107M  346M  24% /dev/shm
tmpfs           181M  1.5M  180M   1% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
/dev/mmcblk0p1  253M   68M  185M  27% /boot
tmpfs            91M     0   91M   0% /run/user/1000