At this time there are no plans to explicitly support 4K block sectors
directly in the kernel. The kernel itself does not support any block
devices directly, it relies on the BIOS interface, though additional
drives or support may be added through device drivers.
I would like to review the FreeDOS utilities to ensure we are
optimally using 4K sectored drives when emulation is being used (i.e.
4K aligned read/writes where feasible), but can not provide any
specific timelines as I still need to figure out how 4K sectors effect
the various utilities and how best to handle them.
In your specific case, given that USB support is not directly in the
kernel I would need more information about which USB stack you are
using to access the drives. Assuming the driver is providing BIOS LBA
based extended read/write functions and get device parameters reports
sector size of 4K then it may be feasible to update the kernel to
support such a device - at least via a kernel provided translation
(512 byte emulation) - for data purposes. The boot code is currently
limited to 512 byte sectored devices, but actually 4K sized sectors
could be supported with a different boot sector if the computer's BIOS
would support booting such a device. I would need to research the
code and other issues before providing a good response. Its been a
while since I read the cluster to sector code, I believe since DOS
works at cluster level primarily, accessing 4KB drives is feasible
without breaking too much compatibility assuming minimal of 4KB
cluster size; though for many DOS programs 512 byte access is expected
and would either need to be provided via some emulation or simply
indicate such programs are not supported with 4KB sectored drives.
Note: I am not sure any current drives/BIOS combinations will actually
provide correct sector size of drive.
Sorry it has taken a while to respond, I follow the list fairly often
but not on a computer and I find it tedious to to reply on a tiny
touch screen. I also get automatically emailed for most sourceforge
bug issues though I only respond when I have something useful to add.
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