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EDR kernel and USB drive recognition

Hi. Should Svardos + EDR kernel recognize USB flash drives that were inserted before booting? I used this known trick all the time with an earlier, FreeDOS-kernel based version of Svar. Currently, however, the 2025042 build + EDR doesn't seem to recognize any of my FAT32-formatted USB keys. Haven't tested any DOS USB drivers yet. It's also a different computer than before (Thinkpad T42), so it might possibly be a hardware/port issue. I doubt that, though, since I could boot the Svar installation USB just fine. Thanks for any help, Mart
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Hi. I am not aware of a general problem regarding USB sticks and the EDR kernel. It mainly depends on the BIOS exposing the USB drive as hard disk via its INT13 routines.
> It's also a different computer than before (Thinkpad T42), so it might possibly be a hardware/port issue. I doubt that, though, since I could boot the Svar installation USB just fine.
To rule out the PC BIOS, can you please replace the EDR kernel.sys with the FreeDOS kernel.sys, either by manually overwriting it or by uninstalling the KERNLEDR package and installing the KERNLFD package? The two kernels are now more or less interchangable. And please tell us if that makes any difference... Booting from USB might indeed make a difference! The BIOS might expose the USB drive differently when booting from it! Bernd
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You may also use one of the older images still containing the FreeDOS kernel to compare against to EDR kernel. For example from: http://svardos.org/?p=files&dir=20240726
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This appeared to be a BIOS issue. Fixed with an upgrade to T42 BIOS ver 3.23 (1RETDRWW, final version), which explicitly addressed USB drive letter handling. Now everything works, FAT32 USB keys are recognized in Svar with both EDR and FD kernels, including ones with multiple partitions. Great! As per Bernd's suggestion (many thanks!), I also tried switching to FD kernel etc prior to upgrading the BIOS, but that didn't help -- so, obviously, the issue was on the T42/BIOS side, not the OS. Thanks again! I think I'll test the DOS plug'n'play USB drivers now as well.

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