Re: [hatari-devel] Disk driver memory access checks

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Le 13/10/2018 à 18:39, Uwe Seimet a écrit :
Also consider this: If I try to read data from IDE/ACSI/SCSI, where the device
is mapped to a device file /dev/sd*, to a ROM area, a real Atari will crash. At
least I assume so, because I'm not aware of any hard disk driver that would
prevent this and just abort the transfer.

Now assume that the same device file is accessed not via /dev/sd* but by
nf_scsidrv. In this case the actual device is the same, but the device file
is /dev/sg*. For the caller of the SCSI Driver (or the hard disk/CD-ROM
etc. driver) this is transparent, i.e. the caller does not know how the
device is mapped. Would you expect the same to happen in both cases when
trying to load data into ROM, or would you expect a different behavior?


if transfer is made using DMA, does DMA generate bus error when trying to write to TOS ROM or is this not handled at all and "ignored" (contrary to what would happen if the cpu try to write to ROM)

One could test this on real HW by just using xbios to read a floppy sector into ROM.


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