Ampro’s CoreModule 400 support has logic on the board
that makes a Type I or II flash disk appear as an IDE
drive. QNX has no idea it’s a flash device. Even the
BIOS doesn’t seem to know it’s a flash device.
What are the implications of this? Excessive updating
of the time of last reference? Recovery problems?
What happens on power fail? Who cleans up the flash
data structures?
It seems to work fine; I put a SanDisk 256MB flash
card in the slot and installed QNX 6.2.1 NC into
a 128MB partition.
John Nagle
Team Overbot
John Nagle <nagle@downside.com> wrote:
Ampro’s CoreModule 400 support has logic on the board
that makes a Type I or II flash disk appear as an IDE
drive. QNX has no idea it’s a flash device. Even the
BIOS doesn’t seem to know it’s a flash device.
Yup, the firmware on the device “pretends” to be IDE.
What are the implications of this? Excessive updating
of the time of last reference?
Could happen – you probably want to specify the “noatime”
fsys option to devb-eide.
Recovery problems?
What happens on power fail? Who cleans up the flash
data structures?
Don’t have a power fail. 
Yes, “ondisk” flash could get corrupted by a power fail. With these
devices, you generally want to get as smooth a power-down as possible.
Some companies sell different levels/qualities of flash drive, which
handle powerfail better (maintain capacitor/batter to finish all writes
cleanly or something).
It seems to work fine; I put a SanDisk 256MB flash
card in the slot and installed QNX 6.2.1 NC into
a 128MB partition.
I would not suggest using it for development – it will have a limitted
lifecycle, though it may use a distributed enough erase implementation
that it is still quite long. (And, it will probably be slower than
disk as well.)
-David
QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.
David Gibbs wrote:
Recovery problems?
What happens on power fail? Who cleans up the flash
data structures?
Don’t have a power fail. >
Yes, “ondisk” flash could get corrupted by a power fail. With these
devices, you generally want to get as smooth a power-down as possible.
Some companies sell different levels/qualities of flash drive, which
handle powerfail better (maintain capacitor/batter to finish all writes
cleanly or something).
Uh oh. That’s not a good answer for industrial applications.
John Nagle