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331722 |
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29-Mar-2018 |
eadler |
Revert r330897:
This was intended to be a non-functional change. It wasn't. The commit message was thus wrong. In addition it broke arm, and merged crypto related code.
Revert with prejudice.
This revert skips files touched in r316370 since that commit was since MFCed. This revert also skips files that require $FreeBSD$ property changes.
Thank you to those who helped me get out of this mess including but not limited to gonzo, kevans, rgrimes.
Requested by: gjb (re)
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239675 |
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25-Aug-2012 |
rwatson |
Add a device driver for the Altera University Program SD Card IP Core, which can be synthesised in Altera FPGAs. An altera_sdcardc device probes during the boot, and /dev/altera_sdcard devices come and go as inserted and removed. The device driver attaches directly to the Nexus, as is common for system-on-chip device drivers.
This IP core suffers a number of significant limitations, including a lack of interrupt-driven I/O -- we must implement timer-driven polling, only CSD 0 cards (up to 2G) are supported, there are serious memory access issues that require the driver to verify writes to memory-mapped buffers, undocumented alignment requirements, and erroneous error returns. The driver must therefore work quite hard, despite a fairly simple hardware-software interface. The IP core also supports at most one outstanding I/O at a time, so is not a speed demon.
However, with the above workarounds, and subject to performance problems, it works quite reliably in practice, and we can use it for read-write mounts of root file systems, etc.
Sponsored by: DARPA, AFRL
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