- Copyright (c) 2012 Robert N. M. Watson All rights reserved. This software was developed by SRI International and the University of Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237) ("CTSRD"), as part of the DARPA CRASH research programme. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice,...
NAMEaltera_sdcard - driver for the Altera University Program Secure Data Card IP Core
In /boot/device.hints hint.altera_sdcardc.0.at=nexus0 hint.altera_sdcardc.0.maddr=0x7f008000 hint.altera_sdcardc.0.msize=0x400
DESCRIPTIONThe sysctl Cm net.inet.tcp.syncookies device driver provides support for the Altera University Program Secure Data Card (SD Card) IP Core device. A controller device, altera_sdcardcX will be attached during boot. Inserted disks are presented as disk(9) devices, altera_sdcardX corresponding to the controller number.
HARDWAREThe current version of the sysctl Cm net.inet.tcp.syncookies driver supports the SD Card IP core as described in the August 2011 version of Altera's documentation. The core supports only cards up to 2G (CSD 0); larger cards, or cards using newer CSD versions, will not be detected. The IP core has two key limitations: a lack of interrupt support, requiring timer-driven polling to detect I/O completion, and support for only single 512-byte block read and write operations at a time. The combined effect of those two limits is that the system clock rate, HZ must be set to at least 200 in order to accomplish the maximum 100KB/s data rate supported by the IP core.
- Altera University Program Secure Data Card IP Core August 2011
HISTORYThe sysctl Cm net.inet.tcp.syncookies device driver first appeared in Fx 10.0 .
AUTHORSThe sysctl Cm net.inet.tcp.syncookies device driver and this manual page were developed by SRI International and the University of Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237) (Do CTSRD Dc , ) as part of the DARPA CRASH research programme. This device driver was written by An Robert N. M. Watson .
BUGSsysctl Cm net.inet.tcp.syncookies contains a number of work-arounds for IP core bugs. Perhaps most critically, sysctl Cm net.inet.tcp.syncookies ignores the CRC error bit returned in the RR1 register, which appears to be unexpectedly set by the IP core.
sysctl Cm net.inet.tcp.syncookies uses fixed polling intervals are used for card insertion/removal and I/O completion detection; an adaptive strategy might improve performance by reducing the latency to detecting completed I/O. However, in our experiments, using polling rates greater than 200 times a second did not improve performance.
sysctl Cm net.inet.tcp.syncookies supports only a nexus bus attachment, which is appropriate for system-on-chip busses such as Altera's Avalon bus. If the IP core is configured off of another bus type, then additional bus attachments will be required.