About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / arm / IXP4xx




Custom Search

Based on kernel version 3.13. Page generated on 2014-01-20 22:00 EST.

1	
2	-------------------------------------------------------------------------
3	Release Notes for Linux on Intel's IXP4xx Network Processor
4	
5	Maintained by Deepak Saxena <dsaxena@plexity.net>
6	-------------------------------------------------------------------------
7	
8	1. Overview
9	
10	Intel's IXP4xx network processor is a highly integrated SOC that
11	is targeted for network applications, though it has become popular 
12	in industrial control and other areas due to low cost and power
13	consumption. The IXP4xx family currently consists of several processors
14	that support different network offload functions such as encryption,
15	routing, firewalling, etc. The IXP46x family is an updated version which
16	supports faster speeds, new memory and flash configurations, and more
17	integration such as an on-chip I2C controller.
18	
19	For more information on the various versions of the CPU, see:
20	
21	   http://developer.intel.com/design/network/products/npfamily/ixp4xx.htm
22	
23	Intel also made the IXCP1100 CPU for sometime which is an IXP4xx 
24	stripped of much of the network intelligence.
25	
26	2. Linux Support
27	
28	Linux currently supports the following features on the IXP4xx chips:
29	
30	- Dual serial ports
31	- PCI interface
32	- Flash access (MTD/JFFS)
33	- I2C through GPIO on IXP42x
34	- GPIO for input/output/interrupts 
35	  See arch/arm/mach-ixp4xx/include/mach/platform.h for access functions.
36	- Timers (watchdog, OS)
37	
38	The following components of the chips are not supported by Linux and
39	require the use of Intel's proprietary CSR software:
40	
41	- USB device interface
42	- Network interfaces (HSS, Utopia, NPEs, etc)
43	- Network offload functionality
44	
45	If you need to use any of the above, you need to download Intel's
46	software from:
47	
48	   http://developer.intel.com/design/network/products/npfamily/ixp425.htm    
49	
50	DO NOT POST QUESTIONS TO THE LINUX MAILING LISTS REGARDING THE PROPRIETARY
51	SOFTWARE.
52	
53	There are several websites that provide directions/pointers on using
54	Intel's software:
55	
56	   http://sourceforge.net/projects/ixp4xx-osdg/
57	   Open Source Developer's Guide for using uClinux and the Intel libraries 
58	
59	http://gatewaymaker.sourceforge.net/ 
60	   Simple one page summary of building a gateway using an IXP425 and Linux
61	
62	http://ixp425.sourceforge.net/
63	   ATM device driver for IXP425 that relies on Intel's libraries
64	
65	3. Known Issues/Limitations
66	
67	3a. Limited inbound PCI window
68	
69	The IXP4xx family allows for up to 256MB of memory but the PCI interface
70	can only expose 64MB of that memory to the PCI bus. This means that if
71	you are running with > 64MB, all PCI buffers outside of the accessible
72	range will be bounced using the routines in arch/arm/common/dmabounce.c.
73	   
74	3b. Limited outbound PCI window
75	
76	IXP4xx provides two methods of accessing PCI memory space:
77	
78	1) A direct mapped window from 0x48000000 to 0x4bffffff (64MB).
79	   To access PCI via this space, we simply ioremap() the BAR
80	   into the kernel and we can use the standard read[bwl]/write[bwl]
81	   macros. This is the preffered method due to speed but it
82	   limits the system to just 64MB of PCI memory. This can be 
83	   problamatic if using video cards and other memory-heavy devices.
84	          
85	2) If > 64MB of memory space is required, the IXP4xx can be 
86	   configured to use indirect registers to access PCI This allows 
87	   for up to 128MB (0x48000000 to 0x4fffffff) of memory on the bus. 
88	   The disadvantage of this is that every PCI access requires 
89	   three local register accesses plus a spinlock, but in some 
90	   cases the performance hit is acceptable. In addition, you cannot 
91	   mmap() PCI devices in this case due to the indirect nature
92	   of the PCI window.
93	
94	By default, the direct method is used for performance reasons. If
95	you need more PCI memory, enable the IXP4XX_INDIRECT_PCI config option.
96	
97	3c. GPIO as Interrupts
98	
99	Currently the code only handles level-sensitive GPIO interrupts 
100	
101	4. Supported platforms
102	
103	ADI Engineering Coyote Gateway Reference Platform
104	http://www.adiengineering.com/productsCoyote.html
105	
106	   The ADI Coyote platform is reference design for those building 
107	   small residential/office gateways. One NPE is connected to a 10/100
108	   interface, one to 4-port 10/100 switch, and the third to and ADSL
109	   interface. In addition, it also supports to POTs interfaces connected
110	   via SLICs. Note that those are not supported by Linux ATM. Finally,
111	   the platform has two mini-PCI slots used for 802.11[bga] cards.
112	   Finally, there is an IDE port hanging off the expansion bus.
113	
114	Gateworks Avila Network Platform
115	http://www.gateworks.com/support/overview.php
116	
117	   The Avila platform is basically and IXDP425 with the 4 PCI slots
118	   replaced with mini-PCI slots and a CF IDE interface hanging off
119	   the expansion bus.
120	
121	Intel IXDP425 Development Platform
122	http://www.intel.com/design/network/products/npfamily/ixdpg425.htm  
123	
124	   This is Intel's standard reference platform for the IXDP425 and is 
125	   also known as the Richfield board. It contains 4 PCI slots, 16MB
126	   of flash, two 10/100 ports and one ADSL port.
127	
128	Intel IXDP465 Development Platform
129	http://www.intel.com/design/network/products/npfamily/ixdp465.htm
130	
131	   This is basically an IXDP425 with an IXP465 and 32M of flash instead
132	   of just 16.
133	
134	Intel IXDPG425 Development Platform
135	
136	   This is basically and ADI Coyote board with a NEC EHCI controller
137	   added. One issue with this board is that the mini-PCI slots only
138	   have the 3.3v line connected, so you can't use a PCI to mini-PCI
139	   adapter with an E100 card. So to NFS root you need to use either
140	   the CSR or a WiFi card and a ramdisk that BOOTPs and then does
141	   a pivot_root to NFS.
142	
143	Motorola PrPMC1100 Processor Mezanine Card
144	http://www.fountainsys.com
145	
146	   The PrPMC1100 is based on the IXCP1100 and is meant to plug into
147	   and IXP2400/2800 system to act as the system controller. It simply
148	   contains a CPU and 16MB of flash on the board and needs to be
149	   plugged into a carrier board to function. Currently Linux only
150	   supports the Motorola PrPMC carrier board for this platform.
151	
152	5. TODO LIST
153	
154	- Add support for Coyote IDE
155	- Add support for edge-based GPIO interrupts
156	- Add support for CF IDE on expansion bus
157	
158	6. Thanks
159	
160	The IXP4xx work has been funded by Intel Corp. and MontaVista Software, Inc.
161	
162	The following people have contributed patches/comments/etc:
163	
164	Lennerty Buytenhek
165	Lutz Jaenicke
166	Justin Mayfield
167	Robert E. Ranslam
168	[I know I've forgotten others, please email me to be added] 
169	
170	-------------------------------------------------------------------------
171	
172	Last Update: 01/04/2005
Hide Line Numbers
About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Information is copyright its respective author. All material is available from the Linux Kernel Source distributed under a GPL License. This page is provided as a free service by mjmwired.net.