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| Release Notes for Linux on Intel's IXP4xx Network Processor |
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| Maintained by Deepak Saxena <dsaxena@plexity.net> |
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| 1. Overview |
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| Intel's IXP4xx network processor is a highly integrated SOC that |
| is targeted for network applications, though it has become popular |
| in industrial control and other areas due to low cost and power |
| consumption. The IXP4xx family currently consists of several processors |
| that support different network offload functions such as encryption, |
| routing, firewalling, etc. The IXP46x family is an updated version which |
| supports faster speeds, new memory and flash configurations, and more |
| integration such as an on-chip I2C controller. |
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| For more information on the various versions of the CPU, see: |
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| http://developer.intel.com/design/network/products/npfamily/ixp4xx.htm |
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| Intel also made the IXCP1100 CPU for sometime which is an IXP4xx |
| stripped of much of the network intelligence. |
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| 2. Linux Support |
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| Linux currently supports the following features on the IXP4xx chips: |
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| - Dual serial ports |
| - PCI interface |
| - Flash access (MTD/JFFS) |
| - I2C through GPIO on IXP42x |
| - GPIO for input/output/interrupts |
| See arch/arm/mach-ixp4xx/include/mach/platform.h for access functions. |
| - Timers (watchdog, OS) |
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| The following components of the chips are not supported by Linux and |
| require the use of Intel's proprietary CSR software: |
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| - USB device interface |
| - Network interfaces (HSS, Utopia, NPEs, etc) |
| - Network offload functionality |
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| If you need to use any of the above, you need to download Intel's |
| software from: |
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| http://developer.intel.com/design/network/products/npfamily/ixp425.htm |
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| DO NOT POST QUESTIONS TO THE LINUX MAILING LISTS REGARDING THE PROPRIETARY |
| SOFTWARE. |
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| There are several websites that provide directions/pointers on using |
| Intel's software: |
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| http://sourceforge.net/projects/ixp4xx-osdg/ |
| Open Source Developer's Guide for using uClinux and the Intel libraries |
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| http://gatewaymaker.sourceforge.net/ |
| Simple one page summary of building a gateway using an IXP425 and Linux |
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| http://ixp425.sourceforge.net/ |
| ATM device driver for IXP425 that relies on Intel's libraries |
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| 3. Known Issues/Limitations |
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| 3a. Limited inbound PCI window |
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| The IXP4xx family allows for up to 256MB of memory but the PCI interface |
| can only expose 64MB of that memory to the PCI bus. This means that if |
| you are running with > 64MB, all PCI buffers outside of the accessible |
| range will be bounced using the routines in arch/arm/common/dmabounce.c. |
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| 3b. Limited outbound PCI window |
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| IXP4xx provides two methods of accessing PCI memory space: |
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| 1) A direct mapped window from 0x48000000 to 0x4bffffff (64MB). |
| To access PCI via this space, we simply ioremap() the BAR |
| into the kernel and we can use the standard read[bwl]/write[bwl] |
| macros. This is the preffered method due to speed but it |
| limits the system to just 64MB of PCI memory. This can be |
| problamatic if using video cards and other memory-heavy devices. |
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| 2) If > 64MB of memory space is required, the IXP4xx can be |
| configured to use indirect registers to access PCI This allows |
| for up to 128MB (0x48000000 to 0x4fffffff) of memory on the bus. |
| The disadvantage of this is that every PCI access requires |
| three local register accesses plus a spinlock, but in some |
| cases the performance hit is acceptable. In addition, you cannot |
| mmap() PCI devices in this case due to the indirect nature |
| of the PCI window. |
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| By default, the direct method is used for performance reasons. If |
| you need more PCI memory, enable the IXP4XX_INDIRECT_PCI config option. |
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| 3c. GPIO as Interrupts |
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| Currently the code only handles level-sensitive GPIO interrupts |
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| 4. Supported platforms |
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| ADI Engineering Coyote Gateway Reference Platform |
| http://www.adiengineering.com/productsCoyote.html |
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| The ADI Coyote platform is reference design for those building |
| small residential/office gateways. One NPE is connected to a 10/100 |
| interface, one to 4-port 10/100 switch, and the third to and ADSL |
| interface. In addition, it also supports to POTs interfaces connected |
| via SLICs. Note that those are not supported by Linux ATM. Finally, |
| the platform has two mini-PCI slots used for 802.11[bga] cards. |
| Finally, there is an IDE port hanging off the expansion bus. |
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| Gateworks Avila Network Platform |
| http://www.gateworks.com/support/overview.php |
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| The Avila platform is basically and IXDP425 with the 4 PCI slots |
| replaced with mini-PCI slots and a CF IDE interface hanging off |
| the expansion bus. |
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| Intel IXDP425 Development Platform |
| http://www.intel.com/design/network/products/npfamily/ixdpg425.htm |
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| This is Intel's standard reference platform for the IXDP425 and is |
| also known as the Richfield board. It contains 4 PCI slots, 16MB |
| of flash, two 10/100 ports and one ADSL port. |
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| Intel IXDP465 Development Platform |
| http://www.intel.com/design/network/products/npfamily/ixdp465.htm |
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| This is basically an IXDP425 with an IXP465 and 32M of flash instead |
| of just 16. |
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| Intel IXDPG425 Development Platform |
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| This is basically and ADI Coyote board with a NEC EHCI controller |
| added. One issue with this board is that the mini-PCI slots only |
| have the 3.3v line connected, so you can't use a PCI to mini-PCI |
| adapter with an E100 card. So to NFS root you need to use either |
| the CSR or a WiFi card and a ramdisk that BOOTPs and then does |
| a pivot_root to NFS. |
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| Motorola PrPMC1100 Processor Mezanine Card |
| http://www.fountainsys.com |
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| The PrPMC1100 is based on the IXCP1100 and is meant to plug into |
| and IXP2400/2800 system to act as the system controller. It simply |
| contains a CPU and 16MB of flash on the board and needs to be |
| plugged into a carrier board to function. Currently Linux only |
| supports the Motorola PrPMC carrier board for this platform. |
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| 5. TODO LIST |
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| - Add support for Coyote IDE |
| - Add support for edge-based GPIO interrupts |
| - Add support for CF IDE on expansion bus |
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| 6. Thanks |
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| The IXP4xx work has been funded by Intel Corp. and MontaVista Software, Inc. |
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| The following people have contributed patches/comments/etc: |
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| Lennerty Buytenhek |
| Lutz Jaenicke |
| Justin Mayfield |
| Robert E. Ranslam |
| [I know I've forgotten others, please email me to be added] |
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| Last Update: 01/04/2005 |