README revision 1.1.2.2
1 1.1.2.2 yamt $NetBSD: README,v 1.1.2.2 2006/03/01 09:27:46 yamt Exp $ 2 1.1.2.2 yamt 3 1.1.2.2 yamt NetBSD for the Linksys NSLU2 (a.k.a. "Slug") 4 1.1.2.2 yamt ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 5 1.1.2.2 yamt 6 1.1.2.2 yamt The NSLU2 (Network Storage Link for USB 2.0 Disk Drives) is a small, cheap 7 1.1.2.2 yamt NAS device consisting of an Intel IXP420 (Xscale) CPU, a 10/100mbit Ethernet 8 1.1.2.2 yamt port, and two USB 2.0 ports. It has 32MB of SDRAM and 8MB of Flash memory, 9 1.1.2.2 yamt and runs RedBoot/Linux out of the box. 10 1.1.2.2 yamt 11 1.1.2.2 yamt It is eminently hackable. 12 1.1.2.2 yamt 13 1.1.2.2 yamt The guys over at http://www.nslu2-linux.org/ have done a good job of 14 1.1.2.2 yamt documenting just about every aspect of the hardware and original firmware. 15 1.1.2.2 yamt They also provide a custom "Unslung" Linux distribution to replace the 16 1.1.2.2 yamt original hobbled kernel/userland. 17 1.1.2.2 yamt 18 1.1.2.2 yamt Because of the amount of documentation available, and the fact that Slugs 19 1.1.2.2 yamt are available so cheaply (I paid just over UKP 50 for mine, brand new) I 20 1.1.2.2 yamt decided to buy one and port NetBSD to it. 21 1.1.2.2 yamt 22 1.1.2.2 yamt This is the result of that effort. 23 1.1.2.2 yamt 24 1.1.2.2 yamt Note: The Slug's IXP420 CPU runs in big-endian mode, so when building a 25 1.1.2.2 yamt cross toolchain you must pass "-m evbarm -a armeb" to build.sh. 26 1.1.2.2 yamt 27 1.1.2.2 yamt 28 1.1.2.2 yamt 29 1.1.2.2 yamt Current status 30 1.1.2.2 yamt ============== 31 1.1.2.2 yamt 32 1.1.2.2 yamt The following bits of Slug hardware are not (yet?) supported: 33 1.1.2.2 yamt 34 1.1.2.2 yamt - NPE Ethernet 35 1.1.2.2 yamt Someone will have to port Intel's IXP425 access library before this can 36 1.1.2.2 yamt be made to work. If that someone is you, the source code is available 37 1.1.2.2 yamt online here: 38 1.1.2.2 yamt 39 1.1.2.2 yamt http://www.intel.com/design/network/products/npfamily/ixp425.htm 40 1.1.2.2 yamt 41 1.1.2.2 yamt Look under "Tools & Software", then select "Register/Login" to download 42 1.1.2.2 yamt "Intel(R) IXP400 Software". Documentation is available in the 43 1.1.2.2 yamt "Technical Documents" section. 44 1.1.2.2 yamt 45 1.1.2.2 yamt The easiest option will be to download the non-crypto version of the 46 1.1.2.2 yamt Access Library. The crypto-enabled version requires a lot more form 47 1.1.2.2 yamt filling. The Slug's IXP420 has no crypto capabilities anyway. 48 1.1.2.2 yamt 49 1.1.2.2 yamt - Flash ROM 50 1.1.2.2 yamt You can write gzboot kernels (when support is added) to Flash using 51 1.1.2.2 yamt RedBoot, so all is not lost. 52 1.1.2.2 yamt 53 1.1.2.2 yamt - Buzzer 54 1.1.2.2 yamt In the absence of a decent API to expose the onboard buzzer to userland, 55 1.1.2.2 yamt this is not yet supported. I envisage using timer1 to generate an 56 1.1.2.2 yamt interrupt at the required rate (1-2KHz). The handler will toggle the 57 1.1.2.2 yamt buzzer GPIO pin. Obviously timer1 will be configured only when necessary 58 1.1.2.2 yamt as a 1-2KHz interrupt rate will sap a fair bit of CPU horsepower. 59 1.1.2.2 yamt 60 1.1.2.2 yamt Everything else is fully supported, including the power/reset buttons and 61 1.1.2.2 yamt disk activity/status LEDs. 62 1.1.2.2 yamt 63 1.1.2.2 yamt Non-hardware items on the TODO list include: 64 1.1.2.2 yamt 65 1.1.2.2 yamt - gzboot support. 66 1.1.2.2 yamt This needs to emulate a "vmlinuz" compressed Linux kernel image so that 67 1.1.2.2 yamt RedBoot will invoke the kernel from Flash at power-up. 68 1.1.2.2 yamt 69 1.1.2.2 yamt - Move the kernel link address closer to the start of SDRAM. We waste a 70 1.1.2.2 yamt little under 2MB with the current setup. 71 1.1.2.2 yamt 72 1.1.2.2 yamt - The clock runs slow. In ixp425_timer.c, COUNTS_PER_SEC is defined as 73 1.1.2.2 yamt 66666600 instead of 66666667. This, together with rounding errors, is 74 1.1.2.2 yamt almost certainly the cause. 75 1.1.2.2 yamt 76 1.1.2.2 yamt 77 1.1.2.2 yamt 78 1.1.2.2 yamt Getting NetBSD onto the NSLU2 79 1.1.2.2 yamt ============================= 80 1.1.2.2 yamt 81 1.1.2.2 yamt Thanks to the efforts of the guys over at www.nslu2-linux.org, hacking the 82 1.1.2.2 yamt Slug is a pretty easy proposition, but some soldering skills are essential. 83 1.1.2.2 yamt For a first-time install of NetBSD (at least until someone comes up with a 84 1.1.2.2 yamt nice easy binary install image) you will almost certainly require access to 85 1.1.2.2 yamt the serial console. This means firing up your trusty soldering iron and 86 1.1.2.2 yamt hooking up a MAX3232 chip to your Slug. While your soldering iron is hot, 87 1.1.2.2 yamt you should seriously consider de-restricting your Slug's CPU core clock 88 1.1.2.2 yamt speed (133MHz stock, 266MHz de-restricted) by removing a single surface- 89 1.1.2.2 yamt mount resistor. Full instructions for both the these mods are on the above 90 1.1.2.2 yamt website. 91 1.1.2.2 yamt 92 1.1.2.2 yamt Once you have console access you can interrupt RedBoot's auto-boot process 93 1.1.2.2 yamt using CTRL-C. You are now in a position to download a NetBSD kernel into 94 1.1.2.2 yamt SDRAM. 95 1.1.2.2 yamt 96 1.1.2.2 yamt You will have to configure a TFTP server on a machine hooked up to the same 97 1.1.2.2 yamt Ethernet segment as the Slug. This machine's Ethernet interface must also 98 1.1.2.2 yamt be configured to have an address in the 192.168.0.0/24 subnet since the 99 1.1.2.2 yamt Slug's Ethernet *always* defaults to 192.168.0.1 when running RedBoot. 100 1.1.2.2 yamt There seems to be no way to alter this, so the best course of action will 101 1.1.2.2 yamt probably be to set up an alias on the server's interface. 192.168.0.2 is 102 1.1.2.2 yamt a good choice. 103 1.1.2.2 yamt 104 1.1.2.2 yamt Assuming you've done all that and have dropped a suitable kernel image 105 1.1.2.2 yamt into the TFTP directory, the following commands will load and run the 106 1.1.2.2 yamt kernel. 107 1.1.2.2 yamt 108 1.1.2.2 yamt redboot> ip_address -h 192.168.0.2 109 1.1.2.2 yamt redboot> load -r -b 0x200000 netbsd.bin 110 1.1.2.2 yamt redboot> go 111 1.1.2.2 yamt 112 1.1.2.2 yamt At this point your only real option is to mount the root filesystem from 113 1.1.2.2 yamt a USB disk device as the onboard Ethernet is not (yet?) supported. However, 114 1.1.2.2 yamt there's nothing to stop you using a USB-Ethernet interface... 115 1.1.2.2 yamt 116 1.1.2.2 yamt Note that the kernel will always report the CPU core clock speed as 266MHz 117 1.1.2.2 yamt even if your Slug's CPU clock is running at a stock 133MHz. 118 1.1.2.2 yamt 119 1.1.2.2 yamt 120 1.1.2.2 yamt 121 1.1.2.2 yamt Burning a NetBSD kernel into Flash 122 1.1.2.2 yamt ================================== 123 1.1.2.2 yamt 124 1.1.2.2 yamt TBD (waiting for gzboot support). 125 1.1.2.2 yamt 126
Indexes created Sat Nov 01 21:09:44 GMT 2025