Although FreeBSD/mips has been committed to the tree, a few stragglers haven't been pushed into the tree for various reasons. Oleksandr Tymoshenko and I have been honing them down and have just published a set for review.
If you'd like to try FreeBSD/mips out, you can grab these patches from Oleksandr's directory. There's four diffs included. Please send any feedback to arch@freebsd.org.
20080729
20080726
Minor wi(4) hacking
I finally had some time, a need for wireless connectivity in the shop and found my stash of old Prism 2, 2.5 and 3 cards. I thought I'd try them out with the new vap stuff.
First, there's a new filter on the firmware revisions in the driver. Very old versions of the firmware basically don't work without a lot of coaxing and workarounds. They are no longer supported. In addition, symbol cards are fairly rare and there's no readily available documentation for them, so support for them was removed as well. This filtering is a good thing, since it will keep people from using cards that are known to be broken. However, I had to fix a bug in the interrupt registration to make this work out OK (and to also stop spontaneous panics sometimes on attach if there was a lot of interrupt activity on a shared interrupt). I basically moved the interrupt registration to the end of the attach function, rather than the beginning and solved both problems.
All of these cards that I had don't have new enough firmware to support WPA. This highlights another problem: wpa_supplicant doesn't filter out WPA APs when it is looking for things to attach to, or otherwise provide a meaningful error message that would tell the user the reason that WPA isn't working is that their card is too old/lame to support this new-fangled stuff....
I wound up solving my problem with an atheros card that just worked, once I found them...
First, there's a new filter on the firmware revisions in the driver. Very old versions of the firmware basically don't work without a lot of coaxing and workarounds. They are no longer supported. In addition, symbol cards are fairly rare and there's no readily available documentation for them, so support for them was removed as well. This filtering is a good thing, since it will keep people from using cards that are known to be broken. However, I had to fix a bug in the interrupt registration to make this work out OK (and to also stop spontaneous panics sometimes on attach if there was a lot of interrupt activity on a shared interrupt). I basically moved the interrupt registration to the end of the attach function, rather than the beginning and solved both problems.
All of these cards that I had don't have new enough firmware to support WPA. This highlights another problem: wpa_supplicant doesn't filter out WPA APs when it is looking for things to attach to, or otherwise provide a meaningful error message that would tell the user the reason that WPA isn't working is that their card is too old/lame to support this new-fangled stuff....
I wound up solving my problem with an atheros card that just worked, once I found them...
20080722
Taking a break from FreeBSD core team
As has been recently announced, the FreeBSD project has selected a new core team. The project elects a new team every two years. This time, I've decided to take a break from the core team. I have a new son and I want to spend more time with him and the rest of my family.
I've had a great time on the core team. I've been serving now for 8 years. I've really enjoyed being on the core team and leading the project through some difficult times. Since my son and family are taking a lot of my time these days, I have limited time to spend on the FreeBSD project. I've done my time in the administrative side of the project for a while, and I want to spend my limited time working to make FreeBSD a better platform for the embedded platforms. I'm taking a 2 year break. We'll see how things are in 2 years...
I wish the new core team luck, although they are good people and they won't need my luck to be successful.
I've had a great time on the core team. I've been serving now for 8 years. I've really enjoyed being on the core team and leading the project through some difficult times. Since my son and family are taking a lot of my time these days, I have limited time to spend on the FreeBSD project. I've done my time in the administrative side of the project for a while, and I want to spend my limited time working to make FreeBSD a better platform for the embedded platforms. I'm taking a 2 year break. We'll see how things are in 2 years...
I wish the new core team luck, although they are good people and they won't need my luck to be successful.
20080715
Quick Guide to FreeBSD hostap for FreeBSD 8
I have a need to setup an access point. Many of the discussions on the web include all kinds of extra goodies that one normally sets up with the access point. But I just needed an access point: no dhcp, bridging, etc. Here's how I did it.
Recently, some really cool stuff when into the kernel for wireless. This is the VAP stuff, or the virtual access point code. This allows freebsd to decouple the code for doing access points, and a bunch of other stuff, from the code to drive the wireless hardware. Great in concept, and quite useful with some of the advanced wireless hardware.
However, it did change the way things were configured. The handbook is now out of date. Until it can be updated, here's what I did, with some explanations about each step.
First, I needed to create an rc.conf setup for my needs. Here's the one I came up with.
devd_enable turns on the devd(8) process. This process is responsible for dealing with the different device events in the system. This is the hook that we use for hot-plug insertions, which is how we configure the wireless devices.
wlans_ath0 is used to create the virtual interface wlan0 associated with ath0. This is how all the wireless stuff is setup now. You configure the basics with the wlan_IF=wlanX command, and set more specific stuff via the wlanX interface.
create_wlan0 gives the arguments with which to create the wlan interface. There are many that can only be created at wlanX creation time, and it happens that hostap is one of them. I'm not 100% sure that I need to bother with the 11g mode command or not here, but it seems to work.
ifconfig_wlan0 sets the device's IP address. In my example, I wanted the interface to have an IP address, but not be bridgable since I didn't have any other interfaces on the laptop I wanted to be the AP for the thing I'm doing.
hostapd_enable turns on the hostapd daemon. You won't get far without this, so we turn it on.
We've enabled a daemon, and now it is time to configure it. Here's the config file that I used for hostapd.conf:
itnerface specifies which interface to use. Duh! However, this needs to be the wlan device, not the hardware device.
hw_mode sets the hardware into 802.11g. Not sure if this is needed, but it works for me.
macaddr_acl is wide open: it allows anybody to connect. As you may have noticed, this setup is very permissive. It has nothing locked down at all. It should be the first thing you do as an experiment before proceeding on to enabling WPA or WPA2 to get a reasonable level of security.
auth_algs sets which authorization algorithms can be used. See the hostapd man page for details.
ssid sets the name of the network you are serving.
The rest can be gleaned from the manual.
Chances are this post should be updated, so if you have any suggestions on how to do that, please leave then as comments.
Recently, some really cool stuff when into the kernel for wireless. This is the VAP stuff, or the virtual access point code. This allows freebsd to decouple the code for doing access points, and a bunch of other stuff, from the code to drive the wireless hardware. Great in concept, and quite useful with some of the advanced wireless hardware.
However, it did change the way things were configured. The handbook is now out of date. Until it can be updated, here's what I did, with some explanations about each step.
First, I needed to create an rc.conf setup for my needs. Here's the one I came up with.
devd_enable=YES
ifconfig_wlan0="inet 10.0.0.1/24"
wlans_ath0="wlan0"
create_args_wlan0="wlanmode hostap mode 11g"
hostapd_enable=YES
devd_enable turns on the devd(8) process. This process is responsible for dealing with the different device events in the system. This is the hook that we use for hot-plug insertions, which is how we configure the wireless devices.
wlans_ath0 is used to create the virtual interface wlan0 associated with ath0. This is how all the wireless stuff is setup now. You configure the basics with the wlan_IF=wlanX command, and set more specific stuff via the wlanX interface.
create_wlan0 gives the arguments with which to create the wlan interface. There are many that can only be created at wlanX creation time, and it happens that hostap is one of them. I'm not 100% sure that I need to bother with the 11g mode command or not here, but it seems to work.
ifconfig_wlan0 sets the device's IP address. In my example, I wanted the interface to have an IP address, but not be bridgable since I didn't have any other interfaces on the laptop I wanted to be the AP for the thing I'm doing.
hostapd_enable turns on the hostapd daemon. You won't get far without this, so we turn it on.
We've enabled a daemon, and now it is time to configure it. Here's the config file that I used for hostapd.conf:
interface=wlan0
hw_mode=g
macaddr_acl=0
auth_algs=1
ctrl_interface=/var/run/hostapd
ctrl_interface_group=wheel
ssid=bsdimp hacking blog
itnerface specifies which interface to use. Duh! However, this needs to be the wlan device, not the hardware device.
hw_mode sets the hardware into 802.11g. Not sure if this is needed, but it works for me.
macaddr_acl is wide open: it allows anybody to connect. As you may have noticed, this setup is very permissive. It has nothing locked down at all. It should be the first thing you do as an experiment before proceeding on to enabling WPA or WPA2 to get a reasonable level of security.
auth_algs sets which authorization algorithms can be used. See the hostapd man page for details.
ssid sets the name of the network you are serving.
The rest can be gleaned from the manual.
Chances are this post should be updated, so if you have any suggestions on how to do that, please leave then as comments.
20080706
Minor mips reorg and plans for the future
In trying to bring the MIPS tree more into line with idealized FreeBSD practices, I've moved the SoC directories up one level in the hierarchy. Future changes will make it easier to define different boards, as well as stylizing these sorts of things across different CPU architectures. I need this for the Plat'Home OpenMicroServer work I've started on, so I'll use that to drive these changes.
For the curious, I've moved mips/mips32/adm5120 -> mips/adm5120, likewise with the idt, malta, and sentry5 directories. While all of these were, strictly speaking, mips32 CPUs, having them in their own subdirectory doesn't make a lot of sense. There's never going to be so many of them that having an extra layer of indirection is going to help. Also, mips32 is ambiguous. Does it mean the MIPS ISA known as MIPS32 and MIPS32r2? Does it mean that the ports are running in 32-bit mode? It wasn't clear where a 32-bit kernel for a mips64 processor would live. Also, the idt parts aren't completely mips32 compliant in a couple of minor details. Is that non-compliance enough to move them elsewhere?
The next set of changes will try to tease apart the boot loader environment from the SoC that it is running on. While many SoCs have their own bootloader, often times one may also run uboot on the same hardware. In addition, things like uboot are used in many different platforms, so duplicating that code will grow tiresome.
Once the boot loader stuff is better abstracted, the next set of problems will be how to create a system that can run on multiple different boards of the same SoC. At first, this will be statically compiled, but eventually it will be dynamic.
Another key component of this work, whose overall goal is to make it easier to add board support to FreeBSD embedded platforms, will be an overhaul of the hints system. While it can be made to work, there are some practical problems it solves poorly that are desirable to have solved better. For example, it has no good way to tie attributes or parameters to hardware. Today, one can only tie them to a driver instance, which itself can be tied to hardware.
Finally, the last planned component in this work is a simplification of creation of busses with attributes and fixed or semi-fixed children. You can't have variants of hints loaded today that say "If I'm running on a AT91RM9200, use this set, but if I'm runnning on an AT91SAM9620 use this other set of hints" to enumerate the busses. This makes it hard to achieve the dynamic selection of boot code to run needed to allow kernels to boot on a variety of boards.
Most of this is low-level code janitor stuff. However, it is code janitor stuff that's needed and will be important to FreeBSD's success in the future.
For the curious, I've moved mips/mips32/adm5120 -> mips/adm5120, likewise with the idt, malta, and sentry5 directories. While all of these were, strictly speaking, mips32 CPUs, having them in their own subdirectory doesn't make a lot of sense. There's never going to be so many of them that having an extra layer of indirection is going to help. Also, mips32 is ambiguous. Does it mean the MIPS ISA known as MIPS32 and MIPS32r2? Does it mean that the ports are running in 32-bit mode? It wasn't clear where a 32-bit kernel for a mips64 processor would live. Also, the idt parts aren't completely mips32 compliant in a couple of minor details. Is that non-compliance enough to move them elsewhere?
The next set of changes will try to tease apart the boot loader environment from the SoC that it is running on. While many SoCs have their own bootloader, often times one may also run uboot on the same hardware. In addition, things like uboot are used in many different platforms, so duplicating that code will grow tiresome.
Once the boot loader stuff is better abstracted, the next set of problems will be how to create a system that can run on multiple different boards of the same SoC. At first, this will be statically compiled, but eventually it will be dynamic.
Another key component of this work, whose overall goal is to make it easier to add board support to FreeBSD embedded platforms, will be an overhaul of the hints system. While it can be made to work, there are some practical problems it solves poorly that are desirable to have solved better. For example, it has no good way to tie attributes or parameters to hardware. Today, one can only tie them to a driver instance, which itself can be tied to hardware.
Finally, the last planned component in this work is a simplification of creation of busses with attributes and fixed or semi-fixed children. You can't have variants of hints loaded today that say "If I'm running on a AT91RM9200, use this set, but if I'm runnning on an AT91SAM9620 use this other set of hints" to enumerate the busses. This makes it hard to achieve the dynamic selection of boot code to run needed to allow kernels to boot on a variety of boards.
Most of this is low-level code janitor stuff. However, it is code janitor stuff that's needed and will be important to FreeBSD's success in the future.
20080627
Adding a Serial Port to a D-LINK DIR-615
A while ago, I added a serial port to the D-LINK DIR-615 (HW Rev A1). Today, I'll document how I did it.
First, you'll need a level converter circuit. There are many on the network. You can find a good write up on them and links from adding a serial port to a NSLU2. I always use the Parallax USB2SER that I bought years ago. It is very reliable, and I've had several provide years of good service to me. They convert 3.3V directly into a USB serial port, which vastly simplifies power and cabling. Since that's what I used for this project, all the instructions are geared towards it.
First, you'll need to disassemble the D-LINK DIR-615. There's only two screws so this is easy. Place the D-Link with the label with the serial number face up. There are four rubber feet on the bottom of this unit. Carefully pry up the two nearest to the Ethernet ports. Remove the screws found under them. The screws are clearly visible in this photo.
Carefully remove the lid. It should pry off just above the plastic bar that runs over the ethernet ports. You'll see a green PC board. On the right hand side of the unit, you'll find a header with 4 pins labeled CON5. They are labeled VCC, TX, RX, GND. This is the serial port. In my unit, it was hidden under the internal antenna, so the photos show it moved over a bit. Note also in figure two the board says "DIR635B1" on it...
I connected these pins to a ribbon cable and ran them out to a header that my USB2SER could fit on. I connected them so that they would match up to my USB2SER which had pins in the order GND, RX, TX, RES. The last one is unconnected. TX should go to RX, RX to TX and GND to GND. I didn't connect VCC, since it wasn't needed. USB2SER gets its power from the USB port. I reconnected everything and plugged the USB2SER into my computer. I threaded the ribbon cable out through the holes in the plastic, which is what you see in the first photo. Here's everything hooked up. I didn't include a photo of the USB2SER plugged into the serial port of my laptop for obvious reasons...
I see that it has a uboot bootloader:
So that's how you add a serial port.
First, you'll need a level converter circuit. There are many on the network. You can find a good write up on them and links from adding a serial port to a NSLU2. I always use the Parallax USB2SER that I bought years ago. It is very reliable, and I've had several provide years of good service to me. They convert 3.3V directly into a USB serial port, which vastly simplifies power and cabling. Since that's what I used for this project, all the instructions are geared towards it.
First, you'll need to disassemble the D-LINK DIR-615. There's only two screws so this is easy. Place the D-Link with the label with the serial number face up. There are four rubber feet on the bottom of this unit. Carefully pry up the two nearest to the Ethernet ports. Remove the screws found under them. The screws are clearly visible in this photo.
Carefully remove the lid. It should pry off just above the plastic bar that runs over the ethernet ports. You'll see a green PC board. On the right hand side of the unit, you'll find a header with 4 pins labeled CON5. They are labeled VCC, TX, RX, GND. This is the serial port. In my unit, it was hidden under the internal antenna, so the photos show it moved over a bit. Note also in figure two the board says "DIR635B1" on it...
I connected these pins to a ribbon cable and ran them out to a header that my USB2SER could fit on. I connected them so that they would match up to my USB2SER which had pins in the order GND, RX, TX, RES. The last one is unconnected. TX should go to RX, RX to TX and GND to GND. I didn't connect VCC, since it wasn't needed. USB2SER gets its power from the USB port. I reconnected everything and plugged the USB2SER into my computer. I threaded the ribbon cable out through the holes in the plastic, which is what you see in the first photo. Here's everything hooked up. I didn't include a photo of the USB2SER plugged into the serial port of my laptop for obvious reasons...
I see that it has a uboot bootloader:
% tip ucom0
U-Boot 1.1.1 (Jan 19 2007 - 11:08:07)
CAMEO uBoot Linux Loader version: 1.3.0.0
DRAM CS[0] base 0x00000000 size 32MB
DRAM Total size 32MB
before entry mvFlashInit
Flash: flashStructGet manu 0x89 id 0x17
INTEL 28F640J3A (64 Mbit)
Size: 8 MB,Bus Width: 1, device Width: 1.
Flash base: 0xff800000,Number of Sectors: 64 Type: REGULAR.
[8192kB@ff800000] Flash: 8 MB
Addresses 20M - 0M are saved for the U-Boot usage.
Mem malloc Initialization (20M - 16M): Done
*** Warning - bad CRC, using default environment
Soc: 88F5181 B1
CPU: ARM926 (Rev 0) running @ 500Mhz
SysClock = 166Mhz , TClock = 166Mhz
USB 0: host mode
PCI 0: PCI Express Root Complex Interface
PCI 1: Conventional PCI, speed = 33000000
Net: egiga0 [PRIME]
Hit any key to stop autoboot: 0
Marvell>>
So that's how you add a serial port.
20080623
Old cards and the information gap
This time I'll explore some of the issues relating to hacking on older hardware. I'll talk about expanding the work I did for the Olicom OC-2220 to the combo OC-2232 and the problems encountered.
In a previous edition, I talked about the Olicom OC-2220 card and getting it working. It works great, and in fact, I'm using it right now to make this blog entry. However, the next card I tried didn't fare so well. This is the Olicom OC-2232, which added a 33.6k modem to the same basic design as the OC-2220. It exposes the ethernet and modem such that I had to augment the PC Card system to access. I had to be able to specify the config entry to use to configure the resources for the card. However, when I started, FreeBSD's PC Card system lacked this feature.
I was able to augment FreeBSD's PC Card system to have a feature that's been requested infrequently. The ability for the driver to select the config entry to use. Right now, all of the FreeBSD PC Card drivers have been able to use the config entry that the system guesses is the right one. However, there are some combo cards that pre-date the PCMCIA multifunction standard that need to select a config entry.
So, after adding this, it was a simple matter to get the ex driver selecting the appropriate alternate config entry for the Olicom OC-2232 that I have. This card has the Intel 82595 and a 16550 compatible 33.6k modem on it. By default, FreeBSD will happen to pick the entry that corresponds to the modem only. However, with my hacks I have been able to make it select either the ethernet side only or both. FreeBSD needs a few changes to allow it to support both of these devices at the same time, but I'll write more about that at another time.
So the card comes up, and I'm able to attach to the ex driver. But there's a problem. dhclient doesn't finish. For the OC-2220, this returns immediately, so I know that the dongle cable is good, as is the port on the hub. The OC-2232 uses the same cables, as far as I can tell, but when I try to push packets through, I never get any interrupts, so dhclient never finishes. I've not instrumented the driver to see if adding a watchdog timeout would help make this work in the absence of interrupts or not.
This leads me think about some of these old cards that I have. It is impossible to get information on them. The best I've been able to find is binary only Windows and DOS drivers for them. These drivers don't work with the current version of Windows that I have on my laptop. This makes it hard to know if the problem I'm encountering is a hardware problem or a software problem. There's no support for this card in Linux (the base kernel doesn't support and 82595 based PC Cards, and it is nearly impossible to find a driver for the few cards that used this chip that wasn't incorporated into the kernel).
So assuming the card is good, there's no source available for it. I knew there was a similar card made by Silicom called the EtherSerial card. It has a real serial port in addition to the 82595 ethernet controller on it. Searching for it was difficult. Most likely there's a trick to forcing google to tell me "Where do I find the file silpmcica-1.02b.tar.gz?" with all the variant spellings and encodings (.tgz, tar.bz2, .tbz, .tbz2, etc), but I didn't see it. Altavista used to have this feature, and I'm sure that some sharp reader will tell me how to make google do it.
I was able to find, using the internet archive, the driver for the Silicom card. Well, kinda. I was able to discover the name of the file, and also discover that the internet archive didn't cache the files that people put on their FTP sites, so when I clicked on the driver link there, it tried to grab it from Silicom's current FTP server, which isn't setup for anonymous operation.
I was able to find the datasheets for this old part, however. I was lucky this part was popular enough that the various datasheet web sites have it available. There were three variants of the part, and only the FX variant appears to have been used in the PC Card devices.
So the resort of looking for data for this card was somewhat less successful than looking for data for the Crystal Semi based card that I had. There I was able to find everything I needed, but my needs were more meager. Now, I'm left wondering: do I have bad hardware? Do I need to prod some hidden register to turn on interrupts? Do I need to disassemble the drivers that I found to make further progress? These are all good questions, and I don't have the answers to any of them. All the questions that lead me to make progress involve a lot of time doing unfun tasks that really gain me no pleasure or knowledge.
Anyway, my trip down memory lane must end soon. I have other commitments in FreeBSD that I need to return to soon. This was a fun diversion (and hardware that's easy to carry), but I'm afraid this unsatisfying dead-end will likely be where this problem sits for a while as I have some processor porting work to do for people that have donated hardware to me. I've put that off long enough based on the fun I had one night with one PC Card. I'm afraid I'm going to have to put them back on the back burner unless new information surfaces. The other hardware is more relevant, and while it is fun to misbehave sometimes with something that may not be relevant for the fun of it, there's a different kind of fun to be had when doing things with more relevant hardware, and I think it is time I got back to that kind of fun in my spare time.
In a previous edition, I talked about the Olicom OC-2220 card and getting it working. It works great, and in fact, I'm using it right now to make this blog entry. However, the next card I tried didn't fare so well. This is the Olicom OC-2232, which added a 33.6k modem to the same basic design as the OC-2220. It exposes the ethernet and modem such that I had to augment the PC Card system to access. I had to be able to specify the config entry to use to configure the resources for the card. However, when I started, FreeBSD's PC Card system lacked this feature.
I was able to augment FreeBSD's PC Card system to have a feature that's been requested infrequently. The ability for the driver to select the config entry to use. Right now, all of the FreeBSD PC Card drivers have been able to use the config entry that the system guesses is the right one. However, there are some combo cards that pre-date the PCMCIA multifunction standard that need to select a config entry.
So, after adding this, it was a simple matter to get the ex driver selecting the appropriate alternate config entry for the Olicom OC-2232 that I have. This card has the Intel 82595 and a 16550 compatible 33.6k modem on it. By default, FreeBSD will happen to pick the entry that corresponds to the modem only. However, with my hacks I have been able to make it select either the ethernet side only or both. FreeBSD needs a few changes to allow it to support both of these devices at the same time, but I'll write more about that at another time.
So the card comes up, and I'm able to attach to the ex driver. But there's a problem. dhclient doesn't finish. For the OC-2220, this returns immediately, so I know that the dongle cable is good, as is the port on the hub. The OC-2232 uses the same cables, as far as I can tell, but when I try to push packets through, I never get any interrupts, so dhclient never finishes. I've not instrumented the driver to see if adding a watchdog timeout would help make this work in the absence of interrupts or not.
This leads me think about some of these old cards that I have. It is impossible to get information on them. The best I've been able to find is binary only Windows and DOS drivers for them. These drivers don't work with the current version of Windows that I have on my laptop. This makes it hard to know if the problem I'm encountering is a hardware problem or a software problem. There's no support for this card in Linux (the base kernel doesn't support and 82595 based PC Cards, and it is nearly impossible to find a driver for the few cards that used this chip that wasn't incorporated into the kernel).
So assuming the card is good, there's no source available for it. I knew there was a similar card made by Silicom called the EtherSerial card. It has a real serial port in addition to the 82595 ethernet controller on it. Searching for it was difficult. Most likely there's a trick to forcing google to tell me "Where do I find the file silpmcica-1.02b.tar.gz?" with all the variant spellings and encodings (.tgz, tar.bz2, .tbz, .tbz2, etc), but I didn't see it. Altavista used to have this feature, and I'm sure that some sharp reader will tell me how to make google do it.
I was able to find, using the internet archive, the driver for the Silicom card. Well, kinda. I was able to discover the name of the file, and also discover that the internet archive didn't cache the files that people put on their FTP sites, so when I clicked on the driver link there, it tried to grab it from Silicom's current FTP server, which isn't setup for anonymous operation.
I was able to find the datasheets for this old part, however. I was lucky this part was popular enough that the various datasheet web sites have it available. There were three variants of the part, and only the FX variant appears to have been used in the PC Card devices.
So the resort of looking for data for this card was somewhat less successful than looking for data for the Crystal Semi based card that I had. There I was able to find everything I needed, but my needs were more meager. Now, I'm left wondering: do I have bad hardware? Do I need to prod some hidden register to turn on interrupts? Do I need to disassemble the drivers that I found to make further progress? These are all good questions, and I don't have the answers to any of them. All the questions that lead me to make progress involve a lot of time doing unfun tasks that really gain me no pleasure or knowledge.
Anyway, my trip down memory lane must end soon. I have other commitments in FreeBSD that I need to return to soon. This was a fun diversion (and hardware that's easy to carry), but I'm afraid this unsatisfying dead-end will likely be where this problem sits for a while as I have some processor porting work to do for people that have donated hardware to me. I've put that off long enough based on the fun I had one night with one PC Card. I'm afraid I'm going to have to put them back on the back burner unless new information surfaces. The other hardware is more relevant, and while it is fun to misbehave sometimes with something that may not be relevant for the fun of it, there's a different kind of fun to be had when doing things with more relevant hardware, and I think it is time I got back to that kind of fun in my spare time.
20080616
Good collection management software
Regular readers of this column know that I have a large collection of PC Cards. Some would say 'too large' and I'm not sure they'd be wrong. I was out in the garage last night looking for a specific card. I couldn't find it. I know it is there, somewhere, but don't know exactly where. Maybe I'll find it tonight when I look in a place that I remembered driving into Boulder today.
This got me to thinking: how can I manage all these cards. I need to figure out some way of recording generic information about the card. Where it lives, what dongles it needs, what driver it uses, etc. It would also be nice to know when I last tested it, how well it worked, etc. Maybe some notes about the card, like "This card has a blue label on it, and needs to have the dongle wiggled just so: .... for it to work." Oh, and it would also be nice to generate reports so that I can maintain a list of cards that I've tested and when on a web page automatically. I did this years ago, but stopped when it became too big a pita to keep current.
In the past, I've not seen anything that's good at doing all these things. I thought I'd ask my readers if they knew of anything that solves this problem? I know that there's many tools that could be used to build a solution, but many of them require a fair amount of customization to make into a workable solution. A quick google search doesn't turn up anything that's more sophisticated than a generic database. Does anybody know of something that's fairly close?
This got me to thinking: how can I manage all these cards. I need to figure out some way of recording generic information about the card. Where it lives, what dongles it needs, what driver it uses, etc. It would also be nice to know when I last tested it, how well it worked, etc. Maybe some notes about the card, like "This card has a blue label on it, and needs to have the dongle wiggled just so: .... for it to work." Oh, and it would also be nice to generate reports so that I can maintain a list of cards that I've tested and when on a web page automatically. I did this years ago, but stopped when it became too big a pita to keep current.
In the past, I've not seen anything that's good at doing all these things. I thought I'd ask my readers if they knew of anything that solves this problem? I know that there's many tools that could be used to build a solution, but many of them require a fair amount of customization to make into a workable solution. A quick google search doesn't turn up anything that's more sophisticated than a generic database. Does anybody know of something that's fairly close?
20080613
Olicom OC-2220 works
After applying John Bladwin's MPSAFE patches to the ex driver, the ex driver works with the Olicom OC-2220. If you are unfamiliar with this card, I'm not surprised. It was made in the mid 1990's. From a network perspective, it isn't that important. It is a slow 10BaseT card that doesn't seem to do full duplex.
However, from the PC Card perspective, there's some interesting things with ex. There's the Olicom OC-2232 that includes a modem. But it includes it in an interesting way that isn't quite standard. How do we pull in the serial port in this case? There's also some cards from Silicom that have a serial port bolted on as well, but in a different way. i've not seen good documentation for either of these cards, but at least there's a driver for the silicom available (or was once upon a time) for Linux. I sure hope that wasn't one of the things I lost in my disk crash...
So again, despite the age of the underlying chip, there's some interesting problems here. The trouble is that the problems are such that they can't easily be solved in an hour of hacking, so they may continue to linger....
However, from the PC Card perspective, there's some interesting things with ex. There's the Olicom OC-2232 that includes a modem. But it includes it in an interesting way that isn't quite standard. How do we pull in the serial port in this case? There's also some cards from Silicom that have a serial port bolted on as well, but in a different way. i've not seen good documentation for either of these cards, but at least there's a driver for the silicom available (or was once upon a time) for Linux. I sure hope that wasn't one of the things I lost in my disk crash...
So again, despite the age of the underlying chip, there's some interesting problems here. The trouble is that the problems are such that they can't easily be solved in an hour of hacking, so they may continue to linger....
20080612
Crystal Semiconductor Driver
Since I've been maintaining the PC Card layer in FreeBSD, I've accumulated a lot of PC Card hardware. Well over 100 different PC Card r2 (16-bit) and CardBus (32-bit) cards. Recently, Robert Watson started pushing to have all the network drivers in the tree be MPSAFE. John Bladwin posted some patches to the if_cs driver to bring it up to those standards. Since I had a soft spot in my heart for this driver for reasons I don't entirely understand, I took the IBM EtherJet PC Card that I had with me on a recent buisiness trip with the vague notion of testing out John's patches.
I discovered that the driver didn't work. It didn't work before the patches, nor after them. The breakage was minor and I likely wouldn't have noticed it except for the fact that I didn't have the Ethernet cable plugged in when I was doing the early testing. Since the breakage annoyed me, I went ahead and fixed it. I also noticed that the reading of the EEPROM was very slow, and caused me to drop characters when I inserted the card. I hate that. I discovered a number of DELAY statements in the EEPROM reading which were the cause of the problem. I thought "this is nuts" to myself, and went off to locate the datasheet for this part. After reading through it, I discovered the EEPROM busy bit that I polled in place of the hard coded 3ms DELAY. I went from having about 1.2s of DELAY and other busy waiting when I inserted the card to having on the order of 800us, a speedup of about 1500x.
This brings up a number of philosophical questions. Why did I bother with such an outdated chip? Why speed up a one time operation? Why spend any time at all on this after a busy day of meetings and crisis management?
Let's answer the last question first. I did it because I was absolutely exhausted by my meetings. While productive, and they helped to drive the problems of the project I was working on towards resolution, they were draining. By hacking on this driver I had a very safe area to make improvements. Unless I broke the build, nobody would notice the work, yet I'd have the satisfaction of a job well done. Since it is in an out-of-the way part of the kernel, I had the room to fail without throngs beating down my door. I had complete freedom to tinker and tidy as I saw fit, and doing so was very relaxing and invigorating after a long, hard day. Maybe I'm just weird, but sometimes a little bit of hacking to make something better is just what my brain needs to relax and unwind.
The reason I was spending any time at all on this was that this part made a resurgence in recent years inside embedded systems. There are several embedded designs that use this part when they don't have the ethernet on the SoC. More recent parts have all this built into the SoC, so the popularity has waned once again, but I knew some ARM boards used it, so in the back of my mind I had a justification for spending time on it based on my FreeBSD embedded hat that I wear from time to time. I was shocked to get email from someone who had one of these boards and wanted to know how to write a front end for this driver for that board within a day of my committing the cleanups. That was a nice bonus. Time will tell if he follows through, of course, but I was very amused by it.
Finally, why spend time optimizing an operation that happens only once at startup? I hate losing characters when I type. Since I didn't want to re-write the syscons keyboard driver to have a fast interrupt handler to read the keystrokes and queue them for later processing (the only thing that will interrupt a DELAY is a fast interrupt handler), I thought this was the easier path to solving my problem. I spend a lot of time at work making sure that the right priority calls are made, and it felt good to be "bad" and work on something that clearly is the wrong priority call in terms of everything else that's going on in FreeBSD.
I guess it all boils down to "I had an itch, and it felt good to scratch it." rather than any rational thought process. Sure, I justified it after the fact in many different ways, but it felt fundamentally good to just make something better for the sake of making it better and not have to worry about big picture this, or deadline that, or you broke my whatsit complaints. I had a well defined technical problem, I had to research solutions and hack a bit of code. It felt good being able to find the data I needed, fix the code, test it and see it working and passing packets again. I wish all problems that I faced in my technical life were so easy and rewarding.
Oh yea, and it turned out that I found a bug in John's patches and he was able to commit them to the tree, eliminating one more Giant Locked driver. I'm sure Robert will be happy. I'm sure there are others that would have been just as happy to have the impending removal of Giant Locked network drivers sweep it into the dustbin of history. Maybe I have that soft spot in my heart for it because it was one of the drivers that the Japanese Mobile community hacked years ago and seeing it the tree reminds me of happy trips to Japan, drinking way too much sake, and speaking bad Japanese as a result? Who knows....
I discovered that the driver didn't work. It didn't work before the patches, nor after them. The breakage was minor and I likely wouldn't have noticed it except for the fact that I didn't have the Ethernet cable plugged in when I was doing the early testing. Since the breakage annoyed me, I went ahead and fixed it. I also noticed that the reading of the EEPROM was very slow, and caused me to drop characters when I inserted the card. I hate that. I discovered a number of DELAY statements in the EEPROM reading which were the cause of the problem. I thought "this is nuts" to myself, and went off to locate the datasheet for this part. After reading through it, I discovered the EEPROM busy bit that I polled in place of the hard coded 3ms DELAY. I went from having about 1.2s of DELAY and other busy waiting when I inserted the card to having on the order of 800us, a speedup of about 1500x.
This brings up a number of philosophical questions. Why did I bother with such an outdated chip? Why speed up a one time operation? Why spend any time at all on this after a busy day of meetings and crisis management?
Let's answer the last question first. I did it because I was absolutely exhausted by my meetings. While productive, and they helped to drive the problems of the project I was working on towards resolution, they were draining. By hacking on this driver I had a very safe area to make improvements. Unless I broke the build, nobody would notice the work, yet I'd have the satisfaction of a job well done. Since it is in an out-of-the way part of the kernel, I had the room to fail without throngs beating down my door. I had complete freedom to tinker and tidy as I saw fit, and doing so was very relaxing and invigorating after a long, hard day. Maybe I'm just weird, but sometimes a little bit of hacking to make something better is just what my brain needs to relax and unwind.
The reason I was spending any time at all on this was that this part made a resurgence in recent years inside embedded systems. There are several embedded designs that use this part when they don't have the ethernet on the SoC. More recent parts have all this built into the SoC, so the popularity has waned once again, but I knew some ARM boards used it, so in the back of my mind I had a justification for spending time on it based on my FreeBSD embedded hat that I wear from time to time. I was shocked to get email from someone who had one of these boards and wanted to know how to write a front end for this driver for that board within a day of my committing the cleanups. That was a nice bonus. Time will tell if he follows through, of course, but I was very amused by it.
Finally, why spend time optimizing an operation that happens only once at startup? I hate losing characters when I type. Since I didn't want to re-write the syscons keyboard driver to have a fast interrupt handler to read the keystrokes and queue them for later processing (the only thing that will interrupt a DELAY is a fast interrupt handler), I thought this was the easier path to solving my problem. I spend a lot of time at work making sure that the right priority calls are made, and it felt good to be "bad" and work on something that clearly is the wrong priority call in terms of everything else that's going on in FreeBSD.
I guess it all boils down to "I had an itch, and it felt good to scratch it." rather than any rational thought process. Sure, I justified it after the fact in many different ways, but it felt fundamentally good to just make something better for the sake of making it better and not have to worry about big picture this, or deadline that, or you broke my whatsit complaints. I had a well defined technical problem, I had to research solutions and hack a bit of code. It felt good being able to find the data I needed, fix the code, test it and see it working and passing packets again. I wish all problems that I faced in my technical life were so easy and rewarding.
Oh yea, and it turned out that I found a bug in John's patches and he was able to commit them to the tree, eliminating one more Giant Locked driver. I'm sure Robert will be happy. I'm sure there are others that would have been just as happy to have the impending removal of Giant Locked network drivers sweep it into the dustbin of history. Maybe I have that soft spot in my heart for it because it was one of the drivers that the Japanese Mobile community hacked years ago and seeing it the tree reminds me of happy trips to Japan, drinking way too much sake, and speaking bad Japanese as a result? Who knows....
20080531
Plat'Home provides OpenMicroServer
Plat'Home has generously shipped me an OpenMicroServer. Plat'Home has been doing Emebedded things for years in Japan. They used to have the coolest store to go visit in Akihabara, but that recently closed and now they are expanding their markets internationally through the web. I have fond memories of buying my first HappyHackingKeyboard there almost a decade ago...
So what is an OpenMicroServer? It is a ruggedized router with extra features to allow it to operate in a wider range of environments than just a router. It has DIO pins for control and monitoring. There's a console serial port, as well as an extra serial port. There's three multicolored LEDs as well. It operates over an extended temperature range. Inside there's a CF slot in case the built in flash is insufficient for your needs. Oh, and I almost overlooked the pair of USB 2.0 ports.
Under the hood there's an MIPS cpu inside the box, which is why they send it to me. I've started working on FreeBSD/mips support for it. There's a RMI Alchemy™ au1550 400MHz powering this box with 128MB RAM and 16MB Flash. It supports 3 ethernet ports. 1 10/100 port that also supports POE (to get power over the ethernet) and 2 that are 10/100/1000 gigE ports.
The only bad thing I can say about it is that it ships with Linux preinstalled... :-)
You can find more information about the specs here. Or general information about Plat'Home here.
Stay tuned for updates on how the port is going.
So what is an OpenMicroServer? It is a ruggedized router with extra features to allow it to operate in a wider range of environments than just a router. It has DIO pins for control and monitoring. There's a console serial port, as well as an extra serial port. There's three multicolored LEDs as well. It operates over an extended temperature range. Inside there's a CF slot in case the built in flash is insufficient for your needs. Oh, and I almost overlooked the pair of USB 2.0 ports.
Under the hood there's an MIPS cpu inside the box, which is why they send it to me. I've started working on FreeBSD/mips support for it. There's a RMI Alchemy™ au1550 400MHz powering this box with 128MB RAM and 16MB Flash. It supports 3 ethernet ports. 1 10/100 port that also supports POE (to get power over the ethernet) and 2 that are 10/100/1000 gigE ports.
The only bad thing I can say about it is that it ships with Linux preinstalled... :-)
You can find more information about the specs here. Or general information about Plat'Home here.
Stay tuned for updates on how the port is going.
20080426
More mips support code committed
This weekend, I've committed more mips support code. Everything except for the tool chain is now in the tree. The tool chain will be pushed in over the next week or so. I have to verify that some changes I remember having to make to the tool chain are compatible with the tool chain that's in the FreeBSD repository. When everything has been pushed into the tree, I'll enable it as part of the make universe target.
FreeBSD/mips is starting to get attention from other FreeBSD developers now that it is in the tree. Alan Cox has started to audit the Mips pmap, for example. This should help FreeBSD/mips transition to the next level of support.
Many changes are still needed for the mips port. We need to audit the basic libc functions to make sure that we haven't stubbed anything out that's going to bite us in the future. We need to look to see if there's anything that can be refactored from the 3 different embedded platforms in the tree today (powerpc, arm and mips). Better documentation and porting to new chips/boards would help us to make things more portable.
FreeBSD/mips is starting to get attention from other FreeBSD developers now that it is in the tree. Alan Cox has started to audit the Mips pmap, for example. This should help FreeBSD/mips transition to the next level of support.
Many changes are still needed for the mips port. We need to audit the basic libc functions to make sure that we haven't stubbed anything out that's going to bite us in the future. We need to look to see if there's anything that can be refactored from the 3 different embedded platforms in the tree today (powerpc, arm and mips). Better documentation and porting to new chips/boards would help us to make things more portable.
20080414
FreeBSD/mips entering the tree
I've started committing FreeBSD/mips to the tree. It includes support for the ADM5120 SoC, a generic MIPS 4Kc in a Malta board, the IDT RC32434 (found on RB533) and preliminary support for the Broadcom Sentry 5 series of CPUS. It will likely be a few days before it is all in the tree and buildable. There's a number of issues that are cropping up as I'm pushing the code into the tree that weren't apparent until after the commits and merges back into p4. In addition, support for another platform is delayed pending approval to commit.
Look for more news, how-tos, etc in the days and weeks to come.
Look for more news, how-tos, etc in the days and weeks to come.
20080327
Tokyo AsiaBSDCon 2008 Dev Summit Day 1
Hello from Tokyo.
Today we had a developer summit at AsiaBSDCon 2008. We talked about a number of items. We talked about the FreeBSD/mips: it is booting multiuser. We'll be committing to FreeBSD soon.
We talked about ways to making it easier to have parts of FreeBSD be optional, with the default being 'on'.
There's this ugly hack which allows one to test the suspend/resume paths of drivers. Check it outthis patch.
Today we had a developer summit at AsiaBSDCon 2008. We talked about a number of items. We talked about the FreeBSD/mips: it is booting multiuser. We'll be committing to FreeBSD soon.
We talked about ways to making it easier to have parts of FreeBSD be optional, with the default being 'on'.
There's this ugly hack which allows one to test the suspend/resume paths of drivers. Check it outthis patch.
20080320
D-LINK DIR-615 B2 hardware
If you go buy a D-LINK DIR-615, make sure that it is hardware revision A1. Hardware revision B2 has less flash (only 4MB) and RAM (16MB) and a completely different processor: Ubicom IP5090U cpu. This CPU uses a new instruction set (ubicom32) that isn't supported by any open source operating system that I could find. This is also the previous generation of the ubicom processor. The IP51xx is the latest generation of processor, and evidentially its only used on the DIR-655.
A good place to look for information about what processors and radios are in the different access points on sale now, including version information, can be found over at small net builder with information about the D-LINK DIR-615 B2.
A good place to look for information about what processors and radios are in the different access points on sale now, including version information, can be found over at small net builder with information about the D-LINK DIR-615 B2.
20080318
D-LINK DIR-615
The other day I saw that Target was selling the D-LINK DIR-615 draft N router for $50.00 each. Since it had been a while since I purchased a wireless router to hack, I bought one. It turns out that this was a wise choice.
This router chip has an 88F5180NB1 CPU. This is a Marvell Orion SoC. Support for this family of processors is coming into the tree shortly.
There's a FS28F640 flash chip on board. This is a 64Mb/8MB of memory. With compression, FreeBSD can fit into this size. There appears to be 32MB of RAM, which is also enough to run FreeBSD.
There's a 88E6061-LAJ1 PHY chip which should be relatively easy to program.
Finally, it has a mini-pci slot with a 802.11n card based on the 88W8361P-BEM1 chip. Maybe a driver for this chip will come along. I've not investigated the GPL tarball to see if there's a driver in source for this, or just a binary module.
There's a GPL tarball available at the D-Link web site.
Finally, there's two interesting connectors. One looks to be a JTAG connector, the other looks to be a serial port.
My next step is to look into what's coming out of the serial port and what's in the GPL tarball for hints while I'm waiting for the Orion support to come into the tree.
This router chip has an 88F5180NB1 CPU. This is a Marvell Orion SoC. Support for this family of processors is coming into the tree shortly.
There's a FS28F640 flash chip on board. This is a 64Mb/8MB of memory. With compression, FreeBSD can fit into this size. There appears to be 32MB of RAM, which is also enough to run FreeBSD.
There's a 88E6061-LAJ1 PHY chip which should be relatively easy to program.
Finally, it has a mini-pci slot with a 802.11n card based on the 88W8361P-BEM1 chip. Maybe a driver for this chip will come along. I've not investigated the GPL tarball to see if there's a driver in source for this, or just a binary module.
There's a GPL tarball available at the D-Link web site.
Finally, there's two interesting connectors. One looks to be a JTAG connector, the other looks to be a serial port.
My next step is to look into what's coming out of the serial port and what's in the GPL tarball for hints while I'm waiting for the Orion support to come into the tree.
20080316
FreeBSD/arm on a Linksys NSLU2 (slug)
Thanks to some encouragement from Gavin Atkinson, I have been able to boot the AVILA kernel on my Linksys NSLU2 (slug). I have it running of NFS root at 266MHz. Not super fast, but not too bad. I need to clean up a bunch of stuff still, but at least I have the basics working.
I'll post more in a few days, once I get a chance to clean up what I have and submit it to CVS. But this is very exciting...
I'll post more in a few days, once I get a chance to clean up what I have and submit it to CVS. But this is very exciting...
20080312
Buffalo LinkStation PC-L4PWAP
Today I'm writing about the Buffalo LinkStation PC-L4PWAP. It was on clearance at Circuit City, so I thought I'd take a chance and pick it up. At the very least, I'd have a new 'receiver' on my network to play tunes through at parties.
I cracked it open when I got it home. There's a Phillips PNX-1520E processor running at 300MHz inside. A quick web search turned up that it has a TM3260 CPU core with a lot of perripherals (I2C, PCI, IDE, etc). The TM3260 is a CPU from Phillips that is a VLWI processor. I had rather hoped when I saw pnx that it had one of their MIPS cores in it. But no such luck.
I didn't bother looking at the amount of memory or the amount of flash on the board once I discovered it wasn't MIPS based. I guess I'll have to content myself with listening to the music it is spooling off a uPNP server on my network... once I get one of them setup. I'll report back on how well it works.
I cracked it open when I got it home. There's a Phillips PNX-1520E processor running at 300MHz inside. A quick web search turned up that it has a TM3260 CPU core with a lot of perripherals (I2C, PCI, IDE, etc). The TM3260 is a CPU from Phillips that is a VLWI processor. I had rather hoped when I saw pnx that it had one of their MIPS cores in it. But no such luck.
I didn't bother looking at the amount of memory or the amount of flash on the board once I discovered it wasn't MIPS based. I guess I'll have to content myself with listening to the music it is spooling off a uPNP server on my network... once I get one of them setup. I'll report back on how well it works.
20080110
Spot the Bug!
I was looking over some code for someone today. They were having problems with preemption in the write routine and couldn't understand why, since they said to take Giant for all devsw operations. In digging into the problem, I discovered the following code. Maybe you can spot the bug:
#ifdef D_NEED_GIANT
#define FOO_GIANT D_NEEDGIANT
#else
#define FOO_GIANT 0
#endif
(FOO_GIANT is used in the devsw data structure to paper over differences between 4.x and 6.x in this driver).
I think I know who did this change, but without cvs access to the code I can't be sure. Which is good, because I think it was me, but it might have been the person I was helping out. The change was made almost 4 years ago. This code has been in there that long and it wasn't until an especially demanding application came along on a faster CPU was it a problem.
Just goes to show you can never be too careful, or test too much...
#ifdef D_NEED_GIANT
#define FOO_GIANT D_NEEDGIANT
#else
#define FOO_GIANT 0
#endif
(FOO_GIANT is used in the devsw data structure to paper over differences between 4.x and 6.x in this driver).
I think I know who did this change, but without cvs access to the code I can't be sure. Which is good, because I think it was me, but it might have been the person I was helping out. The change was made almost 4 years ago. This code has been in there that long and it wasn't until an especially demanding application came along on a faster CPU was it a problem.
Just goes to show you can never be too careful, or test too much...
20080105
Random Acts of Kindness
I went to my old house yesterday. Like many others, my old house hasn't sold in a while. There was a showing today, so I had to shovel the snow off the driveway. While I was there I discovered a most interesting package on my doorstep.
It was a nice, large calendar of African animals in the wild. I hadn't ordered the calendar, so I was very confused. It was from Cafe Press, so I thought it was a dividend from an item I'd designed and put up there. But after shoveling a little I realized that couldn't be it: I've just bought stuff from Cafe Press in the past. I hadn't designed anything for there. I'd thought about it, but never put my thoughts into actions.
After I finished shoveling, I took a closer look at the package. I found a card I'd overlooked before. Inside the card there was a nice note thanking me for the USB and other bits of FreeBSD work I'd done. It was anonymous, so I don't know who to thank for this bright spot in a busy day.
It is the little things like this that really make my involvement in the open source community enjoyable.
Thank you!
It was a nice, large calendar of African animals in the wild. I hadn't ordered the calendar, so I was very confused. It was from Cafe Press, so I thought it was a dividend from an item I'd designed and put up there. But after shoveling a little I realized that couldn't be it: I've just bought stuff from Cafe Press in the past. I hadn't designed anything for there. I'd thought about it, but never put my thoughts into actions.
After I finished shoveling, I took a closer look at the package. I found a card I'd overlooked before. Inside the card there was a nice note thanking me for the USB and other bits of FreeBSD work I'd done. It was anonymous, so I don't know who to thank for this bright spot in a busy day.
It is the little things like this that really make my involvement in the open source community enjoyable.
Thank you!
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