---
title: WWDC2003 Session 505
framework: wwdc
role: article
path: wwdc/wwdc2003-505
---

# WWDC2003 Session 505

## Transcript

Kind: captions Language: en we have two firewire sessions this year like we do every year one is more in depth and focuses on writing software the other is more introductory and this year focus is a great deal on firewire 800 but this year they are in reverse order so you haven't missed anything the next one is tomorrow at 9am I'm sure you'll all be up bright and early for that what this session is about is writing firewire software we're going to talk about what in Mac OS 10 how the fire wire services work what's available for you to tap into where you can hook your software in two hours and we have a new focus this year on a number of topics more in-depth for example we'll look at how isochronous transmitted really works which we've always glossed over in the past and we have a bunch of new tools for you that I think you'll be really interested in so let's launch right into this wasn't expecting this to be tipped over it like that we're going over the architecture first look at the layers of firewire software the various modules how driver matching and loading works where you can hook in how you develop software then we have special sections on tcp/ip the internet protocol running over firewire some detailed examples of how isochronous transfer works what dcl really is and what happens when you run one will look at new AVC services including new ABC target support that add some great new capabilities we'll talk briefly about SVP tree which adds a new performance capability and then we'll have a detailed look at some new tools and other support that we have for you to help you develop for firewire on Mac OS 10 let's start with the architecture see if this thing works here's the stack showing various elements in Mac OS 10 firewire the four that are brightly colored are the core services that are provided by the firewire software team and some others are shown around them for context starting at the bottom you see the silicon that represents the firewire interface and the power macintosh system the five which we'll talk more about later and the ohci chip together that's what you typically find on a firewire card when that's detected our services load in the colonel pretty much all the firewire is in the kernel because firewires a resource that we can boot from we can take a page fault from a firewire device so it's got to be there in the colonel similarly our IP networking services have to be in the colonel so we'll go over the layers in the kernel and we'll also talk about how you can hook into that from user space up on top you can see the three layers in the kernel there the controller hooks directly onto the hardware the family pulls everything together the protocol layers where we start to differentiate into SB p2 or ABC and then the user client interfaces up on top let's start with the family right in the middle the family is the layer that brings everything together you've got multiple firewire devices multiple drivers multiple applications they all want to use the same firewire bus at the same time well there's only so many DMA contexts in the dress space and interrupts and so on you don't want them trying to know what each other are doing you want the mall to function independently that's what the family does it lets the different drivers make their requests accuse them up and send them on the bus when packets come back in it figures out which packets go to which drivers hands them out accordingly so your drivers don't have to tiptoe around each other you can write just to do your thing and not worry about everybody else that's what the family is for the family also provides some basic management services for example e the family may tune the performance of the firewire bus to optimize some of the hardware settings the families provided in kernel extension called io firewire family text and there's going to be one of these for each firewire bus in your system typically you only have one firewire bus in the system but if you want you can have more than one the layer below that is the controller this is what glues to family to the hardware in your system in most systems this will be apple fw ohci the colonel extension although in certain very old systems it will be Apple links such as on the blue and white g3 the controller actually knows how to program DMA knows how to handle interrupts and knows how to do all the hardware specific stuff this is the same whether you have an integrated controller like Steve showed yesterday in the in the new g5 architecture where the firewire controllers just built into the chipset or if you have a pci card or card bus card it's all the same as a controller layer now as I described all those things sharing the family everything they do have to go through the controller the controller cannot be subclassed even though it's in the colonel this is a location that has to please everybody so if you go in there changing it to please your device you're probably going to make someone else unhappy so don't even think about trying to sub classic controller this does mean if you make a din cards be sure to pick silicon that works now moving up from the family protocol this is where things start to differentiate if you're a camcorder or an iPod or a printer you start to have a different personality at this layer for example SBP the serial bus protocol is what's used by storage devices like the ipod hard disk drives it's also used by others guzzi type devices like scanners or printers on fire wire in comparison the AVC command set is used by camcorders TV set digital bcrs sort of consumer electronic devices each of these has a service layer that sits on top of the firewire family that provides all the basics of that protocol so that you don't have to reinvent it from scratch just to communicate with that particular device these letters also perform protocol specific matching services now we don't have our own matching musieo kit for everything but these layers know how to take a closer look at say an ABC device and figure out what subunits it has is it a tape or a VCR or a TV this information goes into the registry so that you can use i/o get to match properly to your device finally outside the kernel we provide a variety of user clients officially these are known as device interfaces but everyone seems to call them user clients so we'll do that here this is a way to cook in to all the fire wire services in the kernel from an application or from your plug-in that's running in the context of an application in user space just about everything you can do in the colonel in firewire you can also do from user space and you'll find it's usually a lot easier there's direct api's for sending and receiving packets you can also access the protocols like SBP and ABC for userspace when you do this you're not using a copy of the services you're not using some user safe version of the services you're using the real SBP to or the real ABC that's in the colonel so you're going to get the exact same behavior the same performance places where buffers have to move across the user colonel boundary we mapped memory we don't copy your data across we just map it directly into the DMA their data moves as fast as it can writing and debugging your software out and user space is much easier than doing so in the colonel so please do that if you can somebody wasn't listening to the announcement before we started about cell phones now how does driver matching work as i said we use standard i/o kick services there's nothing special about firewire like we had mac OS 9 where we had our own unique firewire matching in Mac OS 10 it's all just I Oh Kip but we put firewire specific information in the i/o registry so you can find the unit directory in your device or the vendor ID or the GUI doll the firewire information that you expect the firewire family discovers nodes on the bus that have configuration roms and create a device object for each one of them in the i/o registry it then scans the ROM further and if it finds unit directories it creates unit objects typically one per device but there could be more than one the unit is where you start to differentiate whether you become SBP two or a PC or something else so the appropriate protocol layer load and it takes a further examination of the device if the SBP to layer loads like is shown in the picture it will create a target object then it will scan the device further and create logical unit objects with SVP specific information such as the device type whether it's a disk or a tape or a printer so the matching is iterative these items build up one by one in the registry at each stage you have the opportunity to do active matching if you need to actually talk to the device and find out whether it's really the one you want to drive if you're working in the kernel you can do subclassing at the various layers as well in addition to the devices we find on the bus there's also a device in the registry called the local node the local node is there whether anything's plugged in or not it represents the Macintosh itself but it doesn't mean you're talking to yourself it's just an all-purpose portal onto the bus if you want to talk to a single device out there you should probably match against that device but if you're talking to several devices the local node gives you a way to do that for example IP / firewire or the em lam protocol or multi node cluster computing the local node might be a good way to hook in for those because it's always there no matter how many or how few devices are plugged in on the bus for you to talk to just like everything else you can also use the user client on the local node now that you've seen the layers and you know where to hook in where exactly should you develop your software your first choice should be to write software out in user space as I said just about every service that we have in firewire is available to a user client in user space io firewire lib is the primary user client it has direct access to all the packet send and receive services and the specific user clients for ABC and SBP that are listed here as well however if you're looking to use SBP you may instead want to use the fuzzy task user client we'll talk more about that later but if your device complies with sam discuz the architecture model scuzzy task user clients going to be a lot easier than spp to user plan if you're working in user space we have lots of sample code available if you've installed the firewire SDK you can look in this path and you'll find all the sample code for writing drivers and applications out in user space now I said writing in user space should be your first choice you only actually have two choices writing in the kernel is your last choice you really don't want to do this if you can avoid it all fire wire services are available and you may need to write in here if you're writing a bootable driver although we provide one for you so you shouldn't have to if you're writing a networking driver same caveat or something else that supports another colonel service but many kinds of things simply can filling the colonel you can't put a printer driver in the colonel it just there's no way to hook it into print center the same goes with a scanner driver but if you need to write in the kernel you can and that may give you the opportunity to subclass some of the layers that we have in the colonel for example we do this fairly extensively in the mass storage class we sub class so that we can provide the best possible support for each of the different kinds of bridge silicon that's out there in firewire hard drive sample code for working the colonel is limited basically all we have to offer is the source code for firewire itself which is in Darwin so you can start there and you'll see how it works and you can figure out how to look into it debugging and testing is more difficult in the kernel than in user space if you crash in user space you can just run again but if you crash your driver in the colonel you'll get to reboot the machine that'll give you some time to ponder when you left and your backups so you should really develop out in user space if you can if that wasn't enough incentive here's all the sample code that we have now in SDK 16 once you've installed SDK 16 that path is where you'll find all of this there's some very general purpose sample code like fw sample project very non-specific io firewire lid basics do you want to cause trouble you can start with the reset storm sample code we have some new stuff that's very exciting the dvhs capture sample and the firewire MPEG if you have a firewire devices like a digital VCO or firewire TV try these out you'll find some really interesting new capabilities there so whatever you're trying to do we surely got something on this list that's a good starting point now I mentioned scuzzy task user clients and Sam lots of devices that use SBP to also comply with fuzzy architecture model so fuzzy task user client may be a lot easier for you if you use SBP to user client you have to deal with bus reset logins reconnect and so on all that's handled for you in scuzzy task use our client you can just form the commands or task and hand them down to have them executed so if you'd like to try that this shows where it's located it's inside iOS because architecture model family checks if your device is some kind of optical media burner you may want to move to an even higher level we now have a P is for disc recorded for DVD r tdr and so on you can find documentation as listed there that would be generally even easier than using scuzzy task and certainly been using SBP too now if your device has some SBP to unique behavior or it doesn't quite SBP to then you may need to move back down the software stack and use SBP to itself or even the basic firewire api's but whatever your device does there's some way we provide that you can hook into it and they may be several ways to choose from new this year possibly late last year tcp/ip the Internet Protocol we now support this on fire wire this is an industry standard I Tripoli standard 27 34 is very straightforward it's only a few pages it shows how to send IP datagrams on fire wire you can get it at the I Triple E website if you want internet data grams are simply packaged up and firewire block right each firewire node that supports IP allocates an address in its own address space where it will receive these packets and that address is published in the nodes configuration ROM so that other nodes on the bus can discover it so our driver finds all the other nodes that speak I pee and then can send data grams to them broadcast packets are supported that's used for example for our plea address resolution protocol that's done with a firewire a synchronous stream packet it's like an isochronous packet but it's not sent in real time so no reservation is required so it's fine for arc it's also very low bandwidth so it doesn't interfere with anything else I Triple E 1394a set aside isochronous channel number 31 for this purpose and certain related purposes if you have a device that's hardwired to channel 31 I don't know of any you're going to have to move to another channel but you'll see these packets and Firebug as isochronous Packers they're actually a synchronous stream Packard's Firebug can't tell whether it was tenth in real time or not it only knows when it arrived so it shows it as if it was isochronous so what's this good for the internet good for a lot of things everyone you ask will have a different favorite use there's no restriction here we support IP so anything that runs on IP should run on IP over firewire HTTP protocol file services like FTP or AFP whatever you want now you may find this interesting if you're presently using target disk mode using AFP or personal file sharing maybe you may want to investigate that is it after that depends you don't have to reboot twice so that may help but you do have to login and setup personal file sharing the actual performance is likely to depend on kinda files you're moving how much of the CPU you're using and so on so give us a try you may find it to your liking many cluster computing api's use IP because it's ubiquitous nobody makes a computer that doesn't have tcp/ip are they certainly don't sell very many of them so if you have a cluster computing application that you'd like to run on firewire and it's based on IP you can run it immediately on IP over firewire however firewires direct memory access model where memory space is visible on the firewire bus is very well suited for certain kinds of cluster computing that exchange a lot of data between the nodes if that's the kind you're doing IP will work but you may get the best performance by going to a firewire native solution so how do you get this configured like any other IP interface you start in the network craft control panel sorry Mac OS 9 term network preferences panel in the upper left this is a pop-up menu called show if you'd pick that at the bottom there's always something called network port configuration you probably mostly tried this once you pick that you'll find firewire is in your list of network port unless you're running mac OS 10.2 in which case you may instead find ethernet adapter en tu we're working on that if you see that just double click on it and rename it to firewire once you've done that and be sure to turn on the checkbox you can then drag firewire to the top of the list if you'd like to use rendezvous to automatically provide an IP address for your firewire port just drag it up to the top like is shown there then if you'd like to further configure it go back to the network port pop up and just pick firewire from the list and you can select your IP address or whatever else you like now in Mac OS 10 dot too it will allow you to configure appletalk and pppoe not f e and neither of those make any sense on fire wire so ignore those you can try to set them up but they won't do anything we fixed this all in mac OS 10.3 here's where we have deployed support for IP on firewire there's two Developer Preview releases they're available through the ADC website and buddy can download those they run on 10 25 it is also included in Mac OS 10 server version 10 25 and it's pre-installed on every xserve in mac OS 10.3 it is pre-installed for everybody using the seed that you received from this conference you can go turn it on and try it out right away in Mac OS 10 version 10.3 we have fixed all the little user interface issues because we were able to change everything at once rather than just adding our new text and we've added support for ipv6 and we've improved the performance quite a bit let's look at that now this is somewhere where the ethernet guys have a big advantage over us ethernet is an IP network hardly anyone uses it for anything else ethernet hardware is designed for optimal transmission and reception of IP datagrams firewire hardware is not it's designed to do everything ipod camcorders still cameras TVs it can do a lot of things really well but it's not customized for IP so we had a little bit of a disadvantage when we started so how do we do in the first preview release our standard benchmark is to run net / between two x servers the first preview release on 10 24 could get 216 megabits per second that's more than half of the firewire bus it's not bad and in fact if you were running this on your ibook or your eMac that's twice as fast as the built-in 100 megabit Ethernet port so this already may be very useful to a lot of people but of course we'd like to go faster in the second preview release and booked in Mac OS 10 25 server what got that up to 277 megabits per second we're never going to hit 400 those overhead those arbitration of acknowledgement we're going to get somewhere in the 300s but we're never going to hit 400 but we're going to keep trying so how have we done for macro is 10.3 same test we're now up to 317 megabits per second and if you hook up to firewire 800 ports that are now included on the xserve we're getting 660 megabits per second now these are preliminary and their benchmark numbers so nothing will ever go this fast in real life but you can see we're making it a lot faster and its really getting very competitive with gigabit ethernet so if you want to run IP on firewire we think put you in pretty good shape to try that out next isochronous services every year we talked about the fact that we have I saw Korean services we say they're complicated and kind of gloss over how you actually use them this year we're going to go into depth and try to explain the basics of how it works we have something called a data stream control language dcl isochronous transfer on firewire sends or receives 8000 packets per second each one is very precisely spaced on the firewire bus you wouldn't want to do this through some kind of system call API 8000 system calls per second even if you can do it is very expensive and it's going to be almost impossible to get them at the right time and meet your real time guarantee so that's just not how it's designed nobody's ever done it that way we have hardware that can send to receive the packets according to a fixed program of when they should appear but that hardware is also complicated so it has different register steps on different models of Mac requires taking interrupts knowing physical memory addresses you don't want to be exposed to it that's what dcl solve a dcl is an abstract description of data flow on firewire a dcl program that you write in memory describes on a packet by packet basis how where and when you'd like to send or receive data you write the program you hand it to us we figure out how to make the hardware do what you're told us to so it's very precise it gives you packet level control but you don't have to make frequent system calls you don't have to hit field time guarantees yourself at least not 8,000 times per second so a dcl program is a linked list of operations and they're going to execute in the order of the length lift each operation in there does one basic thing sends the packet or receives a packet so you can't mix those in a single program or it may invoke a call back to tell you that it's reached a certain point in a program or it may jump to another dcl if you don't want to run the program exactly in the order if it's written for example you can make a loop and jump back to the top so you keep going we will compile your dcl program to execute natively on whatever Hardware we actually have but because of this there are some restrictions to what you can do while the programs running if you make changes to the source they won't necessarily affect the DMA unless you tell us what you've done and there's some limitations on the kind of change you can make here's a picture here's a dcl shown on the left as a linked list of operations the solid arrows pointing down are the linked list very important at the bottom you can see it links to 0 if you link it back to the top the compiler will hang trying to find the end of your program so please don't forget to link it to 0 at the end the last instruction though is a jump instruction and you can see the dotted line going up to the top which is a label instruction this causes the program to run in an endless loop even though it's only actually about nine steps long this program sends data continuously all of the operations that move packets are send operations each one points to a buffer that contains a packet interspersed between the send operations are called proc operations after sending three packets this program will call will cause your callback to be executed and you'll know that those three packets have been delivered onto the bus this gives you the opportunity in a looping program like this to update those three buffer so that the next time to they send something fresh time waits for nobody and neither does the DMA it's really important to understand when you write these programs packets number one two and three are sense approximately 125 microseconds apart on the firewire bus and then we call your fallback but we also send packet number 4 we don't wait for your call back to finish your callback may not have even started yet when we get to packet number 4 if it's on your work Luke when you're waiting for something else to run the DMA is going to march through those packets exactly on time according to the firewire clock this means if your callback is going to fill in new data for buffers number 1 2 & 3 you have to do so quickly now an ordinary program is not really this small this program sends only three packets then the callback so at 8,000 packets per second you'd have 2,700 callbacks per second that's really a little too fine grained typical program will have 20 to 200 packets for each call back and that depends on the latency that you need in processing the Packers typical program may also have more than two clusters it might have three or four so that you have a little more time there's less danger of the DMA wrapping around and capturing you by surprise there's another thing in the program that i'm not showing because it doesn't fit on that slide so let's zoom in very important is an update dcl if you change the contents of one of the transmit buffers while the program is running we need to know about it in particular we usually have to bite swap the header so that the transmitter will be able to pick it up over pci where everything ends up getting bite swapped so after every call back in the transmit program typically you'll have an update this doesn't take any time from the dma's point of view still just marches through from send number three to send number for the update though tell the firewire family that some previous or some details and the program may have changed the update instruction has a list of pointers to other instructions you can see here it points to the three send operations just before you don't have to tell us what changed we'll figure that out because we know what kind of operation they are but you do have to tell us when they've changed the callback will execute to completion before the update happens they're both done in the CPU so even though the DMA may have marched on many packets into the future your callback will finish before the update happened in a transmit dcl you have to update the packets before they get sent in a receive dcl you have to update the package after they've been received but before you look at them if you don't do this or if you get out of sequence with the update you may find packets that don't make any sense because we haven't bike swap the headers or done other necessary adjustments detail programs don't have to loop you could have a one-shot program that's very rare or you can change the jumps on the fly in order to keep feeding new data to the dcl engine without ever actually making a loop that's what our DV transmitter does you'd never want to send stale DV data every packet has a sequence number in it so we make sure that the program always ends somewhere and if we fall behind the DMA is going to hit the end and stop so we won't confuse any TV or camcorder will just stop sending data of course our goal is to never let that happen and just keep running which we usually do there's another operation called a time stamp this is something you can insert into the program if you want to find out exactly what time it was when the DMA reached that point you could use a time stamp which returns the firewire cycle time to synchronize to programs or synchronize a program with some external activity or to make sure this program is really running on time and they're not losing packets or having some other problem time stamps also have to be updated before you look at them because they're generated by hardware so they may come in light swapped or they may need other modification before they're accurate in macro 10.3 we're adding a new kind of dcl details were invented about seven years ago back when we didn't have ohci so they're very flexible so that we had room for growth now we have ohci everywhere and that's not going to change so we have adapted details to really fit well on no HCI previously there were a lot of hidden rules in dcl like a label had to be immediately followed by a send or receive op the compiler didn't enforce that but if you forgot your program wouldn't work it wasn't hard to code around these rules but it was hard to remember to follow them the new style dcl mapped much better to the hardware so they don't have this kind of rule the new style dcl has one operation for each cycle it's going to send or receive a packet or do nothing at all if that's what you want and for that one operation you have won call back if you want it one update one time stamp you get one of everything this is being added Mexico if 10.3 it's not yet in the SDK but we will have it out there soon because it Maps there's a hard where we can now do some new things too that we couldn't do before in particular we can give you the error status for any particular packet which may be very important if you have to check back data integrity and we can let you change the length of the packets in the transmit program which was really difficult to do before the old style of dcl will still be supported but they are compiled into the new style so if you're doing anything new as soon as the new style is available you should try to use it we have new services for ABC first of all if you need to manage plugs these are connections established between devices on the firewire bus that represent an ongoing data flow I saw currently between two devices we have api's now to make that easier you can call these api's to establish input or output plugs and we will take care of them so that they remain set up every bus reset requires every bus reset invalidates all the plugs that are out there and have to be reestablished so if you've used these api's will do that for you you don't have to keep tracking them so that should make it easier we've also added a lot of stuff to help you become an ABC target up till now the Mac has been really good at telling other devices what to do camcorders should play tuners should go to channel 37 and so on but ABC some of those devices want to control the Mac or they may if you write software that makes the max do something interesting when they talk to you so we have api's to help you do that publish ABC unit directory causes the Mac to publish in its own config ROM a unit directory telling everyone that it speaks ABC and you can send commands to it and subunit adds an ABC subunit to the Mac so that when someone asks us what sub units we have will respond accordingly that we have a tape sub unit or a tuner subunit or whatever it is that you've added now you'd actually call those in the reverse order first add your sub units then publish otherwise you may start getting requests before you're ready the publish API will cause the bus reset that's how AVC lets everybody know that something new is available or might be saleable if you want to handle commands that come in say to the subunit that you've added you can use these api's you can install a command handler you can specify which subunit and which opcodes you're going to handle and this wild card so you don't have to enumerate everything and very important most things that you get require some kind of response so you can now call send ABC response to send that response back to the device to tell it what happened with that commands it get sent to you we handle all of these commands automatically but there is a mechanism for you to handle them too if you know what you're doing for example unit info and subunit info there at the bottom we handle those based on the subunits you've added we automatically respond and say yes we've got one of those here's a list of the existing ABC api's before we went and made all these changes all but one are still available we have deprecated the one at the bottom set ABC request callback that was the old way to handle incoming commands and it really wasn't right so if you were using that you really want to use new functions instead SBP three this is a new revision of the SBP to standard that's the standard use for hard drives ipods swords devices on firewire we've added support for something called fast start if you've watched in firebug and SBP to device you may have noticed it takes up to five packets just to get the device to start doing i oh you sent it the orb pointer it asks for the orb you send at the orbit asks for the page table you send at the page table finally it can move some data that's ok if you're moving megabytes of data but for small iOS it's really expensive fast start defines a way to send all that information in a single packet the drive can immediately start moving payload we have measured a 30-percent performance speed up for optimal iOS using this technique so it's definitely worth having this technique is in ballot now within an Z which is the standards group that owns it ESP fast start has been stabilized which means nobody's going to change it in fact we've been supporting it since 10 20 for now your device has to understand this new packet you can't just turn it on and it goes stir but if your device does understand this new packet publish the appropriate key in your configuration ROM so that we know you understand it and we'll send you fast start packets if you're doing hardware that does this we'd like to hear from you because we've only seen one so far so please let us know we'll try it out and see if it works now that's covered new and more detailed information about what's in fire our software mac OS 10 for you to develop with let's talk about some of the resources we provide to help you do this software development kits we've made 16 of these so far it's our biggest product for you developers it has lots of sample code I showed you the list earlier the SDKs often have pre-release versions of the firewire text so that you can try out new api's or new bug fixes before your customers are exposed to them the SDKs also have tools utilities and lots of documentation to help you program on firewire these have always been available for free public download at the URL shown on the slide we have something new in the past year the firewire reference platform this is completely independent from our Mac os10 firewire this is a software stack that can run on embedded devices so if you are making a set-top box or a TV or firewire multifunction printer take a look at our reference platform you'll find a lot of code especially for the ABC protocol and command sets they can give you a big head start for implementing firewire on embedded systems there's also a session on this later this week we hold several developer events for firewire we have plugfest at macworld and here at dub dub DC in fact we had 40 devices submitted that are now being tested by the 1394 ta4 plugfest testing and we will bring them all Thursday during the campus bash down at Apple plus you're welcome to bring additional devices then we'll plug them all in we hold developer kitchens this is where we bring our core engineers and meet with your engineers for two to three days of hands on debugging development often we introduce new SDK the new API is that these sessions these have been held in tokyo in cupertino we've done about 10 of these so far we hold these on demand so when you're ready for one of these contact apple developer relations let us know and we'll try to schedule one and we participate in 1394 ta interrupt workshops these are like slugfests only they're much more rigorous there's three kinds of testing done at these events pairwise testing of each device against each other device the official test suites which go through the spec line by line electrical test and configure on testing all kinds of things and the grand melee where we plug all the devices together and try to get a 63 node bus to work that's always a lot of fun these happened four times every year there's one in Tokyo usually in april one in taipei usually in october and two on the west coast either in the Bay Area or up in redmond for some reason these are not limited to TA members anyone can come to these there is a slight fee reduction if you belong to the TA but it's not expensive either way we learn a ton of stuff about our own products and other products we've never seen before you should come to these events they're really valuable 1394 ta is an industry trade group that promotes 1394 that's where all the AVC specs come from they also do a lot of marketing and evangelism work so you may want to consider joining the TA if you make 1394 products ok now let's look at some new firewire tools I mentioned this earlier this is related to tools who get to it in a second what exactly is a phy there was a box marked by in that architecture stack right at the beginning by a short for physical layer it's the chip that actually drives differential voltages on the firewire cable and makes ones and zeros and it receives them at the other end and turn them back into bits the Phi acts as a repeater if it has two or more ports and the five perform of the arbitration so there's no software control for the Phi it's all automated it makes the arbitration go very fast in comparison the link layer which in the mac is ohci is much higher level it knows about DMA crcs isochronous time is higher level than fine the Phi does not have a device driver it doesn't it's not programmable but it does have a small register file this is a page from the 1394 a standard that shows the registers in the thigh each one is 8 bits wide but there's some very interesting and mission in there like the status of each of the ports on the five often when you find some unique and interesting thing happening on your firewire bus you may want to look at the five ports to find out why it's doing that unique and interesting thing 1394a defines these bits 1394 be defines a few more we now have a tool that lets you examine these directly this was possible in Mac OS 9 into jumped into max bug but it was really tedious think you'll find us a little bit easier by tool is a real-time browser and editor for phi registers it displays the phi registers just like the specification except each one of those boxes now a checkbox or pop up menu and it has an explanation of what its current value is and what that means hi tool has integrated documentation if you move the mouse over one of the bits like enable fanned by the text from the specification itself will appear at the bottom of the screen telling you exactly how that bit is supposed to work by tool can examine the Phi in your Macintosh or it can reach out across the firewire bus and examine the Phi and other devices if they support 1394a or 1394 be it also provides a continually updated summary of defy it's looking at and the status of all of its ports so you can see devices that are plugged and unplugged in real time Phi tool doesn't require any special Hardware Phi 2 runs on every Mac that we sell it runs on the 1394 ohci controller here's a full screen shot you can see the center portion looks just like the spec down at the bottom there is the text explaining what the speed field means where the cursor is located on line 3 over on the left you have a summary of what all the ports are doing port number 1 is connected the other two are disconnected and there's pop-up menus to pick which interface if you have multiple interfaces and which node if you want to look across the bus at another note so it's really easy to use believe me if you've never tried cocoa programming you won't believe how easy it is to get this kind of stuff working this with a lot of fun and I think you really enjoy this tool even if you don't have problems in your file this tool is very educational just looking at the bits seeing them change finding out what's happening on a running firewire bus we have another new tool for you this is called firestarter this tool was written for plugfest all of the commercial firewire analyzers out there can show the topology of the firewire buff but none of them does it very quickly at it like I mentioned the grand melee where we get 363 nodes on the bus which we've really done some of the commercial analyzers take 30 seconds or more to try to figure out how to draw a picture of that by that time one of them is cause the bus reset and everything's changed system flow firestarter can update it can draw a slightly simpler version but topologically accurate map of the bus and it can update it 10 times per second so it gives you a very real time idea of exactly what's actually on your buff in the picture there you can see on the right a simple ASCII rendering of the bus and on the left various information that's especially applicable to plugfest like how many nodes what's the maximum hop count how long has it been since the last boss reset and what's the longest time we ever survives between bus reset there's also a bunch of data in the lower left it sorts all the nodes and shows you how many rs.400 f200 how many or 1394 be so you can get a very rapid snapshot of what's connected to your bus here's our full screen display this is a bus with just six nodes on it and you can see in the upper right the hierarchy showing who's connected to who here's a pictures one in the plug fest where we got sixty three nodes on the buff I didn't actually have a big enough screen you have to stretch the window down a little bit to see the last seven nodes but it's showing the topology of how everyone's connected to everybody else and I'd like to point out that the bus was stable for I believe more than a minute under that configuration and then we plugged in the 64th node and things went downhill from there we have one more new tool fw busy buff this is a traffic generator fw busy bus can send any kind of asynchronous packet on the firewire buff it can also send bus reset and it can cause bus reset storm it will even enable and disable its own ports to simulate hot plugging it's automated it can automatically ramp up and down the level of activity so you can leave it running over a period of time and test different levels of activity on your bus you can also turn on and off every different kind of packet packet speed bus reset everything that it does all three of these tools work on ohci so you don't need any special hardware here's a full-screen picture of busy buff the sliders at the top let you adjust the intensity level and how quickly it ramps up and down the check boxes in the middle that you turn on and off every different kind of packet and packet speeds and the control at the bottom gives you a brief summary of what's on the bus and what the tools doing at any particular moment plus on the Left we have defy status that is copied from title now fw busy bus can send any kind of packet if you configure it properly it can write garbage data onto physical memory in your mac so be careful what you turn on and what you don't in this tool the default settings are safe now if there are interesting things happening on your firewire bus if somebody's writing garbage data into your memory you might want to examine the firewire bus and see what's going on we have a tool for that called Firebug and I'm pleased to announce today that Firebug is now available for mac OS 10 really there it is Firebug is a real-time packets nupur it can decode every packet on the bus and show them to you in a sort of semi English ASCII way firebug provides precision timestamps to within one cycle time usually much better than that Firebug can decode common protocols like FTP to an AVC so you don't have to pull out the spec and look up hex codes it'll tell you if that's a block read he told the camcorder to play Firebug also provides some simple bus configuration services if you'd like to tune the gap count or cause a bus reset or go poke at the phy you can do that from within Firebug Firebug still requires the ti PCI links interface we made it run on mac OS 10 but osei just doesn't have the snooping hardware these interfaces are still available you can get them on card postcard or PCI card and if you have a really old Mac like the blue and white t 3 it actually has one of those Tim but we not only brought it to Mac os10 we've made a few improvements we've improved the decoding we added a bunch new a bunch of new ABC commands especially the unit info command so you can see when that's happening the SBP to decode can now survive a bus reset almost every time whereas usually almost never survived it would just go back to showing hex because it didn't know what was going on there's a tool called the five register dunk this if you don't have pi tool handy you can just ask Firebug to do the same thing and you can see in the picture there it has dumped out the contents of the thigh in a concise ASCII format we've added node ID filters you can now look at packets only going to or from or between whatever nodes you choose you can select which isochronous channel you'd like to look at you can get my soccer in a summary usually you don't look at our talkers package because those eight thousand per second they're just wiped out to display but Firebug will now tell you even if it's not showing their soccer his packet ah channel 63 has gone active in fact it's active at s100 it's coming from node to its ntsc video so now you'll know something's happening even though you didn't get the display blown away by thousands and thousands of isochronous packets and because it runs on mac OS 10 we've been able to make Firebug support dual processors so now it's even faster than it ever was before so let's demo Firebug on Mac OS 10 may I have number three please there we go it's right here launch is just like that and there it is now this system running Firebug it's a g4 tower so I installed a PCI links pci card into it it's connected to this other g4 tower and you can see the package there as the other g4 tower scans the bus so I'm going to plug in my ipod and we'll feed all the activities that this generates and we'll see that Firebug can decode the SBP to protocol that the ipod is using take the ipod a few seconds to switch from mp3 mode over into disk mode but it should be ready to go right about now there we go Mac os10 is mounting it as a file system so it's reading different blocks it's figuring out that it's hfs+ you can't see it but to do through the icon on the desktop of Rama Sodor Mac you can see here some of the new features in the decode of normal command orb there at the bottom it says read one block at lb a 900 III C so you no longer have to figure that out for yourself from those 12 like to text under command additionally I can cause a bus reset and Firebug and then go ask this max to do something with the ipod and you'll see that it's still decoding the command even after the bus reset which almost never worked before I mentioned Firebug takes advantage of dual processors it also no longer completely monopolizes the machine like you did on Mac OS 9 so if you want you can leave your other apps open now it's not doing anything but let me ask it to show cycle start back and you'll see that it gets quite busy this is a pretty fast g4 tower I have on a slower units maxed out both processors or one hundred percent running Firebug but you can see it is using them both so if you are longtime Firebug users you're tired of booting back in the mac OS 9 to run Firebug if you'd like some of these new features I think you'll be pretty happy with this let's go back to the slide ok so i renounced all these new tools by tool fire starter fw busy bus those all run on ohci so you can use them on any mac that we have today plus Firebug which still requires PCI links all of these tools require Mac OS 10 10 point two point five or later very important if you're familiar with Firebug you know how it works it touches the hardware directly all of these tools do that that's good and bad we displace all fire wire services when you run the tool we do it in a clean way if you have an ipod or a disc mounted the tool will refuse to run it won't just displace the driver and leave you with a corrupt ipod you will have to unplug any discs or iPods that you have in order to run these tools but because we displace the software you no longer have mac OS 10 on the bus trying to manage the bus so if you're trying to run five tool to figure out why some camcorder keeps resetting the bus you don't have to wonder if mac OS 10 is also on there trying to manage the bus if not we've displaced it the tool is the only thing touching the bus these are all new we've tested them as best we can but please be careful they do touch hardware directly so they can crash the machine make backups or run this on a dedicated machine at least until you're sure that it's really going to be stable in your environment and watch our mailing list for updates regarding these tools because again they're new so you're probably wondering where can I get all these great tools these sounds like I want to try them out today well you can firewire SDK 17 is available live today on the web the only catch is that because they redesigned the whole ADC website yesterday the link is missing I know you can all figure this out go find SDK 16 copy the link change the 62 or seven and you'll get to disk image for SDK 17 [Applause] okay let's wrap up here are the firewire sessions at double WC this week not including 505 which you're in right now tomorrow morning 50 for developing with firewire 800 that's the higher level session but we have a ton of new content this year about how firewire 800 works we have a feedback form for both firewire and USB like we do every year you can get all your serial bus feedback in one convenient location we have a new session this year on Thursday 508 the firewire reference platform will go into much greater detail about what's in there and how you can use it to make products finally thursday evening during the apple campus bash we have our firewire USB and bluetooth plug and unplug fest and i'm sure that will be very interesting if you'd like to contact apple if you want to come to a firewire kitchen if you need help developing you want license a reference platform here's contact information prashant con harry he'll be up here in a moment is the program manager for firewire technologies you can also contact your mo Ortiz and apple developer relations we have a public developer mailing list anybody can join us a lot of people on there this is a place where developers can ask questions developers can answer questions we answer questions too we announce new tools we announce things about Firebug just follow this link and you can subscribe at the same place you can subscribe to the reference platform mailing list which the same thing but it's focused on the reference platform if you'd like more information about developing firewire in Mac OS 10 our standard document is a book called working with firewire device interfaces I said earlier that's the formal name for a user client it's available online has a lot of information about how to use the user client to talk to firewire devices our software development kits are all available on the web ftk 17 as I just described we also have a tech note coming i don't think it's live yet that goes into more depths about how to use dcl it should be posted soon and we'll announce it on the mailing list when it is the I Triple E 1394 standard itself is available from the I Triple E on the way the 1394 ta also on the web has standards for a vc command sip the I IDC digital camera automotive 1394 various other interesting things and if you're working with ABC you may also need some standards from the ISO such as the format for DV video it's also available on the web