Re: PWM API
Thanks for your patience everyone. I went to write the PWM drivers for Arduino Zero and learned a lot that I wanted to share. 1) First, I agree that we should set duty cycle in fractional 16-bit. I experimented with it and found your observations correct. 2) Arduino (SAMD21G) has two different types of PWM hardware internally, TC and TCC. There is a key difference that will affect even this simple API. 3) The multichannel support is challenging to abstract in a Hal, so I suspect folks that need that will need a specific API for their control purpose (I.e. synchronous Steppers) The TC (when running in 16-bit mode) supports only the CC register (Capture). This allows us to set the duty cycle of the PWM waveform, the but period must be specified by the source CLOCK and a binary divide ratio. That means that setting of accurate frequency is not really possible (other than to a factor of 2-16 depending on your luck). For example, with an 8 Mhz clock driving the PWM, we get frequencies of 122 Hz (800/65536) for the PWM. I can increase the GCLK, but that seems to give flicker free operation and is the default config of the device. You can divide this down, but that produces geometrically lower frequencies. NOTE: when running in 8-bit mode, you can have control over both the CC and period values and we could get better freq control, but the resolution is quite poor. There’s another gotcha with the TC channels. Each TC drives two PWM channels, but there is only a single source clock (and a single period in 8-bit mode) for the two of them so two TC channels cannot set coarse frequency independently. This is evident on Arduino zero D10 and D12 (also A1 and A2) which run off the same TC. The TCC (when running in 16-bit mode) supports the CC and period register. This allows very fined grained control over the PWM frequency and duty cycle. There is one more catch which is the TCC supports 4 CC channels but only has one source clock and one Period register (Arduino D13 and D11 and also A3,A4,D9). Which brings me to the discussion here… Since there is only one source clock per TC or TCC device, I set the source clock divider in the BSP. This is the reasonable place to set this as its the place where you know what is routed where on your board and what freqs you want. The BSP also sets the source clock frequency. I created the following API,modifying my proposal taking the advice of the folks on this thread: struct hal_pwm* hal_pwm_init(enum system_device_id sysid); Int hal_pwm_off(struct hal_pwm *ppwm); Int hal_pwm_enable_duty_cycle(struct hal_pwm *ppwm, uint16_t fraction); Int hal_pwm_enable_waveform(struct hal_pwm *ppwm, uint32_t on_clocks); Int hal_pwm_get_clock_freq(struct hal_pwm *ppwm); Int hal_pwm_get_resolution_bits(struct hal_pwm *ppwm); NOTE: There are two different ways to enable the device. One based on duty cycle and another base on source clocks (exact). Someone on the thread suggested setting frequency and duty_cycle in a single Api, but some of the Arduino devices don’t support setting frequency (see above) and some do, so I though that the API would be better split. But, this brings up all the concerns with Greg and Will below, mainly “What if you had a separate API for frequency and duty etc)… My desire to make beeps that sound like donkey kong is too strong (go runtime), so I want to allow an API that sets the frequency. So based on the following assumptions, I will propose something new. 1) the BSP will set the frequency into the right ballpark since some controller don’t have fine grained frequency control 2) Aside from that, any super fine tuning of frequency is likely to be for audio control or other non duty cycle based operation 3) Anyone doing anything super fancy with these multi-channel controllers will likely use the direct hardware API or a future more complicated abstractions I propose to: 1) remove the hal_pwm_enable_waveform (which I wanted) accepting that the 16-bit duty cycle is plenty of fine-grained control Add one of the two following APIs with a note that they are not supported on all controllers. 1) hal_pwm_enable_freq(struct hal_pwm *ppwm, uint32_t freq_hz); ― set the frequency in Hz with 50 % duty cycle. 2) hal_pwm_enable_freq(struct hal_pwm *ppwm, uint32_t freq_hz, uint16_t duty); ― set the frequency in Hz and duty cycle as fractional 16-bit value; But either of these begs the question. 1) What if I set the frequency with either of these Apis and then call hal_pwm_enable_duty_cycle. Does it reset the frequency or just change the duty cycle? How do I restore the default frequency. Seems like I would have to do the former (reset the freq). My plan if I don’t hear better advice, will be to implement #1 and document that you can set frequency or duty cycle dynamically in the API but to both. #1. Paul On 3/31/16, 2:33 PM, "will sanfilippo" wrote: >Comments… > >> On Mar 31, 2016, at 1:59 AM, Greg Stein wrote: >> >> On Mar 30, 2016 11:48 PM
Re: Testing rhe libs/shell
Ok .I got it. Thanks On 4/5/16, Sterling Hughes wrote: > >> >> FROM: >> >> repository.apache-mynewt-core: >> type: github >> vers: 0-latest >> user: apache >> repo: incubator-mynewt-core >> >> TO: >> >> repository.apache-mynewt-core: >> type: github >> vers: 0.0.0 >> user: apache >> repo: incubator-mynewt-core >> >> Note that the develop branch my be broken at any time, so it is only >> recommended for testing and development. Also, it is likely to be >> incompatible with non-develop-branches of other repositories (e.g., newt >> tool and arduino repo). >> > > Also note, that 0-dev works. I added a tag for that the other day, for > remote projects that want to track dev. > > Sterling > -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record
Re: Testing rhe libs/shell
FROM: repository.apache-mynewt-core: type: github vers: 0-latest user: apache repo: incubator-mynewt-core TO: repository.apache-mynewt-core: type: github vers: 0.0.0 user: apache repo: incubator-mynewt-core Note that the develop branch my be broken at any time, so it is only recommended for testing and development. Also, it is likely to be incompatible with non-develop-branches of other repositories (e.g., newt tool and arduino repo). Also note, that 0-dev works. I added a tag for that the other day, for remote projects that want to track dev. Sterling
Re: Testing rhe libs/shell
On Mon, Apr 04, 2016 at 11:55:54PM +0100, Nges B wrote: > in a new created project , the newt test all fails the libs/json . > the jlibs/json was not corrected on that repository. > Thanks It looks like this particular fix was already pushed to the develop branch on 2016-03-21 (e8a365bd766ac2963ca9c757175889caf5f12461). The reason you still see the test failure in a newly created project is that newt's default behavior is to use the mynewt_0_8_0_b2_tag, not the develop branch. The json unit test fix will be visible by default in the next release of the core repository. If you want to try out the fix, you can configure your project to use the develop branch of core. Do this by changing your project.yml file to use core 0.0.0 as follows: FROM: repository.apache-mynewt-core: type: github vers: 0-latest user: apache repo: incubator-mynewt-core TO: repository.apache-mynewt-core: type: github vers: 0.0.0 user: apache repo: incubator-mynewt-core Note that the develop branch my be broken at any time, so it is only recommended for testing and development. Also, it is likely to be incompatible with non-develop-branches of other repositories (e.g., newt tool and arduino repo). Thanks for submitting the pull request. As this particular fix was already implemented, I will close the request, but please submit more if you find other issues Chris
Re: Testing rhe libs/shell
Nges, That unfortunately (or fortunately) will keep changing as the project evolves. So the right thing to do it to make it clear that it’s a snapshot at a certain point in time. I can make that clear. Thanks! aditi > On Apr 4, 2016, at 3:50 PM, Nges B wrote: > > you can do it. > also when you run tree in a newly created project, you have > 6directoies and 11filles not 10files as in DOcumentation :) > > On 4/4/16, Nges B wrote: >> But it seems to be magic :) >> I would I have love too but it seems more complicated that I taught. >> Thanks >> >> On 4/4/16, Aditi wrote: >>> Indeed. I can change that. Or you can generate a pull request on the >>> github >>> mirror if you want to test run the patch process for documentation. >>> >>> Thanks, >>> Aditi >>> >>> Sent from my iPhone >>> On Apr 4, 2016, at 2:15 PM, Nges B wrote: we can put something like 'newt test @apache-mynewt-core/libs/os' thanks > On 4/4/16, Nges B wrote: > Hi everyone. > There seems to be no test for libs/shell > > But in Documentation , tutorials for beginners give 'test newt test > @apache-mynewt-core/libs/shell' as an example. I think it will e > better if we can change it , It can confuse newbies. > Thanks > -- > "A Gal is a Dream with a Plan and a Dateline" > > Do On to Others what you will like them to do on to you.'The Golden > Rule' > Mozilla Regional Ambassador Lead Cameroon. > Software Deloper, > Web Designer and Developer. > Music DJ . Artiste at Casky Black's Record -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record >>> >> >> >> -- >> "A Gal is a Dream with a Plan and a Dateline" >> >> Do On to Others what you will like them to do on to you.'The Golden Rule' >> Mozilla Regional Ambassador Lead Cameroon. >> Software Deloper, >> Web Designer and Developer. >> Music DJ . Artiste at Casky Black's Record >> > > > -- > "A Gal is a Dream with a Plan and a Dateline" > > Do On to Others what you will like them to do on to you.'The Golden Rule' > Mozilla Regional Ambassador Lead Cameroon. > Software Deloper, > Web Designer and Developer. > Music DJ . Artiste at Casky Black's Record
Re: Testing rhe libs/shell
in a new created project , the newt test all fails the libs/json . the jlibs/json was not corrected on that repository. Thanks On 4/4/16, Nges B wrote: > you can do it. > also when you run tree in a newly created project, you have > 6directoies and 11filles not 10files as in DOcumentation :) > > On 4/4/16, Nges B wrote: >> But it seems to be magic :) >> I would I have love too but it seems more complicated that I taught. >> Thanks >> >> On 4/4/16, Aditi wrote: >>> Indeed. I can change that. Or you can generate a pull request on the >>> github >>> mirror if you want to test run the patch process for documentation. >>> >>> Thanks, >>> Aditi >>> >>> Sent from my iPhone >>> On Apr 4, 2016, at 2:15 PM, Nges B wrote: we can put something like 'newt test @apache-mynewt-core/libs/os' thanks > On 4/4/16, Nges B wrote: > Hi everyone. > There seems to be no test for libs/shell > > But in Documentation , tutorials for beginners give 'test newt test > @apache-mynewt-core/libs/shell' as an example. I think it will e > better if we can change it , It can confuse newbies. > Thanks > -- > "A Gal is a Dream with a Plan and a Dateline" > > Do On to Others what you will like them to do on to you.'The Golden > Rule' > Mozilla Regional Ambassador Lead Cameroon. > Software Deloper, > Web Designer and Developer. > Music DJ . Artiste at Casky Black's Record -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record >>> >> >> >> -- >> "A Gal is a Dream with a Plan and a Dateline" >> >> Do On to Others what you will like them to do on to you.'The Golden Rule' >> Mozilla Regional Ambassador Lead Cameroon. >> Software Deloper, >> Web Designer and Developer. >> Music DJ . Artiste at Casky Black's Record >> > > > -- > "A Gal is a Dream with a Plan and a Dateline" > > Do On to Others what you will like them to do on to you.'The Golden Rule' > Mozilla Regional Ambassador Lead Cameroon. > Software Deloper, > Web Designer and Developer. > Music DJ . Artiste at Casky Black's Record > -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record
Re: Testing rhe libs/shell
you can do it. also when you run tree in a newly created project, you have 6directoies and 11filles not 10files as in DOcumentation :) On 4/4/16, Nges B wrote: > But it seems to be magic :) > I would I have love too but it seems more complicated that I taught. > Thanks > > On 4/4/16, Aditi wrote: >> Indeed. I can change that. Or you can generate a pull request on the >> github >> mirror if you want to test run the patch process for documentation. >> >> Thanks, >> Aditi >> >> Sent from my iPhone >> >>> On Apr 4, 2016, at 2:15 PM, Nges B wrote: >>> >>> we can put something like 'newt test @apache-mynewt-core/libs/os' >>> thanks >>> >>> On 4/4/16, Nges B wrote: Hi everyone. There seems to be no test for libs/shell But in Documentation , tutorials for beginners give 'test newt test @apache-mynewt-core/libs/shell' as an example. I think it will e better if we can change it , It can confuse newbies. Thanks -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record >>> >>> >>> -- >>> "A Gal is a Dream with a Plan and a Dateline" >>> >>> Do On to Others what you will like them to do on to you.'The Golden >>> Rule' >>> Mozilla Regional Ambassador Lead Cameroon. >>> Software Deloper, >>> Web Designer and Developer. >>> Music DJ . Artiste at Casky Black's Record >> > > > -- > "A Gal is a Dream with a Plan and a Dateline" > > Do On to Others what you will like them to do on to you.'The Golden Rule' > Mozilla Regional Ambassador Lead Cameroon. > Software Deloper, > Web Designer and Developer. > Music DJ . Artiste at Casky Black's Record > -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record
Re: Testing rhe libs/shell
But it seems to be magic :) I would I have love too but it seems more complicated that I taught. Thanks On 4/4/16, Aditi wrote: > Indeed. I can change that. Or you can generate a pull request on the github > mirror if you want to test run the patch process for documentation. > > Thanks, > Aditi > > Sent from my iPhone > >> On Apr 4, 2016, at 2:15 PM, Nges B wrote: >> >> we can put something like 'newt test @apache-mynewt-core/libs/os' >> thanks >> >> >>> On 4/4/16, Nges B wrote: >>> Hi everyone. >>> There seems to be no test for libs/shell >>> >>> But in Documentation , tutorials for beginners give 'test newt test >>> @apache-mynewt-core/libs/shell' as an example. I think it will e >>> better if we can change it , It can confuse newbies. >>> Thanks >>> -- >>> "A Gal is a Dream with a Plan and a Dateline" >>> >>> Do On to Others what you will like them to do on to you.'The Golden >>> Rule' >>> Mozilla Regional Ambassador Lead Cameroon. >>> Software Deloper, >>> Web Designer and Developer. >>> Music DJ . Artiste at Casky Black's Record >> >> >> -- >> "A Gal is a Dream with a Plan and a Dateline" >> >> Do On to Others what you will like them to do on to you.'The Golden Rule' >> Mozilla Regional Ambassador Lead Cameroon. >> Software Deloper, >> Web Designer and Developer. >> Music DJ . Artiste at Casky Black's Record > -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record
Re: Image signatures
EC operations would be significantly smaller. They key size equivalent to RSA 2048 but would be 256 bits in EC. So that could be another option. Thanks, Aditi Sent from my iPhone > On Apr 4, 2016, at 12:49 PM, marko kiiskila wrote: > > Hi, > > I started work on signed images, and there’s few things I’m wondering how to > go about. > > The way this would work is that you would start by creating a RSA key-pair > (2048 bits). > > You’d sign the image by computing RSA signature over the image hash (SHA256), > and store > it a TLV at the end of the image. Bootloader would be built with the public > key of this > image signing key, and it would verify it before allowing the image to boot. > > The impact of this on the bootloader is ~7k of additional text, so it’s use > should be optional. > That comes from code to parse the public key and RSA itself. And the public > key itself. > > The image header contains a flag that says that this image contains this kind > of signature, > as well as the total length of all TLVs in the end. Image hash is computed > over this header. > > Signature data itself is stored in PKCS 1.5 format. > > I also added a keyid field, and you can use this to facilitate the use of > multiple image signing > keys. You could use this to facilitate the use of image signing keys of > different security > level. I.e. you would have a separate image signing key for building > ‘production’ builds as > opposed to ‘development’ builds. > > Production signing key would be stored somewhere safe with controlled access, > while > development key could have more lax restrictions. Then you’d have different > bootloader > versions, dev boot loaders would allow it to boot images that are signed with > production keys, > or with development keys. Production boot loaders would only allow it to boot > images signed > with production keys only. > > This way you can do in-house development/QA using images signed with dev > keys, without > having to worry about those images being bootable by products in the field. > > On to my questions: > 1) Any reviews of this code would be much appreciated! Bugs in this code > would be (very) bad. > 2) How should this be incorporated into build system? Specifically, how to > control > - whether bootloader expects signed images, and if so, whether it’s a dev > bootloader, or > production bootloader? > - where should the public key for bootloader be stored? Note that this > probably would be > per-product specific. > > Comments, suggestions are welcome
Re: Testing rhe libs/shell
Indeed. I can change that. Or you can generate a pull request on the github mirror if you want to test run the patch process for documentation. Thanks, Aditi Sent from my iPhone > On Apr 4, 2016, at 2:15 PM, Nges B wrote: > > we can put something like 'newt test @apache-mynewt-core/libs/os' > thanks > > >> On 4/4/16, Nges B wrote: >> Hi everyone. >> There seems to be no test for libs/shell >> >> But in Documentation , tutorials for beginners give 'test newt test >> @apache-mynewt-core/libs/shell' as an example. I think it will e >> better if we can change it , It can confuse newbies. >> Thanks >> -- >> "A Gal is a Dream with a Plan and a Dateline" >> >> Do On to Others what you will like them to do on to you.'The Golden Rule' >> Mozilla Regional Ambassador Lead Cameroon. >> Software Deloper, >> Web Designer and Developer. >> Music DJ . Artiste at Casky Black's Record > > > -- > "A Gal is a Dream with a Plan and a Dateline" > > Do On to Others what you will like them to do on to you.'The Golden Rule' > Mozilla Regional Ambassador Lead Cameroon. > Software Deloper, > Web Designer and Developer. > Music DJ . Artiste at Casky Black's Record
Re: Image signatures
> On Apr 4, 2016, at 12:49 PM, marko kiiskila wrote: > > Hi, > > I started work on signed images, and there’s few things I’m wondering how to > go about. > > The way this would work is that you would start by creating a RSA key-pair > (2048 bits). > > You’d sign the image by computing RSA signature over the image hash (SHA256), > and store > it a TLV at the end of the image. Bootloader would be built with the public > key of this > image signing key, and it would verify it before allowing the image to boot. > > The impact of this on the bootloader is ~7k of additional text, so it’s use > should be optional. > That comes from code to parse the public key and RSA itself. And the public > key itself. > > The image header contains a flag that says that this image contains this kind > of signature, > as well as the total length of all TLVs in the end. Image hash is computed > over this header. > > Signature data itself is stored in PKCS 1.5 format. > > I also added a keyid field, and you can use this to facilitate the use of > multiple image signing > keys. You could use this to facilitate the use of image signing keys of > different security > level. I.e. you would have a separate image signing key for building > ‘production’ builds as > opposed to ‘development’ builds. > > Production signing key would be stored somewhere safe with controlled access, > while > development key could have more lax restrictions. Then you’d have different > bootloader > versions, dev boot loaders would allow it to boot images that are signed with > production keys, > or with development keys. Production boot loaders would only allow it to boot > images signed > with production keys only. > > This way you can do in-house development/QA using images signed with dev > keys, without > having to worry about those images being bootable by products in the field. > > On to my questions: > 1) Any reviews of this code would be much appreciated! Bugs in this code > would be (very) bad. > 2) How should this be incorporated into build system? Specifically, how to > control > - whether bootloader expects signed images, and if so, whether it’s a dev > bootloader, or > production bootloader? > - where should the public key for bootloader be stored? Note that this > probably would be > per-product specific. E.g. we could store public key(s) in a package which exports 2 symbols: pointer to array of keys, and the number of elements in that given array. It would export feature ‘IMAGE_KEYS’. Then, if you’re building a bootloader with such a package included, then image signatures are required. This way user could check this in, and manage it’s inclusion in the bootloader any which they want. I.e. could depend on the target, BSP, app or any other.
Re: Testing rhe libs/shell
we can put something like 'newt test @apache-mynewt-core/libs/os' thanks On 4/4/16, Nges B wrote: > Hi everyone. > There seems to be no test for libs/shell > > But in Documentation , tutorials for beginners give 'test newt test > @apache-mynewt-core/libs/shell' as an example. I think it will e > better if we can change it , It can confuse newbies. > Thanks > -- > "A Gal is a Dream with a Plan and a Dateline" > > Do On to Others what you will like them to do on to you.'The Golden Rule' > Mozilla Regional Ambassador Lead Cameroon. > Software Deloper, > Web Designer and Developer. > Music DJ . Artiste at Casky Black's Record > -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record
Testing rhe libs/shell
Hi everyone. There seems to be no test for libs/shell But in Documentation , tutorials for beginners give 'test newt test @apache-mynewt-core/libs/shell' as an example. I think it will e better if we can change it , It can confuse newbies. Thanks -- "A Gal is a Dream with a Plan and a Dateline" Do On to Others what you will like them to do on to you.'The Golden Rule' Mozilla Regional Ambassador Lead Cameroon. Software Deloper, Web Designer and Developer. Music DJ . Artiste at Casky Black's Record
Image signatures
Hi, I started work on signed images, and there’s few things I’m wondering how to go about. The way this would work is that you would start by creating a RSA key-pair (2048 bits). You’d sign the image by computing RSA signature over the image hash (SHA256), and store it a TLV at the end of the image. Bootloader would be built with the public key of this image signing key, and it would verify it before allowing the image to boot. The impact of this on the bootloader is ~7k of additional text, so it’s use should be optional. That comes from code to parse the public key and RSA itself. And the public key itself. The image header contains a flag that says that this image contains this kind of signature, as well as the total length of all TLVs in the end. Image hash is computed over this header. Signature data itself is stored in PKCS 1.5 format. I also added a keyid field, and you can use this to facilitate the use of multiple image signing keys. You could use this to facilitate the use of image signing keys of different security level. I.e. you would have a separate image signing key for building ‘production’ builds as opposed to ‘development’ builds. Production signing key would be stored somewhere safe with controlled access, while development key could have more lax restrictions. Then you’d have different bootloader versions, dev boot loaders would allow it to boot images that are signed with production keys, or with development keys. Production boot loaders would only allow it to boot images signed with production keys only. This way you can do in-house development/QA using images signed with dev keys, without having to worry about those images being bootable by products in the field. On to my questions: 1) Any reviews of this code would be much appreciated! Bugs in this code would be (very) bad. 2) How should this be incorporated into build system? Specifically, how to control - whether bootloader expects signed images, and if so, whether it’s a dev bootloader, or production bootloader? - where should the public key for bootloader be stored? Note that this probably would be per-product specific. Comments, suggestions are welcome
Re: os_eventq_get() + timeout
+1 for option#2 and Sterlings implementation. Next request by someone might be to have a timeout per eventq. > On Apr 4, 2016, at 12:09 PM, Sterling Hughes wrote: > > hi, > > On 4/4/16 11:59 AM, marko kiiskila wrote: >> >>> On Apr 4, 2016, at 11:33 AM, Sterling Hughes wrote: >>> I don’t think the select() kind of mask is a good idea. eventq_XXX is more like kqueue() rather than select(). I don’t think there are that many places where you’d want to mask out some events and not others. Especially as this’ll mean that there will presumably will mean that events will get delivered out of order. >>> >>> Would you prefer that eventq_poll() poll multiple eventq and return when an >>> event is available on one of them, or there is a timeout? I can >>> understand wanting to preserve ordering on the queue, and things getting >>> confusing if app code isn't smart about this. >>> >>> However, I think it is a fairly common access mechanism to want to grab >>> only certain events from a queue. Imagine a case where you send a packet, >>> and you are waiting for a response, and you only want to pull events >>> related to response from the eventq, even if you have multiple events that >>> can run through that queue. I see two options for handling this neatly: >>> >>> 1- Have a mask, and only pull events off that queue which match the mask >>> 2- Have eventq_poll() take multiple event queues, so that you can poll >>> multiple queues at once. >>> >>> What do you think? >>> >> >> Converting an array of integers to bit mask in the caller, and doing the >> reverse >> in the callee is not too great. >> >> Option 2 sounds much, much better. >> > > OK, cool. > > So, this is the API I'm thinking of: > > struct os_event * > os_eventq_poll(struct os_eventq **evq, int n, os_time_t timo); > > Where evq is an array of eventq to poll, and n is the number of elements in > that array. timo represents the timeout in ticks, across all the eventqs. > > This function returns NULL on no events within timo, or the first available > event if not. timo can be OS_WAIT_FOREVER, if caller wishes to sleep until > an event becomes available. > > Sterling
Re: os_eventq_get() + timeout
> On Apr 4, 2016, at 12:09 PM, Sterling Hughes wrote: > > hi, > > On 4/4/16 11:59 AM, marko kiiskila wrote: >> >>> On Apr 4, 2016, at 11:33 AM, Sterling Hughes wrote: >>> I don’t think the select() kind of mask is a good idea. eventq_XXX is more like kqueue() rather than select(). I don’t think there are that many places where you’d want to mask out some events and not others. Especially as this’ll mean that there will presumably will mean that events will get delivered out of order. >>> >>> Would you prefer that eventq_poll() poll multiple eventq and return when an >>> event is available on one of them, or there is a timeout? I can >>> understand wanting to preserve ordering on the queue, and things getting >>> confusing if app code isn't smart about this. >>> >>> However, I think it is a fairly common access mechanism to want to grab >>> only certain events from a queue. Imagine a case where you send a packet, >>> and you are waiting for a response, and you only want to pull events >>> related to response from the eventq, even if you have multiple events that >>> can run through that queue. I see two options for handling this neatly: >>> >>> 1- Have a mask, and only pull events off that queue which match the mask >>> 2- Have eventq_poll() take multiple event queues, so that you can poll >>> multiple queues at once. >>> >>> What do you think? >>> >> >> Converting an array of integers to bit mask in the caller, and doing the >> reverse >> in the callee is not too great. >> >> Option 2 sounds much, much better. >> > > OK, cool. > > So, this is the API I'm thinking of: > > struct os_event * > os_eventq_poll(struct os_eventq **evq, int n, os_time_t timo); > > Where evq is an array of eventq to poll, and n is the number of elements in > that array. timo represents the timeout in ticks, across all the eventqs. > > This function returns NULL on no events within timo, or the first available > event if not. timo can be OS_WAIT_FOREVER, if caller wishes to sleep until > an event becomes available. > > Sterling +1
flash circular buffer
Hi, I implemented this and want to know what you guys think of the interface. FCB is a facility that allows you to store blobs of data in flash a bit like a FIFO. You always append things in the end, and you start reading things from beginning. This is to be used when you want to e.g. keep a log of events and have them persist over a system reset. Data always gets added in the end; you would start by calling fcb_append() with the amount of data you’ll want to add. That function reserves space in the flash, and would return you info about where in the flash data would be. After that, you would write the data element to that location, and finish by calling fcb_append_finish(). This function finalizes the write by computing a checksum over the data, and appending the checkup to the end. That is how user is protected against partial writes (system reset before all data gets in). For inspecting the data in flash, there’s 2 options: either fcb_walk(), or fcb_getnext(). fcb_walk() walks over the data elements in the flash, calling user specified callback for every (completed) element it encounters. If you want to stop the walk, you can tell it using non-zero return code from your callback. fcb_getnext() can be used similarly to fcb_walk(), it takes as a parameter the location of previous element, and gives you in return the location of next element in the circular buffer. Flash sectors fill up eventually. The way you’d deal with this is by erasing data a sector at a time, calling fcb_rotate() erases the data in the oldest sector you’ve been using. So for a rolling log you would keep appending data until you can fit no more, then erase the oldest one and add some more. For places where you download/upload the data periodically, you would erase the sector once data from it has been stored somewhere safe. Any comments, suggestions? — M
Re: os_eventq_get() + timeout
hi, On 4/4/16 11:59 AM, marko kiiskila wrote: On Apr 4, 2016, at 11:33 AM, Sterling Hughes wrote: I don’t think the select() kind of mask is a good idea. eventq_XXX is more like kqueue() rather than select(). I don’t think there are that many places where you’d want to mask out some events and not others. Especially as this’ll mean that there will presumably will mean that events will get delivered out of order. Would you prefer that eventq_poll() poll multiple eventq and return when an event is available on one of them, or there is a timeout? I can understand wanting to preserve ordering on the queue, and things getting confusing if app code isn't smart about this. However, I think it is a fairly common access mechanism to want to grab only certain events from a queue. Imagine a case where you send a packet, and you are waiting for a response, and you only want to pull events related to response from the eventq, even if you have multiple events that can run through that queue. I see two options for handling this neatly: 1- Have a mask, and only pull events off that queue which match the mask 2- Have eventq_poll() take multiple event queues, so that you can poll multiple queues at once. What do you think? Converting an array of integers to bit mask in the caller, and doing the reverse in the callee is not too great. Option 2 sounds much, much better. OK, cool. So, this is the API I'm thinking of: struct os_event * os_eventq_poll(struct os_eventq **evq, int n, os_time_t timo); Where evq is an array of eventq to poll, and n is the number of elements in that array. timo represents the timeout in ticks, across all the eventqs. This function returns NULL on no events within timo, or the first available event if not. timo can be OS_WAIT_FOREVER, if caller wishes to sleep until an event becomes available. Sterling
Re: os_eventq_get() + timeout
> On Apr 4, 2016, at 11:33 AM, Sterling Hughes wrote: > >> I don’t think the select() kind of mask is a good idea. eventq_XXX is more >> like kqueue() rather than select(). I don’t think there are that many places >> where you’d want to mask out some events and not others. Especially >> as this’ll mean that there will presumably will mean that events will get >> delivered out of order. >> > > Would you prefer that eventq_poll() poll multiple eventq and return when an > event is available on one of them, or there is a timeout? I can understand > wanting to preserve ordering on the queue, and things getting confusing if > app code isn't smart about this. > > However, I think it is a fairly common access mechanism to want to grab only > certain events from a queue. Imagine a case where you send a packet, and you > are waiting for a response, and you only want to pull events related to > response from the eventq, even if you have multiple events that can run > through that queue. I see two options for handling this neatly: > > 1- Have a mask, and only pull events off that queue which match the mask > 2- Have eventq_poll() take multiple event queues, so that you can poll > multiple queues at once. > > What do you think? > Converting an array of integers to bit mask in the caller, and doing the reverse in the callee is not too great. Option 2 sounds much, much better.
Newt package, package search & new
Heya,
I'm going to put a little work into newt, and how we compose projects
with it. I think there are a couple of areas where I think we could
improve:
1- "newt new" currently fetches
github.com/apache/incubator-mynewt-blinky as a project skeleton. I
think there should be configurable skeletons, and the default
(incubator-mynewt-blinky) should come bundled with the go src, so that
you don't need internet access to create a new project skeleton.
This should make newt general purpose enough to use with any project,
not just our OS. While primarily useful for our OS at the moment, I
think we want newt to stand on its own as a build & package management
tool for embedded contexts.
2- To newt install -v, you should be able to specify a local directory
that contains the necessary remote repositories, so if you want to
install the new project skeleton without internet access, you can.
3- We should add a new command: newt pkg new, which can create a new
package in the local repository, I'm thinking the format should be:
$ newt pkg new drivers/rgbled
Which will create a new package in /drivers/rgbled, along
with the pkg.yml file and src and include headers. Additional options to
this command should be a package type (default is lib), and the skeleton
will change depending on what type is specified (e.g. bsp, or app.)
4- Package search directories. Currently, there is a hardcoded set of
package search directories in the base of the project, specifically:
var PackageSearchDirs []string = []string{
"apps/",
"compiler/",
"fs/",
"libs/",
"net/",
"hw/bsp/",
"hw/mcu/",
"hw/mcu/stm",
"hw/drivers/",^[[>1;95;0c
"hw/",
"project/",
"targets/",
"sys/",
}
And then additional package directories can be specified by adding them
to the project.pkg_dirs configuration variable in project.yml.
We could have newt pkg new automatically add non-standard directories to
project.pkg_dirs, but it occurs to me that we may be too restrictive on
this for no reason. The base of our core repository is as follows:
total 88
-rw-r--r-- 1 sterling staff531 Apr 1 17:46 DISCLAIMER
-rw-r--r-- 1 sterling staff 16360 Apr 1 17:46 LICENSE
-rw-r--r-- 1 sterling staff254 Apr 1 17:46 NOTICE
-rw-r--r-- 1 sterling staff 9703 Apr 1 17:46 README.md
-rw-r--r-- 1 sterling staff 1713 Apr 1 17:46 RELEASE_NOTES.md
drwxr-xr-x 11 sterling staff374 Apr 1 17:46 apps
drwxr-xr-x 5 sterling staff170 Apr 1 17:46 compiler
drwxr-xr-x 4 sterling staff136 Apr 1 17:46 fs
drwxr-xr-x 5 sterling staff170 Apr 1 17:46 hw
drwxr-xr-x 17 sterling staff578 Apr 1 17:46 libs
drwxr-xr-x 3 sterling staff102 Apr 1 17:46 net
-rw-r--r-- 1 sterling staff825 Apr 1 17:46 project.yml
drwxr-xr-x 6 sterling staff204 Apr 1 17:46 sys
drwxr-xr-x 3 sterling staff102 Apr 1 17:46 targets
As you can see, every directory here contains packages in them. I think
it would be better to, by default, search all directories for packages,
and provide a configuration directive to ignore directories.
Thoughts?
Cheers,
Sterling
Re: os_eventq_get() + timeout
On 4/4/16 10:50 AM, marko kiiskila wrote: Hi, You get the timeout functionality by adding an timeout event on your own to get the same functionality. Would not be a big burden. However, this kind of convenience function should be ok. You could even have that guy implement it this way, as opposed to adding additional code to eventq_get() itself. Yeah, I think many people want to use this. I don’t think the select() kind of mask is a good idea. eventq_XXX is more like kqueue() rather than select(). I don’t think there are that many places where you’d want to mask out some events and not others. Especially as this’ll mean that there will presumably will mean that events will get delivered out of order. Would you prefer that eventq_poll() poll multiple eventq and return when an event is available on one of them, or there is a timeout? I can understand wanting to preserve ordering on the queue, and things getting confusing if app code isn't smart about this. However, I think it is a fairly common access mechanism to want to grab only certain events from a queue. Imagine a case where you send a packet, and you are waiting for a response, and you only want to pull events related to response from the eventq, even if you have multiple events that can run through that queue. I see two options for handling this neatly: 1- Have a mask, and only pull events off that queue which match the mask 2- Have eventq_poll() take multiple event queues, so that you can poll multiple queues at once. What do you think? Sterling
Re: os_eventq_get() + timeout
Hi,
You get the timeout functionality by adding an timeout event on your own
to get the same functionality. Would not be a big burden.
However, this kind of convenience function should be ok. You could
even have that guy implement it this way, as opposed to adding additional
code to eventq_get() itself.
I don’t think the select() kind of mask is a good idea. eventq_XXX is more
like kqueue() rather than select(). I don’t think there are that many places
where you’d want to mask out some events and not others. Especially
as this’ll mean that there will presumably will mean that events will get
delivered out of order.
> On Apr 4, 2016, at 9:13 AM, will sanfilippo wrote:
>
> I would not break BC; I would add a different function. Not sure what I would
> call it but wouldnt it just have a timeout, in ticks, associated with it? For
> example: os_eventq_wait(&my_evq, timeout_in_os_ticks). What is the purpose of
> the mask btw? Something to do with returning an error if it times out or some
> way of selecting particular events?
>
> Will
>
>> On Apr 4, 2016, at 8:14 AM, Sterling Hughes wrote:
>>
>> Hey,
>>
>> I'm looking at: https://issues.apache.org/jira/browse/MYNEWT-8
>>
>> I'm wondering if I should break BC on this one, and add a new parameter, or
>> add a new function call:
>>
>> - os_eventq_select()
>>
>> OS_EVENTQ_MASK(my_mask, EVENT_T_TIMER);
>> OS_EVENTQ_MASK(my_mask, EVENT_T_DATA);
>>
>> /* timeout after 200 ticks */
>> ev = os_eventq_select(&my_evq, &my_mask, 200);
>>
>> Thoughts?
>>
>> Sterling
>>
>> PS: For the uninitiated, os_eventq_get() works as follows.
>>
>> In your task, you create an eventq with os_eventq_init(), and then you wait
>> (forever) on os_eventq_get().
>>
>> If you (currently) want to not wait forever, you can use a callout, which
>> will post an event to the eventq after a certain time expires.
>>
>> while (1) {
>> ev = os_eventq_get(&my_evq);
>> switch (ev->ev_type) {
>> case EVENT_T_DATA: /* read data from socket */
>>recv_data();
>> case EVENT_T_TIMER: /* timer expired */
>>os_callout_reset(&my_callout, &my_evq, 20);
>> }
>> }
>
Re: os_eventq_get() + timeout
Sounds good to me +1 > On Apr 4, 2016, at 9:16 AM, Sterling Hughes > wrote: > > > >> On Apr 4, 2016, at 9:13 AM, will sanfilippo wrote: >> >> I would not break BC; I would add a different function. Not sure what I >> would call it but wouldnt it just have a timeout, in ticks, associated with >> it? For example: os_eventq_wait(&my_evq, timeout_in_os_ticks). What is the >> purpose of the mask btw? Something to do with returning an error if it times >> out or some way of selecting particular events? > > Right, it would allow you to quickly poll for a set/type of events. Select > is a common UNIX call which does the same thing (the other being poll()). > > I think it's useful to search the queue for a type of event, so if we're > adding a new call with timeout, I think we should add that functionality. > > Sterling
Re: os_eventq_get() + timeout
> On Apr 4, 2016, at 9:13 AM, will sanfilippo wrote: > > I would not break BC; I would add a different function. Not sure what I would > call it but wouldnt it just have a timeout, in ticks, associated with it? For > example: os_eventq_wait(&my_evq, timeout_in_os_ticks). What is the purpose of > the mask btw? Something to do with returning an error if it times out or some > way of selecting particular events? Right, it would allow you to quickly poll for a set/type of events. Select is a common UNIX call which does the same thing (the other being poll()). I think it's useful to search the queue for a type of event, so if we're adding a new call with timeout, I think we should add that functionality. Sterling
Re: os_eventq_get() + timeout
I would not break BC; I would add a different function. Not sure what I would
call it but wouldnt it just have a timeout, in ticks, associated with it? For
example: os_eventq_wait(&my_evq, timeout_in_os_ticks). What is the purpose of
the mask btw? Something to do with returning an error if it times out or some
way of selecting particular events?
Will
> On Apr 4, 2016, at 8:14 AM, Sterling Hughes wrote:
>
> Hey,
>
> I'm looking at: https://issues.apache.org/jira/browse/MYNEWT-8
>
> I'm wondering if I should break BC on this one, and add a new parameter, or
> add a new function call:
>
> - os_eventq_select()
>
> OS_EVENTQ_MASK(my_mask, EVENT_T_TIMER);
> OS_EVENTQ_MASK(my_mask, EVENT_T_DATA);
>
> /* timeout after 200 ticks */
> ev = os_eventq_select(&my_evq, &my_mask, 200);
>
> Thoughts?
>
> Sterling
>
> PS: For the uninitiated, os_eventq_get() works as follows.
>
> In your task, you create an eventq with os_eventq_init(), and then you wait
> (forever) on os_eventq_get().
>
> If you (currently) want to not wait forever, you can use a callout, which
> will post an event to the eventq after a certain time expires.
>
> while (1) {
>ev = os_eventq_get(&my_evq);
>switch (ev->ev_type) {
>case EVENT_T_DATA: /* read data from socket */
> recv_data();
>case EVENT_T_TIMER: /* timer expired */
> os_callout_reset(&my_callout, &my_evq, 20);
>}
> }
os_eventq_get() + timeout
Hey,
I'm looking at: https://issues.apache.org/jira/browse/MYNEWT-8
I'm wondering if I should break BC on this one, and add a new parameter,
or add a new function call:
- os_eventq_select()
OS_EVENTQ_MASK(my_mask, EVENT_T_TIMER);
OS_EVENTQ_MASK(my_mask, EVENT_T_DATA);
/* timeout after 200 ticks */
ev = os_eventq_select(&my_evq, &my_mask, 200);
Thoughts?
Sterling
PS: For the uninitiated, os_eventq_get() works as follows.
In your task, you create an eventq with os_eventq_init(), and then you
wait (forever) on os_eventq_get().
If you (currently) want to not wait forever, you can use a callout,
which will post an event to the eventq after a certain time expires.
while (1) {
ev = os_eventq_get(&my_evq);
switch (ev->ev_type) {
case EVENT_T_DATA: /* read data from socket */
recv_data();
case EVENT_T_TIMER: /* timer expired */
os_callout_reset(&my_callout, &my_evq, 20);
}
}
