• Re: AM623 experiences

    From David Brown@21:1/5 to Don Y on Sat Nov 23 13:31:28 2024
    On 23/11/2024 09:15, Don Y wrote:
    I'm looking to move my design onto said platform.

    Any first-hand experiences to share?

    Bugs in silicon, toolchain, support, etc.?


    I've no experience with that device at all, but from experience with
    other toolchains provided by TI over the years, watch out for zero initialisation of variables in the bss. TI have had this crazy idea
    that zero initialisation of program lifetime data is a waste of time at startup, so many of their toolchains don't do so unless you specifically
    add extra flags or extra code for it. This applied even to gcc-based toolchains. (You can achieve this non-standard behaviour by special
    linker scripts or a broken startup library.)

    Maybe they have stopped this lunacy, but I'd double-check this when
    using any toolchain supplied by TI for the M4 core. (The Linux cores - assuming you are using Linux on the A53's - will of course be standard.)



    Is there any particular reason for picking this device? AFAIK the NXP
    i.mx families are a lot more common for embedded Linux SoC's for
    industrial equipment.

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  • From Grant Edwards@21:1/5 to David Brown on Sat Nov 23 19:57:50 2024
    On 2024-11-23, David Brown <david.brown@hesbynett.no> wrote:
    On 23/11/2024 09:15, Don Y wrote:
    I'm looking to move my design onto said platform.

    Any first-hand experiences to share?

    Bugs in silicon, toolchain, support, etc.?


    I've no experience with that device at all, but from experience with
    other toolchains provided by TI over the years, watch out for zero initialisation of variables in the bss.

    For the cortex M4, I'd avoid using TI's toolchain if at all possible.
    Download a copy of GCC from ARM.

    The general rule I've found to be true for the past 40 years is that software/tools supplied by silicon vendors is crap.

    --
    Grant

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  • From Don Y@21:1/5 to Grant Edwards on Sat Nov 23 16:56:45 2024
    On 11/23/2024 12:57 PM, Grant Edwards wrote:
    On 2024-11-23, David Brown <david.brown@hesbynett.no> wrote:
    On 23/11/2024 09:15, Don Y wrote:
    I'm looking to move my design onto said platform.

    Any first-hand experiences to share?

    Bugs in silicon, toolchain, support, etc.?

    I've no experience with that device at all, but from experience with
    other toolchains provided by TI over the years, watch out for zero
    initialisation of variables in the bss.

    [Hmmm... I don't see your post, David. <frown> Something must be
    hosed in my server. (actually, I don't see MANY posts, here! Quiet?)]

    BSS is a good warning. I've been using other tools with the ARM that
    I've "abandoned" ("moved past" might be a kinder way of reference).

    I tend to rely on vendors tools *if* there is likely to be some
    bug that the tools can workaround -- that a third-party vendor
    may not be aware of (or address).

    For the cortex M4, I'd avoid using TI's toolchain if at all possible. Download a copy of GCC from ARM.

    This is an A53 (ARMv8) -- at least the "main cores" are. There's
    also an M4(F) -- and, as typical of ARM, a couple of other
    "specialty processors".

    The general rule I've found to be true for the past 40 years is that software/tools supplied by silicon vendors is crap.

    That's a direct analog of the issues with "sample applications" for
    hardware devices!

    What about "support"? Are there anything other than trained monkeys
    available? Or, is everything "forum based" (what a great scam!
    outsource your support to your CUSTOMERS!!)

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Brown@21:1/5 to Don Y on Sun Nov 24 11:42:43 2024
    On 24/11/2024 00:56, Don Y wrote:
    On 11/23/2024 12:57 PM, Grant Edwards wrote:
    On 2024-11-23, David Brown <david.brown@hesbynett.no> wrote:
    On 23/11/2024 09:15, Don Y wrote:
    I'm looking to move my design onto said platform.

    Any first-hand experiences to share?

    Bugs in silicon, toolchain, support, etc.?

    I've no experience with that device at all, but from experience with
    other toolchains provided by TI over the years, watch out for zero
    initialisation of variables in the bss.

    [Hmmm... I don't see your post, David.  <frown>  Something must be
    hosed in my server.  (actually, I don't see MANY posts, here!  Quiet?)]


    I don't think there is anything odd with my posting or the server on my
    side (eternal-september). But Grant quoted the most important part of
    my post - the rest was more venting than informative!

    It /is/ quiet in this newsgroup.

    BSS is a good warning.  I've been using other tools with the ARM that
    I've "abandoned" ("moved past" might be a kinder way of reference).

    I tend to rely on vendors tools *if* there is likely to be some
    bug that the tools can workaround -- that a third-party vendor
    may not be aware of (or address).


    ARM is pretty good at making sure they cover all known bugs - so their
    gcc toolchain builds tend to have backported patches that are not in the mainstream gcc source tree until a version or two later. Mistakes can
    happen, of course, and you can look at the issue trackers for their
    toolchain builds to see some of them. But for the kind of cores in
    question here, the microcontroller vendors have little influence over
    the cores themselves, and therefore less scope of introducing
    vendor-specific bugs.

    For the cortex M4, I'd avoid using TI's toolchain if at all possible.
    Download a copy of GCC from ARM.

    This is an A53 (ARMv8) -- at least the "main cores" are.  There's
    also an M4(F) -- and, as typical of ARM, a couple of other
    "specialty processors".

    The general rule I've found to be true for the past 40 years is that
    software/tools supplied by silicon vendors is crap.

    That's a direct analog of the issues with "sample applications" for
    hardware devices!

    What about "support"?  Are there anything other than trained monkeys available?  Or, is everything "forum based" (what a great scam!
    outsource your support to your CUSTOMERS!!)


    It is not uncommon for vendor employees to take part in these forums
    too. It is not actually a bad idea, because it means that when they
    answer a customer's question, the answer is available for anyone else
    doing a search.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Brown@21:1/5 to Grant Edwards on Sun Nov 24 11:33:37 2024
    On 23/11/2024 20:57, Grant Edwards wrote:
    On 2024-11-23, David Brown <david.brown@hesbynett.no> wrote:
    On 23/11/2024 09:15, Don Y wrote:
    I'm looking to move my design onto said platform.

    Any first-hand experiences to share?

    Bugs in silicon, toolchain, support, etc.?


    I've no experience with that device at all, but from experience with
    other toolchains provided by TI over the years, watch out for zero
    initialisation of variables in the bss.

    For the cortex M4, I'd avoid using TI's toolchain if at all possible. Download a copy of GCC from ARM.

    The general rule I've found to be true for the past 40 years is that software/tools supplied by silicon vendors is crap.


    Some vendor-supplied toolchains are not bad, but some are definitely
    subpar - and often many years behind the versions you get from
    manufacturer independent suppliers (like ARM's build of a gcc toolchain,
    or commercial gcc toolchains). The biggest problem with microcontroller manufacturer's tools is usually the SDK's that are frequently horrible
    in all sorts of ways.

    But I agree with your advice - where possible, use ARM's gcc toolchain
    build for ARM development. And make sure your project build is
    independent of any IDE, whether it is from the vendor or independent.
    IDE's are great for coding, and vendor-supplied IDE's can give good
    debugging tools, but you want the project build itself to be independent.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Grant Edwards@21:1/5 to David Brown on Sun Nov 24 17:12:10 2024
    On 2024-11-24, David Brown <david.brown@hesbynett.no> wrote:

    Some vendor-supplied toolchains are not bad, but some are definitely
    subpar - and often many years behind the versions you get from
    manufacturer independent suppliers (like ARM's build of a gcc toolchain,
    or commercial gcc toolchains). The biggest problem with microcontroller manufacturer's tools is usually the SDK's that are frequently horrible
    in all sorts of ways.

    But I agree with your advice - where possible, use ARM's gcc toolchain
    build for ARM development. And make sure your project build is
    independent of any IDE, whether it is from the vendor or independent.
    IDE's are great for coding, and vendor-supplied IDE's can give good
    debugging tools, but you want the project build itself to be independent.

    What he said, defintely: Avoid vendor-specific IDEs and SDKs like the
    plague.

    Demo apps and libraries from Silicon vendors are usually awful -- even
    worse than the toolchains. I'm pretty sure they're written by interns
    who think that to be "professional" it has to incorporate layers and
    layers of macros and objects and abstrcation and polymorphism and
    whatnot.

    As a result I rememeber failing to get a vendor's "hello world" demo
    to run on a Cortex-M0+ because it was too large for both the flash and
    RAM available on the lower end of the family. And it wsan't even
    using "printf" just a "low level" serial port driver that should have
    been a few hundred bytes of code but was actually something like
    10KB..

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Grant Edwards on Sun Nov 24 14:03:08 2024
    On 11/24/2024 10:12 AM, Grant Edwards wrote:
    On 2024-11-24, David Brown <david.brown@hesbynett.no> wrote:

    [And I'm STILL not seeing your posts. <frown> Something must
    be broken in my server. Yet the telephone system seems to be
    working properly! Yet another thing to look into...]

    Some vendor-supplied toolchains are not bad, but some are definitely
    subpar - and often many years behind the versions you get from
    manufacturer independent suppliers (like ARM's build of a gcc toolchain,
    or commercial gcc toolchains). The biggest problem with microcontroller
    manufacturer's tools is usually the SDK's that are frequently horrible
    in all sorts of ways.

    I think vendors offer tools for much the same reason as they
    write app notes or illustrate "typical applications". Their
    goal is to get you USING their product, as quickly as
    possible. If you had to hunt for development tools, then
    you would likely bias your device selection based on the
    availability and cost of said tools.

    [I worked with a firm that offered a "development system" (compile/ASM/debug suite plus hardware ICE, in the days before JTAG and on-chip debug
    existed) for an obscure, old processor. They recounted a story where
    a customer purchased said tool -- for a fair bit of money. And, promptly RETURNED it with a *nasty* note complaining about the (low) quality
    of the fabrication! Some time later, they REordered the system...
    when they discovered there were no other offerings in that market!]

    Note the inroads Microchip made (esp with hobbyists) by offering
    free/low cost tools for their devices. I suspect their devices
    were not the ideal choices for those applications -- but, the value
    of HAVING the tools without spending kilobucks to buy them weighed
    heavily in their decisions!

    But I agree with your advice - where possible, use ARM's gcc toolchain
    build for ARM development. And make sure your project build is
    independent of any IDE, whether it is from the vendor or independent.
    IDE's are great for coding, and vendor-supplied IDE's can give good
    debugging tools, but you want the project build itself to be independent.

    This is a given, regardless. "Sole source" suppliers are always a risk.
    Moving from one ARM to another (vs a totally different architecture)
    saves a lot -- but, you are still stuck with the choices the fab made
    in what they decided to offer.

    What he said, defintely: Avoid vendor-specific IDEs and SDKs like the
    plague.

    Demo apps and libraries from Silicon vendors are usually awful -- even
    worse than the toolchains. I'm pretty sure they're written by interns
    who think that to be "professional" it has to incorporate layers and
    layers of macros and objects and abstrcation and polymorphism and
    whatnot.

    The same is often true of "app notes" for hardware components.

    I interviewed a prospective client about a project. Somewhere
    along the line he "proudly" presented his proposed "solution"
    (then, what do you need ME for?).

    I looked at it (schematic) and replied: "This won't work."
    I.e., there were signals with no driving sources! He then
    admitted to copying it from an app note (said reproduction
    later verified to have been accurate; the app note was in error!)

    But, you aren't likely going to RUN those apps. And, libraries
    can be rebuilt and redesigned. So, you aren't at their "mercy"
    for those things.

    OTOH, if the vendor has some knowledge of a device defect (that
    they aren't eager to publicize -- "trade secrets") but their
    tools are aware of it and SILENTLY work-around it, then they
    have a leg up on a third-party who is trying to DEDUCE how
    the device works from the PUBLISHED knowledge (and personal
    observations).

    E.g., I would be happier knowing that a compiler would avoid
    generating code that could tickle vulnerabilities in a
    system (e.g., memory) over one that blindly strives for
    performance (or ignorance).

    Or, a compiler that knows enough about the SPECIFIC processor
    (not just the FAMILY) to know how to more finely optimize its
    scheduling of instructions.

    [The days of expecting the code to just implement the expressed
    algorithm are long past. "What ELSE are you going to do FOR me?"]

    As a result I rememeber failing to get a vendor's "hello world" demo
    to run on a Cortex-M0+ because it was too large for both the flash and
    RAM available on the lower end of the family. And it wsan't even
    using "printf" just a "low level" serial port driver that should have
    been a few hundred bytes of code but was actually something like
    10KB..

    But, if they published that code, you could inspect it, determine
    what it was TRYING to do and fix it (or, take a lesson from it).

    It's amusing when these sorts of things are treated as "proprietary information" ("secret"). There's nothing revolutionary in a GENERIC
    standard library implementation (though there are varying degrees
    of performance that can be obtained from those that are SPECIALIZED)

    --- SoupGate-Win32 v1.05
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  • From David Brown@21:1/5 to Grant Edwards on Mon Nov 25 09:37:47 2024
    On 24/11/2024 18:12, Grant Edwards wrote:
    On 2024-11-24, David Brown <david.brown@hesbynett.no> wrote:

    Some vendor-supplied toolchains are not bad, but some are definitely
    subpar - and often many years behind the versions you get from
    manufacturer independent suppliers (like ARM's build of a gcc toolchain,
    or commercial gcc toolchains). The biggest problem with microcontroller
    manufacturer's tools is usually the SDK's that are frequently horrible
    in all sorts of ways.

    But I agree with your advice - where possible, use ARM's gcc toolchain
    build for ARM development. And make sure your project build is
    independent of any IDE, whether it is from the vendor or independent.
    IDE's are great for coding, and vendor-supplied IDE's can give good
    debugging tools, but you want the project build itself to be independent.

    What he said, defintely: Avoid vendor-specific IDEs and SDKs like the
    plague.

    I didn't /quite/ say that. Avoid relying on them for your builds, was
    what I said. The last thing you want is your project being dependent on whatever version of the IDE and SDK the supplier provides at a given
    time. For a serious project, you want to be able to take a new
    computer, check out the old source, install the specific toolchain you
    use for the project, and re-build to get exactly the same binary. And
    you want to be able to do that a decade later.

    I /do/ make use of parts of SDKs. But I figure out what I need, and
    copy the source into my project structure. The main point is to avoid
    having your project change because it is linked to some SDK stuff that
    gets updated by the manufacturer's tools. Library updates happen when
    /I/ want them to happen, not on someone else's schedule.

    Often, the actual SDK stuff is very inefficient and bizarrely
    structured. But it can be convenient for things like initialisation of
    complex peripherals, and that's fine - you don't (normally) need
    efficiency during initialisation. For real-time access - setting your
    pwm values, using your gpio's, etc., - it is usually best to handle
    things "manually".

    And of course the project build gets controlled by external tools. I
    like hand-written makefiles, but cmake or whatever suits is fine.

    Vendor-supplied tools can be very useful for debugging, however, as well
    as being convenient for startup code, device initialisation, examples,
    and so on. I am not at all against using them - use every tool you can
    get hold of that makes your job easier! But don't make your actual
    project binaries dependent on them.


    Demo apps and libraries from Silicon vendors are usually awful -- even
    worse than the toolchains. I'm pretty sure they're written by interns
    who think that to be "professional" it has to incorporate layers and
    layers of macros and objects and abstrcation and polymorphism and
    whatnot.


    Often the demos are terrible, I agree. And they are often wildly
    inconsistent. But that doesn't mean they are completely useless - they
    can be inspirational too, and can be helpful to see what you are missing
    when your own code doesn't work.

    As a result I rememeber failing to get a vendor's "hello world" demo
    to run on a Cortex-M0+ because it was too large for both the flash and
    RAM available on the lower end of the family. And it wsan't even
    using "printf" just a "low level" serial port driver that should have
    been a few hundred bytes of code but was actually something like
    10KB..


    I think the clearest "war story" I have seen of that kind was for a tiny
    8-bit device from Freescale. The chip had perhaps 2K of flash. Since
    this was a one-off use of the chip and I didn't want to read more
    manuals than I needed to, I use the vendor IDE "wizard" to make the initialisation code and a "driver" for the ADC. The resulting code was
    about 3.5 KB - for the 2 KB microcontroller. So I read the manual and
    found that the ADC peripheral needed one single bit set to make it run
    as I needed.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Brown@21:1/5 to Don Y on Mon Nov 25 11:41:58 2024
    On 24/11/2024 22:03, Don Y wrote:
    On 11/24/2024 10:12 AM, Grant Edwards wrote:
    On 2024-11-24, David Brown <david.brown@hesbynett.no> wrote:

    [And I'm STILL not seeing your posts.  <frown>  Something must
    be broken in my server.  Yet the telephone system seems to be
    working properly!  Yet another thing to look into...]

    Perhaps Grant could re-post for me here?


    Maybe you killfiled me?

    I think you are using news.eternal-september.org for your server, which
    is the same as me.


    Some vendor-supplied toolchains are not bad, but some are definitely
    subpar - and often many years behind the versions you get from
    manufacturer independent suppliers (like ARM's build of a gcc toolchain, >>> or commercial gcc toolchains).  The biggest problem with microcontroller >>> manufacturer's tools is usually the SDK's that are frequently horrible
    in all sorts of ways.

    I think vendors offer tools for much the same reason as they
    write app notes or illustrate "typical applications".  Their
    goal is to get you USING their product, as quickly as
    possible.  If you  had to hunt for development tools, then
    you would likely bias your device selection based on the
    availability and cost of said tools.


    Yes.

    Sometimes I think they could put more effort into making sure you want
    to /keep/ using their products!

    [I worked with a firm that offered a "development system"
    (compile/ASM/debug
    suite plus hardware ICE, in the days before JTAG and on-chip debug
    existed) for an obscure, old processor.  They recounted a story where
    a customer purchased said tool -- for a fair bit of money.  And, promptly RETURNED it with a *nasty* note complaining about the (low) quality
    of the fabrication!  Some time later, they REordered the system...
    when they discovered there were no other offerings in that market!]


    That's it - you don't have to be good to conquer a market, you just have
    to be the best available.

    Note the inroads Microchip made (esp with hobbyists) by offering
    free/low cost tools for their devices.  I suspect their devices
    were not the ideal choices for those applications -- but, the value
    of HAVING the tools without spending kilobucks to buy them weighed
    heavily in their decisions!


    The success of Microchip here has always confused me. Their hardware development tools were not good or particularly cheap when I used them
    in the late 1990's. Their software development tools were terrible. I remember IDE's that wouldn't work on newer PC's, only a fairly basic
    assembler with very limited debug support, and C compilers that were extraordinarily expensive, full of bugs, incompatibilities and crippling limitations.

    They did have a few things going for them - the PIC microcontrollers
    were very robust, came in hobby-friendly packages, and never went out of production. But their tools, beyond the lowest-level basics, were
    expensive and very poor quality, even compared to the competition at the
    time. They still are - I don't know any other manufacturer that still
    charges for toolchains. And their prices are obscene - $1.6k per year
    to enable optimisation on their packaging of gcc-based toolchains for
    ARM and MIPs. The only effort Microchip have made to justify the price
    is all their work in trying to make it look like they wrote the compiler
    and it's not just gcc with added licensing locks.


    But I agree with your advice - where possible, use ARM's gcc toolchain
    build for ARM development.  And make sure your project build is
    independent of any IDE, whether it is from the vendor or independent.
    IDE's are great for coding, and vendor-supplied IDE's can give good
    debugging tools, but you want the project build itself to be
    independent.

    This is a given, regardless.  "Sole source" suppliers are always a risk. Moving from one ARM to another (vs a totally different architecture)
    saves a lot -- but, you are still stuck with the choices the fab made
    in what they decided to offer.

    What he said, defintely: Avoid vendor-specific IDEs and SDKs like the
    plague.

    Demo apps and libraries from Silicon vendors are usually awful -- even
    worse than the toolchains. I'm pretty sure they're written by interns
    who think that to be "professional" it has to incorporate layers and
    layers of macros and objects and abstrcation and polymorphism and
    whatnot.

    The same is often true of "app notes" for hardware components.

    I interviewed a prospective client about a project.  Somewhere
    along the line he "proudly" presented his proposed "solution"
    (then, what do you need ME for?).

    I looked at it (schematic) and replied:  "This won't work."
    I.e., there were signals with no driving sources!  He then
    admitted to copying it from an app note (said reproduction
    later verified to have been accurate; the app note was in error!)

    But, you aren't likely going to RUN those apps.  And, libraries
    can be rebuilt and redesigned.  So, you aren't at their "mercy"
    for those things.

    OTOH, if the vendor has some knowledge of a device defect (that
    they aren't eager to publicize -- "trade secrets") but their
    tools are aware of it and SILENTLY work-around it, then they
    have a leg up on a third-party who is trying to DEDUCE how
    the device works from the PUBLISHED knowledge (and personal
    observations).

    Call me naïve, but I don't see this happening much. The manufacturers
    we use for microcontrollers tend to be quite open about defects and workarounds, as are ARM (and as I wrote earlier, for the Cortex-M
    devices the cores come ready-made from ARM, with a lot less scope for vendor-specific bugs). A vendor that tried to hide a known defect in an
    ARM core would suffer - they would get caught, and getting on the bad
    side of ARM is not worth it.

    But it is certainly possible that a vendor supplied toolchain build will
    have the workaround before it has made it into other toolchains. Hiding defects or lying about them is bad - but being first to have a fix is fine.


    E.g., I would be happier knowing that a compiler would avoid
    generating code that could tickle vulnerabilities in a
    system (e.g., memory) over one that blindly strives for
    performance (or ignorance).

    Sure. But you are worrying about nothing, I think. Have you ever seen
    a compiler where you know the developers /intentionally/ ignored flaws
    or incorrect code generation?


    Or, a compiler that knows enough about the SPECIFIC processor
    (not just the FAMILY) to know how to more finely optimize its
    scheduling of instructions.

    That's a good reason for using compiler builds from ARM, rather than microcontroller vendors - they know the cpus better. Target-specific optimisations are always passed on to mainline gcc (and clang/llvm), but
    can be in ARM's builds earlier. A vendor that builds its own toolchains
    might pull in these patches too, but they might not. (Most vendors of
    ARM microcontrollers use the compiler builds from ARM, but these might
    be a bit dated.)


    [The days of expecting the code to just implement the expressed
    algorithm are long past.  "What ELSE are you going to do FOR me?"]

    As a result I rememeber failing to get a vendor's "hello world" demo
    to run on a Cortex-M0+ because it was too large for both the flash and
    RAM available on the lower end of the family.  And it wsan't even
    using "printf" just a "low level" serial port driver that should have
    been a few hundred bytes of code but was actually something like
    10KB..

    But, if they published that code, you could inspect it, determine
    what it was TRYING to do and fix it (or, take a lesson from it).

    It's amusing when these sorts of things are treated as "proprietary information" ("secret").  There's nothing revolutionary in a GENERIC standard library implementation (though there are varying degrees
    of performance that can be obtained from those that are SPECIALIZED)


    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Grant Edwards@21:1/5 to David Brown on Mon Nov 25 15:18:35 2024
    On 2024-11-25, David Brown <david.brown@hesbynett.no> wrote:

    I think the clearest "war story" I have seen of that kind was for a
    tiny 8-bit device from Freescale. The chip had perhaps 2K of flash.
    Since this was a one-off use of the chip and I didn't want to read
    more manuals than I needed to, I use the vendor IDE "wizard" to make
    the initialisation code and a "driver" for the ADC. The resulting
    code was about 3.5 KB - for the 2 KB microcontroller. So I read the
    manual and found that the ADC peripheral needed one single bit set
    to make it run as I needed.

    One of the problems that the SDK authors have to try to deal with is
    that the peripherals have gotten "too" versatile. They've got a
    polled mode, an interrupt driven mode, a DMA mode, a burst mode, a
    batch mode, a right-side up mode, an updisde-down mode, and three
    compatibility modes so they'll work like products from 40 years ago.

    The SDK "drivers" always try to support all the modes in all possible combinations and sometimes even allow you to switch back and forth
    while the thing is running. They'll have open() and close() methods
    for no apparent reason for devices that don't need to be opened or
    closed.

    As a result, you end up with 3.5KB of driver for an ADC.

    Then, in the real world. 99.99% of applicatoins only use one very
    sepecific mode. You either read the hardware description and write
    code from scratch (though the #defines for register offsets are
    useful), or you pick your way through the "driver" code for you
    particular set of modes/choices to find the handful of lines of code
    that you need.

    Rather than providing a full-up "driver" I would find it a _lot_ more
    useful if they just provided documented code snippets to perform some
    of the basic operations that one needs to perform.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Brown@21:1/5 to Grant Edwards on Mon Nov 25 17:33:29 2024
    On 25/11/2024 16:18, Grant Edwards wrote:
    On 2024-11-25, David Brown <david.brown@hesbynett.no> wrote:

    I think the clearest "war story" I have seen of that kind was for a
    tiny 8-bit device from Freescale. The chip had perhaps 2K of flash.
    Since this was a one-off use of the chip and I didn't want to read
    more manuals than I needed to, I use the vendor IDE "wizard" to make
    the initialisation code and a "driver" for the ADC. The resulting
    code was about 3.5 KB - for the 2 KB microcontroller. So I read the
    manual and found that the ADC peripheral needed one single bit set
    to make it run as I needed.

    One of the problems that the SDK authors have to try to deal with is
    that the peripherals have gotten "too" versatile. They've got a
    polled mode, an interrupt driven mode, a DMA mode, a burst mode, a
    batch mode, a right-side up mode, an updisde-down mode, and three compatibility modes so they'll work like products from 40 years ago.

    The SDK "drivers" always try to support all the modes in all possible combinations and sometimes even allow you to switch back and forth
    while the thing is running. They'll have open() and close() methods
    for no apparent reason for devices that don't need to be opened or
    closed.

    As a result, you end up with 3.5KB of driver for an ADC.

    Then, in the real world. 99.99% of applicatoins only use one very
    sepecific mode. You either read the hardware description and write
    code from scratch (though the #defines for register offsets are
    useful), or you pick your way through the "driver" code for you
    particular set of modes/choices to find the handful of lines of code
    that you need.

    Rather than providing a full-up "driver" I would find it a _lot_ more
    useful if they just provided documented code snippets to perform some
    of the basic operations that one needs to perform.


    You are absolutely correct here.

    Manufacturers should employ some developers with experience actually
    /using/ microcontrollers. The hardware designers should not be allowed
    to put in any features that don't pass a "yes, I'd use that" test. Then
    the SDK designers (if such people exist) would get similar reality checks.

    And the SDK people should learn that the year is 2024. We don't need
    C90 compatibility - we want decent /modern/ interfaces using all useful
    the bells and whistles from C17, C++20, and gcc extensions so we can
    write safer, clearer and more efficient code. Leave the shitty macros,
    void* pointers and run-time checking of compile-time values behind.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Grant Edwards on Mon Nov 25 13:47:41 2024
    On 11/25/2024 8:18 AM, Grant Edwards wrote:
    On 2024-11-25, David Brown <david.brown@hesbynett.no> wrote:

    I think the clearest "war story" I have seen of that kind was for a
    tiny 8-bit device from Freescale. The chip had perhaps 2K of flash.
    Since this was a one-off use of the chip and I didn't want to read
    more manuals than I needed to, I use the vendor IDE "wizard" to make
    the initialisation code and a "driver" for the ADC. The resulting
    code was about 3.5 KB - for the 2 KB microcontroller. So I read the
    manual and found that the ADC peripheral needed one single bit set
    to make it run as I needed.

    One of the problems that the SDK authors have to try to deal with is
    that the peripherals have gotten "too" versatile. They've got a
    polled mode, an interrupt driven mode, a DMA mode, a burst mode, a
    batch mode, a right-side up mode, an updisde-down mode, and three compatibility modes so they'll work like products from 40 years ago.

    The SDK "drivers" always try to support all the modes in all possible combinations and sometimes even allow you to switch back and forth
    while the thing is running. They'll have open() and close() methods
    for no apparent reason for devices that don't need to be opened or
    closed.

    As a result, you end up with 3.5KB of driver for an ADC.

    To be fair, they often have to include the initialization/configuration
    code that a "real" system would have put elsewhere, hiding the true
    size of the code required to use the peripheral.

    Then, in the real world. 99.99% of applicatoins only use one very
    sepecific mode. You either read the hardware description and write
    code from scratch (though the #defines for register offsets are
    useful), or you pick your way through the "driver" code for you
    particular set of modes/choices to find the handful of lines of code
    that you need.

    Rather than providing a full-up "driver" I would find it a _lot_ more
    useful if they just provided documented code snippets to perform some
    of the basic operations that one needs to perform.

    Yes.

    Though the SDK has value if only for SUGGESTING names for the various
    symbolic constants needed to configure the device.

    The AM62x family reference manual is 16000 pages -- 12000 of those
    are "register descriptions (tabulated). That's a shitload of
    #defines to have to create from scratch!

    Given that the SDK had to come up with unique names for all of them,
    it's a headstart in designing your own naming convention for the device.

    [I'm going to bow out of this discussion as there is something clearly
    wrong with my server/attendant -- and fixing it is not a current priority.
    The fourth quarter is traditionally my "update equipment, applications, licenses" period along with the various birthdays, anniversaries and
    holidays that crowd into those three months. The NNTP server/attendant
    wasn't on the list for an upgrade as I *thought* it was working well
    (seems to be for other newsgroups and the phone attendant hasn't had
    any problems!)

    I'll see if I can rescue another box and rebuild it (silly not to
    take advantage of that need to also upgrade the hardware!)]

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to All on Sat Nov 23 01:15:51 2024
    I'm looking to move my design onto said platform.

    Any first-hand experiences to share?

    Bugs in silicon, toolchain, support, etc.?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)